Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income (loss)	$ (16,107)	$ 6,430
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	49,654	45,592
Amortization of purchased intangibles	11,335	15,878
Amortization of debt issuance costs	52
Provision for doubtful accounts		800
Write-down of excess and obsolete inventories	5,625	5,297
Stock-based compensation	53,300	66,256
Excess tax benefits from stock-based compensation	(780)	(9,587)
Loss on disposal of property and equipment	3,658	3,502
Net gain on sale of discontinued operations	(459)
Changes in assets and liabilities, net of effects of acquisitions:
Trade receivables	21,857	20,435
Inventories	(13,346)	(13,858)
Deferred taxes	2,058	(12,947)
Prepaid expenses and other assets	(18,915)	4,188
Accounts payable	(1,118)	(31,552)
Taxes payable	(4,006)	1,032
Other accrued liabilities and deferred revenue	24,661	19,958
Net cash provided by operating activities	117,469	121,424
Cash flows from investing activities:
Purchases of property and equipment	(41,793)	(51,979)
Purchases of investments	(200,945)	(212,377)
Proceeds from sale of investments	21,802	37,794
Proceeds from maturity of investments	185,634	178,162
Net cash received from sale of discontinued operations	556
Net cash paid in purchase acquisitions	(7,974)	(4,583)
Net cash used in investing activities	(42,720)	(52,983)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee option and stock purchase plans	23,326	24,362
Proceeds from debt, net of debt issuance costs	247,582
Purchase and retirement of common stock	(110,816)	(62,073)
Excess tax benefits from stock-based compensation	780	9,587
Net cash provided by (used in) financing activities	160,872	(28,124)
Net increase in cash and cash equivalents	235,621	40,317
Cash and cash equivalents, beginning of period	477,073	375,441
Cash and cash equivalents, end of period	$ 712,694	$ 415,758