Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income (loss)	$ (21,698)	$ 23,006
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Gain on investments carried at fair value, net	0	(118)
Provision for (recovery of) doubtful accounts and returns	(1,039)	1,934
Provision for (reduction of) warranty	1,550	(1,305)
Inventory write downs	5,810	3,164
Loss on disposal of fixed assets	377	51
Depreciation	13,030	12,383
Amortization of intangible assets	28,358	15,958
Amortization, other	239	612
Deferred income taxes	(10,648)	6,925
Stock-based compensation	7,813	9,914
Excess tax benefits from stock-based compensation	(12)	(872)
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable	46,911	20,112
Inventories	4,767	(5,660)
Deferred costs	13,246	15,889
Prepaid expenses	546	56
Other current assets	(275)	545
Accounts payable	(4,319)	(16,461)
Accrued expenses	24,139	(10,118)
Accrued compensation and related expenses	(5,642)	(20,062)
Deferred revenues	(35,952)	(39,079)
Income taxes receivable	(8,470)	1,617
Income taxes payable	2,606	1,711
Total adjustments	82,285	(2,804)
Net cash provided by (used in) operating activities	61,337	20,202
Cash flows from investing activities:
Proceeds from sales and maturities of investments	0	92,975
Purchase of acquired business, net of cash acquired	0	(161,953)
Purchases of property and equipment	(12,039)	(14,060)
Net cash provided by (used in) investing activities	(12,039)	(83,038)
Cash flows from financing activities:
Proceeds from issuances of common stock	1,265	10,892
Payments of net share-settled payroll taxes related to equity awards	(1,244)	(2,914)
Excess tax benefits from stock-based compensation	12	872
Net cash provided by (used in) financing activities	33	8,850
Effect of exchange rate changes on cash	187	(558)
Net change in cash and cash equivalents	49,518	(54,544)
Cash and cash equivalents, beginning of period	220,938	277,259
Cash and cash equivalents, end of period	$ 270,456	$ 222,715