Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of Income before Income Taxes

Income before provision for income taxes was as follows:

	Year Ended December 31,
	2015		2014		2013
	(in thousands)
United States	$	95,644	$	325,081	$	159,126
Foreign	46,241		24,288		11,948
Income before income taxes	$	141,885	$	349,369	$	171,074

Components of Provision for Income Taxes

The components of provision for income taxes for all periods presented were as follows:

	Year Ended December 31,
	2015			2014			2013
	(in thousands)
Current tax provision:
Federal	$	52,557		$	86,623		$	58,558
State	(1,576		)	9,866			15,154
Foreign	26,918			16,144			7,003
Total current	77,899			112,633			80,715
Deferred tax provision:
Federal	(37,669		)	(10,994		)	(18,930		)
State	(17,635		)	(17,794		)	(2,751		)
Foreign	(3,351		)	(1,275		)	(363		)
Total deferred	(58,655		)	(30,063		)	(22,044		)
Provision for income taxes	$	19,244		$	82,570		$	58,671

Reconciliation of Provision for Income Taxes

A reconciliation of the provision for income taxes, with the amount computed by applying the statutory Federal income tax rate to income before income taxes is as follows:

	Year Ended December 31,
	2015			2014			2013
	(in thousands)
Expected tax expense at U.S. Federal statutory rate of 35%	$	49,658		$	122,279		$	59,878
State income taxes, net of Federal income tax effect	4,783			13,274			8,053
R&D tax credit	(29,363		)	(18,655		)	(13,841		)
Release of tax reserves on previously unrecognized tax benefits	(13,438		)	(38,612		)	—
Foreign earnings at other than US rates	5,310			2,959			821
Other	2,294			1,325			3,760
Provision for income taxes	$	19,244		$	82,570		$	58,671

Deferred Tax Assets and Liabilities

The components of deferred tax assets and liabilities were as follows:

	As of December 31,
	2015			2014
	(in thousands)
Deferred tax assets (liabilities):
Stock-based compensation	$	131,339		$	100,397
Accruals and reserves	14,367			13,415
Depreciation and amortization	(43,204		)	(11,708		)
R&D credits	74,091			21,014
Other	3,980			(2,778		)
Total deferred tax assets	$	180,573		$	120,340

Summary of Changes in Unrecognized Tax Benefits

The aggregate changes in the Company’s total gross amount of unrecognized tax benefits are summarized as follows (in thousands):

Balance as of December 31, 2013	$	68,231
Decreases related to tax positions taken during prior periods	(39,015		)
Increases related to tax positions taken during the current period	11,174
Decreases related to settlements with taxing authorities	(5,578		)
Balance as of December 31, 2014	$	34,812
Increases related to tax positions taken during prior periods	1,960
Decreases related to tax positions taken during prior periods	(12,334		)
Increases related to tax positions taken during the current period	7,077
Decreases related to settlements with taxing authorities	(14,398		)
Balance as of December 31, 2015	$	17,117