Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of income before provision for income taxes

Income (loss) before income taxes is as follows (in thousands):

	Year Ended December 31,
	2017		2016		2015
United States	$	35,213	$	26,440	$	(2,303	)
Foreign	32		148		314
Total	$	35,245	$	26,588	$	(1,989	)

Components of provision for (benefit from) income taxes

The components of the provision for (benefit from) income taxes are as follows (in thousands):

	December 31,
	2017			2016			2015
Federal:
Current	$	912		$	837		$	(23	)
Deferred	(2,884		)	7,306			(2,053		)
	(1,972		)	8,143			(2,076		)
State:
Current	3,937			188			768
Deferred	3,050			1,895			91
	6,987			2,083			859
Foreign:
Current	472			758			258
Deferred	(327		)	(302		)	(187		)
	145			456			71
Total income tax expense (benefit):
Current	5,321			1,783			1,003
Deferred	(161		)	8,899			(2,149		)
	$	5,160		$	10,682		$	(1,146	)

Reconciliation of actual income tax rate and statutory federal income tax rate

The Company’s actual tax expense differed from the statutory federal income tax rate, as follows:

	December 31,
	2017		2016		2015
Income tax expense at statutory rate	35.0	%	35.0	%	35.0	%
State income taxes	0.8		(2.8	)	142.6
Stock-based compensation	(3.2	)	(0.4	)	8.9
R&D tax credit	(4.3	)	(6.6	)	173.5
Non-deductible executive compensation	5.4		4.7		(116.5	)
Valuation allowance	6.4		7.4		(170.7	)
Uncertain tax benefit liability settlement	—		1.4		—
Tax reform	(25.2	)	—		—
Other	(0.3	)	1.5		(15.3	)
	14.6	%	40.2	%	57.5	%

Components of net deferred tax assets

The components of the net deferred tax assets as of December 31, 2017 and 2016 are as follows (in thousands):

	December 31,
	2017			2016
Deferred tax assets:
Net operating loss carryforwards	$	1,837		$	460
Reserves and other tax benefits	33,145			50,178
Tax credits	32,057			17,149
Deferred tax assets	67,039			67,787
Valuation allowance	(17,111		)	(9,998		)
Net deferred tax assets	49,928			57,789
Deferred tax liabilities:
Depreciation and amortization	(47,293		)	(77,455		)
Net deferred tax assets (liabilities)	$	2,635		$	(19,666	)

Reconciliation of beginning and ending amounts of unrecognized income tax benefits

A reconciliation of the beginning and ending amounts of unrecognized income tax benefits is as follows (in thousands):

	2017		2016			2015
Balance of unrecognized tax benefits at January 1	$	6,586	$	5,703		$	8,566
Additions for tax positions of prior years	1,393		—			—
Additions for tax positions related to current year	1,050		951			1,050
Reductions for tax positions of prior years	—		(68		)	(3,913		)
Balance of unrecognized tax benefits at December 31	$	9,029	$	6,586		$	5,703