Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income (loss)	$ 8,779	$ (4,335)	$ (24,139)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Amortization of intangibles	30,420	17,425	11,904
Depreciation	13,867	9,990	8,655
Stock-based compensation	20,913	15,539	10,579
Net loss on disposal of fixed assets	671	162	198
Deferred income taxes	(2,316)	(1,732)	11,818
Allowance for doubtful accounts	2,123	734	(3,534)
Other non-cash adjustments, net	801	1,529	2,594
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	(10,365)	(20,478)	8,960
Inventories	(12,652)	(11,979)	7,726
Prepaid expenses and other assets	7,924	(5,445)	(2,313)
Accounts payable	4,750	(3,080)	5,735
Deferred revenue	(13,470)	5,086	2,072
Income taxes payable	(6,843)	11,017	1,389
Accrued excess facility costs	(327)	(2,412)	(6,044)
Accrued and other liabilities	902	5,545	(24,512)
Net cash provided by operating activities	45,177	17,566	11,088
Cash flows from investing activities:
Purchases of investments	(107,544)	(51,457)	(129,202)
Proceeds from maturities of investments	28,733	80,961	130,641
Proceeds from sales of investments	30,999	63,269	27,240
Acquisition of property and equipment	(17,269)	(35,624)	(8,086)
Other acquisitions	(250)	(250)	(452)
Net cash used in investing activities	(65,331)	(96,355)	(42,912)
Cash flows from financing activities:
Proceeds from lease financing liability		18,833
Proceeds from issuance of common stock, net	12,701	3,859	4,243
Excess tax benefits from stock-based compensation	1,955	271
Net cash provided by financing activities	14,656	22,963	4,243
Effect of exchange rate changes on cash and cash equivalents	(52)	(118)	167
Net decrease in cash and cash equivalents	(5,550)	(55,944)	(27,414)
Cash and cash equivalents at beginning of period	96,533	152,477	179,891
Cash and cash equivalents at end of period	90,983	96,533	152,477
Supplemental disclosures of cash flow information:
Income tax payments, net	7,597	1,427	2,391
Non-cash investing and financing activities:
Financing liability for construction in progress			6,908
Acquisition of Scopus [Member]
Cash flows from investing activities:
Net of cash acquired from acquisition			(63,053)
Acquisition of Omneon [Member]
Cash flows from investing activities:
Net of cash acquired from acquisition		(153,254)
Non-cash investing and financing activities:
Issuance of restricted common stock for acquisition		95,938
Fair value of vested portion of stock options and restricted stock units assumed in connection with the Omneon acquisition		2,125
Acquisition of Rhozet [Member]
Non-cash investing and financing activities:
Issuance of restricted common stock for acquisition			$ 1,870