Document and Entity Information	3 Months Ended
Document and Entity Information	Jun. 28, 2015	Jul. 24, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	HAWKINS INC
Entity Central Index Key	0000046250
Document Type	10-Q
Document Period End Date	Jun. 28, 2015
Amendment Flag	false
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--04-03
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		10,654,509

Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
CURRENT ASSETS:
Cash and cash equivalents	$ 18,071	$ 18,639
Investments available-for-sale	13,959	14,485
Trade receivables — less allowance for doubtful accounts: $441 as of June 28, 2015 and $445 as of March 29, 2015	39,764	40,355
Inventories	39,084	37,028
Income taxes receivable	0	732
Prepaid expenses and other current assets	2,527	3,101
Total current assets	113,405	114,340
PROPERTY, PLANT, AND EQUIPMENT:
PROPERTY, PLANT, AND EQUIPMENT:	175,861	172,772
Less accumulated depreciation and amortization	80,739	79,042
Net property, plant, and equipment	95,122	93,730
Goodwill	11,750	11,750
Intangible assets — less accumulated amortization: $4,242 as of June 28, 2015 and $3,933 as of March 29, 2015	11,070	11,154
Long-term investments available for sale	16,101	17,249
Other	480	239
Total other assets	39,401	40,392
Total assets	247,928	248,462
CURRENT LIABILITIES:
Accounts payable	18,345	20,083
Dividends payable	0	4,038
Accrued payroll and employee benefits	4,775	6,122
Deferred income taxes	2,698	2,698
Income tax payable	829	0
Other current liabilities	3,763	3,402
Total current liabilities	30,410	36,343
PENSION WITHDRAWAL LIABILITY	6,513	6,589
DEFERRED INCOME TAXES	656	1,588
OTHER LONG-TERM LIABILITIES	10,014	9,978
Total liabilities	47,593	54,498
COMMITMENTS AND CONTINGENCIES	0	0
SHAREHOLDERS’ EQUITY:
Common stock; authorized: 30,000,000 shares of $0.05 par value; 10,569,764 and 10,564,949 shares issued and outstanding as of June 28, 2015 and March 29, 2015, respectively	528	528
Additional paid-in capital	50,426	50,901
Retained earnings	149,358	142,567
Accumulated other comprehensive income (loss)	23	(32)
Total shareholders’ equity	200,335	193,964
Total liabilities and shareholders’ equity	$ 247,928	$ 248,462

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, trade receivables	$ 441	$ 445
Intangible assets accumulated amortization	$ 4,242	$ 3,933
Shares authorized	30,000,000	30,000,000
Common stock, par value (usd per share)	$ 0.05	$ 0.05
Common Stock, Shares, Issued	10,569,764	10,564,949
Common Stock, Shares, Outstanding	10,569,764	10,564,949

Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jun. 28, 2015	Jun. 29, 2014
Income Statement [Abstract]
Sales	$ 101,496	$ 98,036
Cost of sales	(80,761)	(79,540)
Gross profit	20,735	18,496
Selling, general and administrative expenses	(9,891)	(8,875)
Operating income	10,844	9,621
Interest income, net	21	14
Income before income taxes	10,865	9,635
Income tax provision	(4,074)	(3,614)
Net income	$ 6,791	$ 6,021
Weighted average number of shares outstanding - basic	10,580,542	10,570,041
Weighted average number of shares outstanding - diluted	10,628,409	10,613,738
Basic earnings per share
Basic earnings per share	$ 0.64	$ 0.57
Diluted earnings per share
Diluted earnings per share	$ 0.64	$ 0.57
Cash dividends declared per common share	$ 0	$ 0

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 28, 2015	Jun. 29, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 6,791	$ 6,021
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale investments	55	(8)
Total comprehensive income	$ 6,846	$ 6,013

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 28, 2015	Jun. 29, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 6,791	$ 6,021
Reconciliation to cash flows:
Depreciation and amortization	3,564	2,984
Stock compensation expense	457	405
Loss (gain) from property disposals	13	(4)
Changes in operating accounts providing (using) cash:
Trade receivables	591	(1,971)
Inventories	(2,056)	(8,129)
Accounts payable	(1,333)	3,763
Accrued liabilities	(1,995)	(1,695)
Income taxes	1,561	(688)
Other	333	738
Net cash provided by operating activities	7,926	1,424
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant, and equipment	(5,181)	(3,298)
Purchases of investments	(2,194)	(8,798)
Sale and maturities of investments	3,960	4,520
Other	(110)	18
Net cash used in investing activities	(3,525)	(7,558)
CASH FLOWS FROM FINANCING ACTIVITIES:
Cash dividends paid	(4,038)	(3,823)
Shares surrendered for payroll taxes	(379)	(295)
Shares repurchased	(552)	(1,431)
Net cash used in financing activities	(4,969)	(5,549)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(568)	(11,683)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	18,639	33,486
CASH AND CASH EQUIVALENTS, END OF PERIOD	18,071	21,803
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for income taxes	2,513	4,325
Noncash investing activities - Capital expenditures in accounts payable	$ 720	$ 185

Basis of Presentation	3 Months Ended
Basis of Presentation	Jun. 28, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the instructions for Form 10-Q and, accordingly, do not include all information and footnotes required by generally accepted accounting principles for complete financial statements. These financial statements should be read in conjunction with the consolidated financial statements and footnotes included in our Annual Report on Form 10-K for the fiscal year ended March 29, 2015, previously filed with the Securities and Exchange Commission (“SEC”). In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments necessary to present fairly our financial position and the results of our operations and cash flows for the periods presented. All adjustments made to the interim condensed consolidated financial statements were of a normal recurring nature. All significant intercompany accounts and transactions have been eliminated in consolidation. The accounting policies we follow are set forth in “Item 8. Financial Statements and Supplementary Data, Note 1 – Nature of Business and Significant Accounting Policies” to our consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended March 29, 2015, filed with the SEC on May 28, 2015. There has been no significant change in our accounting policies since the end of fiscal 2015. The results of operations for the three months ended June 28, 2015 are not necessarily indicative of the results that may be expected for the full year. References to fiscal 2015 refer to the fiscal year ended March 29, 2015 and references to fiscal 2016 refer to the fiscal year ending April 3, 2016. As compared to our normal 52-week fiscal years, fiscal 2016 will be a 53-week year, with the extra week to be recorded in our fourth quarter’s results of operations. Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board issued new accounting requirements for recognition of revenue from contracts with customers. The requirements of the new standard will be effective for annual reporting periods beginning after December 15, 2017 (our fiscal year ending March 31, 2019), and interim periods within those annual periods. We are currently evaluating the impact of this accounting pronouncement on our results of operations and financial position.

Earnings per Share

3 Months Ended

Jun. 28, 2015

Earnings Per Share [Abstract]

Earnings per Share

Basic earnings per share (“EPS”) are computed by dividing net earnings by the weighted-average number of common shares outstanding. Diluted EPS includes the incremental shares assumed to be issued upon the exercise of stock options and the incremental shares assumed to be issued as performance units and restricted stock. Basic and diluted EPS were calculated using the following:



	Three Months Ended
	June 28, 2015	June 29, 2014
Weighted-average common shares outstanding—basic	10,580,542	10,570,041
Dilutive impact of stock options, performance units, and restricted stock	47,867	43,697
Weighted-average common shares outstanding—diluted	10,628,409	10,613,738

For the three months ended June 28, 2015 and June 29, 2014, there were no shares or stock options excluded from the calculation of weighted-average common shares for diluted EPS.

Business Combinations

3 Months Ended

Jun. 28, 2015

Business Combinations [Abstract]

Business Combination Disclosure [Text Block]

Business Combinations

Acquisition of The Dumont Company, Inc.: In the third quarter of fiscal 2015, we acquired substantially all of the assets of The Dumont Company, Inc. (“Dumont”) under the terms of an asset purchase agreement with Dumont and its shareholders. We paid $10.1 million in cash including a working capital adjustment in the third quarter of fiscal 2015, using available cash on hand to fund the acquisition. Dumont was a water treatment chemical distribution company with revenues of approximately $14 million in calendar year 2013. Through this acquisition we added seven operating locations across Florida. The results of operations since the acquisition date, and the assets, including the goodwill associated with this acquisition, are included in our Water Treatment segment. Costs associated with this transaction were not material to our company and were expensed as incurred.

The acquisition has been accounted for under the acquisition method of accounting, under which the total purchase price is allocated to the net tangible and intangible assets of Dumont acquired in connection with the acquisition based on their estimated fair values. We estimated the fair values of the assets acquired and liabilities assumed using a discounted cash flow analysis (income approach). The following table summarizes the preliminary allocation of the purchase price to the fair values assigned to the assets acquired and liabilities assumed at the date of the Dumont acquisition:



(In thousands)	Amount
Accounts receivable	$	1,358
Inventory	859
Other assets	159
Property, plant, and equipment	702
Intangible assets	3,509
Current liabilities	(877		)
Net assets acquired	5,710
Goodwill	4,358
Total purchase price	$	10,068

The goodwill recognized as a result of this acquisition is primarily attributable to strategic and synergistic benefits, as well as the assembled workforce. Such goodwill is expected to be deductible for tax purposes.

The preliminary allocation of the purchase price to the assets acquired and liabilities assumed resulted in the recognition of the following intangible assets:



(In thousands)	Amount		Life (in years)
Customer relationships	$	2,810	20
Trade Name	699		4
	$	3,509

Cash and Cash Equivalents and Investments

3 Months Ended

Jun. 28, 2015

Cash and Cash Equivalents [Abstract]

Cash and Cash Equivalents and Investments

The following table presents information about our financial assets that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.



	June 28, 2015
(In thousands)	June 28, 2015		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	18,071	$	18,071	$	—	$	—
Certificates of deposit	28,243		—		28,243		—
Municipal bonds	1,817		—		1,817		—

	March 29, 2015
(In thousands)	March 29, 2015		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	18,639	$	18,639	$	—	$	—
Certificates of deposit	29,136		—		29,136		—
Municipal bonds	2,598		—		2,598		—

Our financial assets that are measured at fair value on a recurring basis and fall within valuation technique Level 2 are certificates of deposit (“CDs”) and municipal bonds, with original maturities ranging from three months to three years. The CDs and municipal bonds are classified as investments in current assets and noncurrent assets on the condensed consolidated balance sheets. As of June 28, 2015, the combined CDs and municipal bonds had a fair value of $14.0 million in current assets and $16.1 million in noncurrent assets compared to CDs and municipal bonds with a fair value of $14.5 million in current assets and $17.2 million in noncurrent assets as of March 29, 2015.

Inventories

3 Months Ended

Jun. 28, 2015

Inventory Disclosure [Abstract]

Inventories

Inventories at June 28, 2015 and March 29, 2015 consist of the following:



	June 28, 2015			March 29, 2015
(In thousands)	June 28, 2015			March 29, 2015
Inventory (FIFO basis)	$	44,645		$	42,567
LIFO reserve	(5,561		)	(5,539		)
Net inventory	$	39,084		$	37,028

The first in, first out (“FIFO”) value of inventories accounted for under the last in, first out (“LIFO”) method was $41.4 million at June 28, 2015 and $39.0 million at March 29, 2015. The remainder of the inventory was valued and accounted for under the FIFO method.

The LIFO reserve changed nominally during the three months ended June 28, 2015, and increased $0.5 million during the three months ended June 29, 2014. The valuation of LIFO inventory for interim periods is based on our estimates of year-end inventory levels and costs.

Goodwill and Intangible Assets

3 Months Ended

Jun. 28, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

Goodwill. The carrying amount of goodwill was $11.7 million as of June 28, 2015 and March 29, 2015.

Intangible assets. A summary of our intangible assets as of June 28, 2015 and March 29, 2015 is as follows:



	June 28, 2015							March 29, 2015
(In thousands)	Gross Amount		Accumulated Amortization			Net		Gross Amount		Accumulated Amortization			Net
Finite-life intangible assets
Customer relationships	$	9,948	$	(1,837	)	$	8,111	$	9,723	$	(1,697	)	$	8,026
Trademarks and trade names	2,034		(754		)	1,280		2,034		(667		)	1,367
Trade secrets	962		(919		)	43		962		(896		)	66
Carrier relationships	800		(395		)	405		800		(337		)	463
Other finite-life intangible assets	341		(337		)	4		341		(336		)	5
Total finite-life intangible assets	14,085		(4,242		)	9,843		13,860		(3,933		)	9,927
Indefinite-life intangible assets	1,227		—			1,227		1,227		—			1,227
Total intangible assets	$	15,312	$	(4,242	)	$	11,070	$	15,087	$	(3,933	)	$	11,154

Share Based Compensation

3 Months Ended

Jun. 28, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-Based Compensation

Performance-Based Restricted Stock Units. Our Board of Directors (the “Board”) approved a performance-based equity compensation arrangement for our executive officers during the first quarters of each of fiscal 2016 and 2015. These performance-based arrangements provide for the grant of performance-based restricted stock units that represent a possible future issuance of restricted shares of our common stock based on a pre-tax income target for the applicable fiscal year. The actual number of restricted shares to be issued to each executive officer is determined when our final financial information becomes available after the applicable fiscal year and will be between zero shares and 44,446 shares in the aggregate for fiscal 2016. The restricted shares issued will fully vest two years after the last day of the fiscal year on which the performance is based. We are recording the compensation expense for the outstanding performance share units and the converted restricted stock over the life of the awards.

The following table represents the restricted stock activity for the three months ended June 28, 2015:



	Shares		Weighted- Average Grant Date Fair Value
Unvested at beginning of period	53,580		$	37.55
Granted	37,309		40.89
Vested	(28,648	)	40.25
Unvested at end of period	62,241		$	38.31

We recorded compensation expense of $0.3 million related to performance share units and restricted stock for the three months ended June 28, 2015 and June 29, 2014. Substantially all of the compensation expense was recorded in selling, general and administrative expenses in the condensed consolidated statements of income.

Restricted Stock Awards. As part of their retainer, each non-employee director receives an annual grant of restricted stock for their Board services. The restricted stock awards are expensed over the requisite vesting period, which is one year from the date of issuance, based on the market value on the date of grant. As of June 28, 2015, there were 7,077 shares of restricted stock with a weighted averaged grant date fair value of $34.61 outstanding under this program. Compensation expense for the three months ended June 28, 2015 and June 29, 2014 related to restricted stock awards to the Board was $0.1 million.

Stock Option Awards. The Board previously approved a long-term incentive equity compensation arrangement for our executive officers that provided for the grant of non-qualified stock options that vested at the end of a three-year period. No stock options have been granted since our fiscal year ended March 28, 2010. During fiscal 2015, 9,333 options were exercised with an exercise price of $19.90. No expense was recorded in fiscal 2015 or fiscal 2016 related to the value of stock options.

Share Repurchase Program	3 Months Ended
Share Repurchase Program	Jun. 28, 2015
Share Repurchase Program [Abstract]
Share Repurchase Program	Share Repurchase Program On May 29, 2014, our Board authorized a share repurchase program of up to 300,000 shares of our outstanding common shares. Under the program, we are authorized to repurchase shares for cash on the open market or in privately negotiated transactions subject to applicable securities laws and regulations. Upon repurchase of the shares, we reduced our common stock for the par value of the shares with the excess applied against additional paid-in capital. During the first quarter of fiscal 2016, we repurchased 13,850 shares of common stock with an aggregate purchase price of $0.6 million. During fiscal 2015, we repurchased 59,602 shares at an aggregate purchase price of $2.2 million, of which 39,170 shares with an aggregate purchase price of $1.4 million were repurchased during the first quarter.

Segment Information

3 Months Ended

Jun. 28, 2015

Segment Reporting [Abstract]

Segment Information

We have two reportable segments: Industrial and Water Treatment. The accounting policies of the segments are the same as those described in the summary of significant accounting policies as disclosed in our fiscal 2015 Annual Report on Form 10-K. Product costs and expenses for each segment are based on actual costs incurred along with cost allocation of shared and centralized functions. We evaluate performance based on profit or loss from operations before income taxes not including nonrecurring gains and losses. Reportable segments are defined primarily by product and type of customer. Segments are responsible for the sales, marketing and development of their products and services. The segments do not have separate accounting, administration, customer service or purchasing functions. There are no intersegment sales and no operating segments have been aggregated. Given the nature of our business, it is not practical to disclose revenues from external customers for each product or each group of similar products. No single customer’s revenues amounted to 10% or more of our total revenue. Sales outside of the United States are immaterial and all assets are located within the United States.



(In thousands)	Industrial		Water Treatment		Total
Three months ended June 28, 2015:
Sales	$	67,588	$	33,908	$	101,496
Gross profit	10,714		10,021		20,735
Selling, general and administrative expenses	5,199		4,692		9,891
Operating income	5,515		5,329		10,844
Three months ended June 29, 2014:
Sales	$	67,546	$	30,490	$	98,036
Gross profit	9,361		9,135		18,496
Selling, general and administrative expenses	5,099		3,776		8,875
Operating income	4,262		5,359		9,621

Earnings per Share (Tables)

3 Months Ended

Jun. 28, 2015

Earnings Per Share [Abstract]

Summary of basic and diluted EPS



	Three Months Ended
	June 28, 2015	June 29, 2014
Weighted-average common shares outstanding—basic	10,580,542	10,570,041
Dilutive impact of stock options, performance units, and restricted stock	47,867	43,697
Weighted-average common shares outstanding—diluted	10,628,409	10,613,738

Business Combinations (Tables)

3 Months Ended

Jun. 28, 2015

Business Combinations [Abstract]

Schedule of Assets Acquired and Liabilities Assumed

The following table summarizes the preliminary allocation of the purchase price to the fair values assigned to the assets acquired and liabilities assumed at the date of the Dumont acquisition:



(In thousands)	Amount
Accounts receivable	$	1,358
Inventory	859
Other assets	159
Property, plant, and equipment	702
Intangible assets	3,509
Current liabilities	(877		)
Net assets acquired	5,710
Goodwill	4,358
Total purchase price	$	10,068

Schedule of Finite-Lived Intangible Assets Acquired

The preliminary allocation of the purchase price to the assets acquired and liabilities assumed resulted in the recognition of the following intangible assets:



(In thousands)	Amount		Life (in years)
Customer relationships	$	2,810	20
Trade Name	699		4
	$	3,509

Cash and Cash Equivalents and Investments (Tables)

3 Months Ended

Jun. 28, 2015

Cash and Cash Equivalents [Abstract]

Summary of financial assets and liabilities measured at fair value



	June 28, 2015
(In thousands)	June 28, 2015		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	18,071	$	18,071	$	—	$	—
Certificates of deposit	28,243		—		28,243		—
Municipal bonds	1,817		—		1,817		—

	March 29, 2015
(In thousands)	March 29, 2015		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	18,639	$	18,639	$	—	$	—
Certificates of deposit	29,136		—		29,136		—
Municipal bonds	2,598		—		2,598		—

Goodwill and Intangible Assets (Tables)

3 Months Ended

Jun. 28, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of intangible assets and goodwill

A summary of our intangible assets as of June 28, 2015 and March 29, 2015 is as follows:



	June 28, 2015							March 29, 2015
(In thousands)	Gross Amount		Accumulated Amortization			Net		Gross Amount		Accumulated Amortization			Net
Finite-life intangible assets
Customer relationships	$	9,948	$	(1,837	)	$	8,111	$	9,723	$	(1,697	)	$	8,026
Trademarks and trade names	2,034		(754		)	1,280		2,034		(667		)	1,367
Trade secrets	962		(919		)	43		962		(896		)	66
Carrier relationships	800		(395		)	405		800		(337		)	463
Other finite-life intangible assets	341		(337		)	4		341		(336		)	5
Total finite-life intangible assets	14,085		(4,242		)	9,843		13,860		(3,933		)	9,927
Indefinite-life intangible assets	1,227		—			1,227		1,227		—			1,227
Total intangible assets	$	15,312	$	(4,242	)	$	11,070	$	15,087	$	(3,933	)	$	11,154

Earning per Share (Details)	3 Months Ended
Earning per Share (Details)	Jun. 28, 2015	Jun. 29, 2014
Summary of basic and diluted EPS
Weighted-average common shares outstanding-basic (shares)	10,580,542	10,570,041
Dilutive impact of stock options, performance units, and restricted stock (shares)	47,867	43,697
Weighted-average common shares outstanding-diluted (shares)	10,628,409	10,613,738

Business Combinations (Details) (USD $)	0 Months Ended	3 Months Ended
Business Combinations (Details) (USD $)	Oct. 20, 2014	Dec. 28, 2014
The Dumont Company, Inc.
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 10,100,000
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	14,000,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable		1,358,000
Inventory		859,000
Other assets		159,000
Property, plant, and equipment		702,000
Intangible assets		3,509,000
Current liabilities		877,000
Net assets acquired		5,710,000
Goodwill		4,358,000
Total purchase price		10,068,000
The Dumont Company, Inc [Member]
Business Acquisition [Line Items]
Number of operating locations acquired	7
Customer Relationships [Member] \| The Dumont Company, Inc.
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	20 years
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets		2,810,000
Trade Names [Member] \| The Dumont Company, Inc.
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	4 years
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets		$ 699,000

Cash and Cash Equivalents and Investments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
Cash [Member] \| Total [Member]
Assets:
Cash/Certificates of deposit/Money market securities	$ 18,071	$ 18,639
Cash [Member] \| Level 1 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	18,071	18,639
Cash [Member] \| Level 2 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	0	0
Cash [Member] \| Level 3 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	0	0
Certificates of deposit [Member] \| Total [Member]
Assets:
Cash/Certificates of deposit/Money market securities	28,243	29,136
Certificates of deposit [Member] \| Level 1 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	0	0
Certificates of deposit [Member] \| Level 2 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	28,243	29,136
Certificates of deposit [Member] \| Level 3 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	0	0
Municipal bonds [Member] \| Total [Member]
Assets:
Cash/Certificates of deposit/Money market securities	1,817	2,598
Municipal bonds [Member] \| Level 1 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	0	0
Municipal bonds [Member] \| Level 2 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	1,817	2,598
Municipal bonds [Member] \| Level 3 [Member]
Assets:
Cash/Certificates of deposit/Money market securities	$ 0	$ 0

Cash and Cash Equivalents and Investments (Details Textual) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Jun. 28, 2015	Mar. 29, 2015	Jun. 28, 2015 Fair Value, Inputs, Level 2 [Member]
Cash and Cash Equivalents [Line Items]
Maturities period of certificates of deposit minimum			3 months
Maturities period of certificates of deposit maximum			3 years
Available-for-sale Securities, Current	$ 14.0	$ 14.5
Available-for-sale Securities, Noncurrent	$ 16.1	$ 17.2

Inventories (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
Summary of Inventories
Inventory (FIFO basis)	$ 44,645	$ 42,567
LIFO reserve	(5,561)	(5,539)
Net inventory	$ 39,084	$ 37,028

Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
Summary of Finite-Lived Intangible Assets [Line Items]
Finite-life intangible assets, Gross Carrying Amount	$ 14,085	$ 13,860
Finite-life intangible assets, Accumulated Amortization	(4,242)	(3,933)
Total finite-life intangible assets, Net	9,843	9,927
Indefinite-life intangible assets gross	1,227	1,227
Indefinite-life intangible assets, Accumulated Amortization	0	0
Indefinite-life intangible assets	1,227	1,227
Total Intangible Assets, Gross	15,312	15,087
Intangible assets, Accumulated Amortization	(4,242)	(3,933)
Total intangible assets, net	11,070	11,154
Customer Relationships [Member]
Summary of Finite-Lived Intangible Assets [Line Items]
Finite-life intangible assets, Gross Carrying Amount	9,948	9,723
Finite-life intangible assets, Accumulated Amortization	(1,837)	(1,697)
Total finite-life intangible assets, Net	8,111	8,026
Trademarks [Member]
Summary of Finite-Lived Intangible Assets [Line Items]
Finite-life intangible assets, Gross Carrying Amount	2,034	2,034
Finite-life intangible assets, Accumulated Amortization	(754)	(667)
Total finite-life intangible assets, Net	1,280	1,367
Trade secrets [Member]
Summary of Finite-Lived Intangible Assets [Line Items]
Finite-life intangible assets, Gross Carrying Amount	962	962
Finite-life intangible assets, Accumulated Amortization	(919)	(896)
Total finite-life intangible assets, Net	43	66
Carrier relationships [Member]
Summary of Finite-Lived Intangible Assets [Line Items]
Finite-life intangible assets, Gross Carrying Amount	800	800
Finite-life intangible assets, Accumulated Amortization	(395)	(337)
Total finite-life intangible assets, Net	405	463
Other finite-life intangible assets [Member]
Summary of Finite-Lived Intangible Assets [Line Items]
Finite-life intangible assets, Gross Carrying Amount	341	341
Finite-life intangible assets, Accumulated Amortization	(337)	(336)
Total finite-life intangible assets, Net	$ 4	$ 5

Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
Unrealized gain (loss) on:
Available-for-sale investments	$ 30	$ (25)
Post-retirement plan liability	(7)	(7)
Accumulated other comprehensive income (loss)	$ 23	$ (32)

Share Based Compensation (Details) (Performance-Based Restricted Stock [Member], USD $)	3 Months Ended
	Jun. 28, 2015
Performance-Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested at beginning of period (Shares)	53,580
Granted (Shares)	37,309
Vested (Shares)	(28,648)
Unvested at end of period (Shares)	62,241
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning Balance, Weighted average grant date fair value (usd per share)	$ 37.55
Granted, Weighted average grant date fair value (usd per share)	$ 40.89
Vested, Weighted average grant date fair value (usd per share)	$ 40.25
Ending Balance, Weighted average grant date fair value (usd per share)	$ 38.31

Share Based Compensation (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Mar. 29, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Fiscal Year Focus	2016
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 0	$ 0
Stock options exercised			9,333
Weighted average exercise price (usd per share)			$ 19.90
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of restricted stock to be issued minimum (shares)	0
Range of restricted stock to be issued maximum (shares)	44,446
Performance-Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	0.3	0.3
Vesting period	2 years
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 0.1	$ 0.1
Vesting period	1 year
Restricted stock awards outstanding (shares)	7,077
Restricted stock awards, weighted average exercise price (usd per share)	$ 34.61

Share Repurchase Program (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Mar. 29, 2015	May 29, 2014
Share Repurchase Program [Abstract]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased				300,000
Stock Repurchased During Period, Shares	13,850	39,170	59,602
Stock Repurchased During Period, Value	$ 0.6	$ 1.4	$ 2.2

Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 28, 2015	Jun. 29, 2014
Segment Reporting Information [Line Items]
Sales	$ 101,496	$ 98,036
Gross profit	20,735	18,496
Selling, general and administrative expenses	9,891	8,875
Operating income	10,844	9,621
Industrial [Member]
Segment Reporting Information [Line Items]
Sales	67,588	67,546
Gross profit	10,714	9,361
Selling, general and administrative expenses	5,199	5,099
Operating income	5,515	4,262
Water Treatment [Member]
Segment Reporting Information [Line Items]
Sales	33,908	30,490
Gross profit	10,021	9,135
Selling, general and administrative expenses	4,692	3,776
Operating income	$ 5,329	$ 5,359

Segment Information (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 28, 2015 Customer Segment
Segment Reporting [Abstract]
Number of reportable segments (segments)	2
Intersegment sales	$ 0
Number of operating segments aggregated (segments)	0
Number of customer representing 10 percent or more of revenue (customers)	0

Litigation, Commitments and Contingencies	3 Months Ended
Litigation, Commitments and Contingencies	Jun. 28, 2015
Commitments and Contingencies Disclosure [Abstract]
Litigation, Commitments and Contingencies	Litigation, Commitments and Contingencies Litigation — There are no material pending legal proceedings, other than ordinary routine litigation incidental to the business, to which we or any of our subsidiaries are a party or of which any of our property is the subject. Legal fees associated with such matters are expensed as incurred.

Basis of Presentation Basis of Presentation (Details)	3 Months Ended	12 Months Ended
Basis of Presentation Basis of Presentation (Details)	Jun. 28, 2015	Mar. 29, 2015
Basis of Presentation [Abstract]
Fiscal Period Duration	371 days	364 days

Inventories (Details Textual) (USD $)	3 Months Ended
Inventories (Details Textual) (USD $)	Jun. 28, 2015	Jun. 29, 2014	Mar. 29, 2015
Inventory Disclosure [Abstract]
Finished goods (LIFO basis)	$ 41,400,000		$ 39,000,000
Increase (decrease) in LIFO reserve	$ 0	$ 490,000

Goodwill and Intangible Assets (Details Textual) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2015	Mar. 29, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 11,750	$ 11,750