Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
OPERATING ACTIVITIES
Net income	$ 58,723	$ 35,499	$ 20,461
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Depreciation and amortization	16,456	14,526	14,545
Net loss on disposal of property, plant and equipment	1,576	153	123
Gain on sales of assets held for sale	0	(250)	(323)
Gain on insurance recoveries	0	0	(94)
Stock-based compensation expense	3,609	3,497	3,295
Deferred income taxes	11,629	4,335	7,978
Pension contributions in excess of expense	(4,732)	(4,604)	(2,039)
Excess tax benefit from stock-based compensation	(4,968)	(1,887)	(854)
Contributions of employer stock to employee benefit plan	1,761	6,217	3,843
Other non-cash items	(3,489)	(1,211)	(2,634)
Changes in operating assets and liabilities:
Customer receivables	(9,938)	288	(7,546)
Inventories	(4,276)	(5,605)	(2,875)
Prepaid expenses and other assets	(4,585)	126	(1,236)
Accounts payable	723	5,113	5,869
Accrued compensation and related expenses	5,269	1,963	1,943
Income taxes payable	(1,791)	1,201	526
Marketing and other accrued expenses	5,811	(624)	(447)
Net Cash Provided by Operating Activities	71,778	58,737	40,535
INVESTING ACTIVITIES
Payments to acquire property, plant, and equipment	(28,685)	(20,015)	(7,903)
Proceeds from sales of property, plant, and equipment	846	22	81
Proceeds from sales of assets held for sale	0	1,250	1,644
Proceeds from insurance recoveries	0	0	94
Purchases of certificates of deposit	(46,750)	(40,750)	0
Proceeds from Maturities, Prepayments and Calls of Short-term Investments	38,250	5,250	0
Investment in promotional displays	(4,434)	(2,363)	(3,499)
Net Cash Used by Investing Activities	(40,773)	(56,606)	(9,583)
FINANCING ACTIVITIES
Payments of long-term debt	(1,547)	(1,309)	(4,516)
Proceeds from long-term debt	3,196	1,500	0
Excess tax benefit from stock-based compensation	4,968	1,887	854
Proceeds from issuance of common stock	8,114	14,268	15,330
Repurchase of common stock	(16,593)	(5,053)	(3,141)
Notes receivable, net	(4,221)	417	(750)
Net Cash Provided by Financing Activities	(6,083)	11,710	7,777
Net Increase in Cash And Cash Equivalents	24,922	13,841	38,729
Cash And Cash Equivalents, Beginning of Year	149,541	135,700
Cash And Cash Equivalents, End of Year	$ 174,463	$ 149,541	$ 135,700