Income Taxes - Reconciliation of Provision for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Benefit from for income taxes at U.S. Federal statutory rate	$ (7,628)	$ (8,103)	$ (6,193)
State taxes	5,368	2,940	(824)
Differential in rates on foreign earnings	4,311	(1,396)	(4,880)
Non-deductible amortization expense	3,138	4,311	7,279
Change in valuation allowance	26,053	(996)	(1,104)
Change in liabilities for uncertain tax positions	(8,126)	(35,742)	1,495
Non-deductible stock-based compensation	1,665	981	1,974
Research and development tax credits	(841)	(5,044)	0
Non-deductible meals and entertainment	361	346	208
Adjustments related to tax positions taken during prior years	0	(1,154)	619
Tax-exempt investment income	0	(304)	(248)
Other	152	(580)	168
Total provision for (benefit from) income taxes	$ 24,453us-gaap_IncomeTaxExpenseBenefit	$ (44,741)us-gaap_IncomeTaxExpenseBenefit	$ (1,506)us-gaap_IncomeTaxExpenseBenefit

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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