CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Oct. 30, 2011	Oct. 31, 2010
Operating activities
Consolidated net income	$ 16,305	$ 52,922
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	21,590	16,850
Amortization	5,211	3,457
Stock-based compensation expense	13,764	8,219
Non-cash interest cost on 2.5% convertible senior subordinated notes		742
Loss on sale or retirement of assets	220	0
Equity in losses of equity method investment	619	0
Gain on fair value remeasurement of equity investment	(5,429)	0
Changes in operating assets and liabilities:
Accounts receivable	3,159	(45,626)
Inventories	(16,617)	(24,692)
Other assets	(21,840)	(1,465)
Deferred income taxes	542	769
Accounts payable	6,705	9,760
Accrued compensation	458	3,556
Other accrued liabilities	2,665	(1,903)
Deferred revenue	(1,001)	8,659
Net cash provided by operating activities	26,351	31,248
Investing activities
Purchases of property, equipment and improvements	(33,464)	(25,700)
Proceeds from sale of property and equipment	32	0
Acquisition of controlling interest in subsidiary, net of cash acquired	(71,125)	0
Purchase of available for sale minority investment	0	(5,880)
Net cash used in investing activities	(104,557)	(31,580)
Financing activities
Proceeds from term loan	1,800
Repayments of long-term debt	(14,026)	(2,000)
Repayment of convertible notes	0	(29,581)
Proceeds from the issuance of shares under employee stock option and stock purchase plans, net of repurchase of unvested shares	3,707	9,817
Net cash used in financing activities	(8,519)	(21,764)
Net decrease in cash and cash equivalents	(86,725)	(22,096)
Cash and cash equivalents at beginning of period	314,765	207,024
Cash and cash equivalents at end of period	228,040	184,928
Supplemental disclosure of cash flow information
Cash paid for interest	1,408	3,177
Cash paid for taxes	$ 5,015	$ 697