Unaudited Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011
Cash flows from operating activities:
Net income	$ 70,460	$ 68,533
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	12,125	11,068
Purchase premium amortization on investments	2,018	467
Non-cash stock-based compensation	10,806	10,334
Income tax benefit associated with stock option exercises	926	3,269
Gain on sale of cost method investment	(3,126)	0
Excess tax benefit from stock-based compensation	(1,374)	(3,426)
Deferred income taxes	(1,602)	(1,516)
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	12,469	8,078
Inventories	(14,603)	(2,279)
Prepaid expenses and other assets	74	(5,813)
Accounts payable	(26,855)	(13,484)
Accrued employee compensation	(6,005)	(940)
Other accrued liabilities	(2,126)	(3,013)
Deferred revenue	(12,120)	(3,604)
Income taxes payable	(3,507)	(4,521)
Net cash provided by operating activities	37,560	63,153
Cash flows from investing activities:
Purchases of short-term investments	(308,787)	(188,329)
Proceeds from maturities of short-term investments	223,733	185,680
Purchase of property and equipment	(11,492)	(5,816)
Payments made in connection with business acquisitions, net of cash acquired	(28,625)	(37,509)
Net cash used in investing activities	(125,171)	(45,974)
Cash flows from financing activities:
Purchase and retirement of treasury stock	(815)	(899)
Proceeds from exercise of stock options	10,757	26,647
Proceeds from issuance of common stock under employee stock purchase plan	1,998	1,752
Excess tax benefit from stock-based compensation	1,374	3,426
Net cash provided by financing activities	13,314	30,926
Net (decrease) increase in cash and cash equivalents	(74,297)	48,105
Cash and cash equivalents, at beginning of period	208,898	126,173
Cash and cash equivalents, at end of period	$ 134,601	$ 174,278