Income Taxes (Tables)

12 Months Ended

Dec. 31, 2013

Income Tax Disclosure [Abstract]

Schedule of Income before Income Taxes

Income before provision for income taxes was as follows:

	Year Ended December 31,
	2013		2012		2011
	(in thousands)
United States	$	159,126	$	27,885	$	359,786
Foreign	11,948		2,595		(264		)
Income before income taxes	$	171,074	$	30,480	$	359,522

Components of Provision for Income Taxes

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

	Year Ended December 31,
	2013			2012			2011
	(in thousands)
Current tax provision:
Federal	$	58,558		$	34,387		$	123,406
State	15,154			7,850			28,657
Foreign	7,003			1,162			(70		)
Total current	80,715			43,399			151,993
Deferred tax provision:
Federal	(18,930		)	(26,903		)	(14,008		)
State	(2,751		)	(3,168		)	(4,589		)
Foreign	(363		)	—			—
Total deferred	(22,044		)	(30,071		)	(18,597		)
Provision for income taxes	$	58,671		$	13,328		$	133,396

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,
	2013			2012			2011
	(in thousands)
Expected tax expense at U.S. federal statutory rate of 35%	$	59,878		$	10,667		$	125,833
State income taxes, net of Federal income tax effect	8,053			2,914			15,042
R&D tax credit	(13,841		)	(1,803		)	(8,365		)
Other	4,581			1,550			886
Provision for income taxes	$	58,671		$	13,328		$	133,396

Deferred Tax Assets and Liabilities

	As of December 31,
	2013			2012
	(in thousands)
Deferred tax assets (liabilities):
Stock-based compensation	$	69,201		$	66,827
Accruals and reserves	13,022			11,155
Depreciation and amortization	(11,159		)	(18,356		)
R&D credits	19,196			8,480
Other	824			(244		)
Total deferred tax assets	91,084			67,862
Valuation allowance	(481		)	—
Net deferred tax assets	$	90,603		$	67,862

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, 2011	$	28,133
Increases related to tax positions taken during prior periods	8,487
Decreases related to tax positions taken during prior periods	(320		)
Increases related to tax positions taken during the current period	7,037
Balance as of December 31, 2012	$	43,337
Increases related to tax positions taken during prior periods	4
Decreases related to tax positions taken during prior periods	(25		)
Increases related to tax positions taken during the current period	24,915
Balance as of December 31, 2013	$	68,231