INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2018

For financial reporting purposes, income (loss) before income taxes includes the following components (in thousands):



	Years ended December 31,
	2018			2017			2016
United States	$	(219,585	)	$	(48,039	)	$	20,974
Foreign	(369		)	305			(429		)
Total income (loss) before income taxes	$	(219,954	)	$	(47,734	)	$	20,545

Schedule of provision (benefit) for income taxes

The provision (benefit) for income taxes for 2018, 2017 and 2016 consists of the following (in thousands):



	Years ended December 31,
	2018			2017			2016
Current:
Federal	$	(57	)	$	365		$	280
State	(141		)	280			1,264
Foreign	44			57			34
Total current	(154		)	702			1,578
Deferred:
Federal	(1,583		)	56,350			7,311
State	(645		)	7,146			410
Foreign	(2		)	(10		)	(2		)
Total deferred	(2,230		)	63,486			7,719
Total provision (benefit) for income taxes	$	(2,384	)	$	64,188		$	9,297

Schedule of components of deferred tax assets and liabilities

The components of our deferred tax assets and liabilities as of December 31, 2018 and 2017 are as follows (in thousands):



	December 31,
	2018			2017
Deferred tax assets:
Net operating loss carryforwards	$	79,820		$	29,350
Research and development tax credits	15,382			12,653
Accrued expenses	7,898			10,672
Reserves and other	5,345			1,480
Basis difference in investments	4,857			1,636
Fixed and intangible assets	2,493			8,068
Other tax credits	206			220
Gross deferred tax assets	116,001			64,079
Valuation allowance	(114,523		)	(63,278		)
Total deferred tax assets	1,478			801
Deferred tax liabilities:
Prepaid expenses	(880		)	(788		)
Goodwill	(489		)	(261		)
Fixed assets	—			—
Total deferred tax liabilities	(1,369		)	(1,049		)
Total deferred tax assets (liabilities), net	$	109		$	(248	)

Schedule of difference in income tax provision from amount computed by applying U.S. federal income tax rate of 35% to loss before income taxes

The provision (benefit) for income taxes for 2018, 2017 and 2016 differ from the amounts computed by applying the U.S. federal income tax rate of 21% for 2018 and 35% for 2017 and 2016 to income (loss) before income taxes for the following reasons (in thousands):



	Year ended December 31,
	2018			2017			2016
U.S. federal income tax provision (benefit) at statutory rate	$	(46,190	)	$	(16,707	)	$	7,191
State income tax expense, net of federal benefit	(8,289		)	(2,480		)	1,232
Research and development credit	(1,734		)	(1,696		)	(1,078		)
Stock based compensation expense	(1,260		)	164			674
Other	1,652			581			110
Gain on subsidiary stock	2,192			—			—
Reduction in federal rate	—			25,287			—
Change in valuation allowance	51,245			59,039			1,168
Total provision (benefit) for income taxes	$	(2,384	)	$	64,188		$	9,297

Schedule of reconciliation of beginning and ending tax contingencies, excluding interest and penalties

A reconciliation of the beginning and ending unrecognized tax benefits, excluding interest and penalties, as of December 31, 2018, 2017 and 2016 is as follows (in thousands):



	Year ended December 31,
	2018			2017			2016
Beginning balance	$	6,964		$	7,333		$	4,753
Additions for tax positions related to the current year	1,013			881			1,112
Additions (reductions) for tax positions taken in prior years	332			230			1,468
Reduction for tax positions settled by utilizing tax attributes	(335		)	(1,480		)	—
Ending balance	$	7,974		$	6,964		$	7,333