CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 25, 2014	Jan. 26, 2013
Cash flows from operating activities
Net income	$ 43,823	$ 28,690
Adjustments to reconcile net income to cash provided by (used for) operating activities
Gain on sale of investments	(282)	(2,866)
Impairment of business held for sale	1,149	0
Deferred income tax benefit	(2,929)	(745)
Restructuring	(115)	2,716
Provision for doubtful accounts	(2,494)	1,009
Depreciation and amortization	17,529	17,111
Stock-based compensation expense	7,371	8,198
Pension plan contributions	0	(3,480)
Change in receivables	4,865	2,457
Change in inventories	(15,166)	(12,355)
Change in other assets	2,980	(5,432)
Change in payables	2,865	(6,261)
Change in other liabilities	3,193	4,410
Net cash provided by operating activities	62,789	33,452
Cash flows from investing activities
Proceeds from disposals of assets	2,248	1,484
Capital expenditures	(23,078)	(21,792)
Purchases of investments	(40,796)	(36,353)
Proceeds from sales of investments	27,974	12,658
Acquisitions, net of cash acquired	(801)	(15,832)
Change in restricted cash	120	(6,937)
Net cash used for investing activities	(34,333)	(66,772)
Cash flows from financing activities
Payments on debt	(434)	(2,372)
Stock issued for stock and employee benefit plans	3,526	1,528
Excess tax benefit on stock option exercises	5,805	1,117
Purchases of common stock	(20,276)	(5,217)
Dividends paid	(7,375)	(2,119)
Net cash used for financing activities	(18,754)	(7,063)
Effect of exchange rate changes on cash and equivalents	(675)	(6)
Change in cash and equivalents	9,027	(40,389)
Cash and equivalents at beginning of period	131,085	152,370
Cash and equivalents at end of period	140,112	111,981
Supplemental disclosure of non-cash investing activities [Abstract]
Capital expenditures included in payables	$ 2,183	$ 0