Unaudited Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating activities:
Net income (loss)	$ 18,706	$ (1,280)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Loss from sale of discontinued operations		7,674
Loss from discontinued operations		2,253
Depreciation and amortization of intangible assets	16,950	6,190
Stock-based compensation	6,637	4,488
Warrant-related stock-based compensation	4,286	1,932
Excess tax benefits from stock-based award activity	(20,882)
Deferred income taxes	(7,398)	2
Unrealized amortization of premium on investments, net	(335)	285
Amortization of debt origination costs	746
Accretion of debt discount	294
Loss on derivative instrument	4,274
Earn-out contingent liability adjustments		2,000
Gain on resolution of contingent liability		(1,500)
Other	(21)	(8)
Changes in operating assets and liabilities:
Accounts receivable	(907)	(882)
Other receivables	504	(1,118)
Prepaid expenses and other current assets	705	849
Deferred tax assets and other long-term assets	(612)	(150)
Accounts payable	(2,344)	5,981
Accrued expenses and other current and long-term liabilities	18,357	(13,660)
Net cash provided by operating activities of continuing operations	38,960	13,056
Investing activities:
Business acquisition, net of cash acquired	(279,386)
Purchases of property and equipment	(2,776)	(2,507)
Change in restricted cash	168	409
Proceeds from sales of investments	184,934
Proceeds from maturities of investments	32,125	83,141
Purchases of investments	(59,076)	(204,777)
Net cash used by investing activities of continuing operations	(124,011)	(123,734)
Financing activities:
Proceeds from loan, net of debt issuance costs of $2,343 and debt discount of $953	96,704
Repayment of debt	(25,504)
Excess tax benefits from stock-based award activity	20,882
Proceeds from stock option exercises	7,812	16,287
Proceeds from issuance of stock through employee stock purchase plan	601	377
Tax payments from shares withheld upon vesting of restricted stock units	(934)	(1,388)
Earn-out payments for business acquisitions		(423)
Repayment of capital lease obligation		(221)
Proceeds from sale of common stock		7,000
Net cash provided by financing activities of continuing operations	99,561	21,632
Discontinued operations:
Net cash used by operating activities of discontinued operations		(6,156)
Net cash used by investing activities of discontinued operations		(638)
Net cash used by discontinued operations		(6,794)
Net increase (decrease) in cash and cash equivalents	14,510	(95,840)
Cash and cash equivalents:
Beginning of period	81,897	155,645
End of period	96,407	59,805
Supplemental disclosure of non-cash financing activities:
Contingent earn-out consideration from acquisition		$ (2,000)