Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Oct. 02, 2011	Sep. 26, 2010
Cash flows from operating activities:
Net income	$ 61,080	$ 55,435
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,047	15,342
Stock-based compensation	17,687	18,592
Amortization of acquisition-related intangible assets	2,312	2,311
Deferred income taxes	509	5,147
Net gains on investment securities	(817)	(1,728)
Other non-cash items	2,341	92
Changes in operating assets and liabilities:
Accounts receivable	(16,625)	(13,155)
Inventories	3,423	(5,544)
Other assets	(652)	543
Accounts payable	2,137	(6,376)
Accrued compensation	(3,636)	(718)
Accrued taxes	156	(8,692)
Deferred revenue	(1,453)	(733)
Other liabilities	1,310	(3,234)
Net cash provided by operating activities	81,819	57,282
Cash flows from investing activities:
Purchases of available-for-sale securities	(242,274)	(47,920)
Proceeds from sales and maturities of available-for-sale securities	160,542	107,165
Proceeds from disposition of trading securities		23,800
Distributions from other investment securities		329
Purchases of property and equipment	(18,202)	(9,692)
Net cash provided by (used in) investing activities	(99,934)	73,682
Cash flows from financing activities:
Proceeds from issuance of common stock under stock-based awards	9,959	7,757
Excess tax benefits from stock-based awards	539	1,059
Minimum tax withholding paid on behalf of employees for restricted stock units	(5,363)	(5,937)
Purchases of treasury stock	(60,146)	(124,000)
Net cash used in financing activities	(55,011)	(121,121)
Net increase (decrease) in cash and cash equivalents	(73,126)	9,843
Cash and cash equivalents at beginning of period	147,780	190,308
Cash and cash equivalents at end of period	$ 74,654	$ 200,151