Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign

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

	Years Ended December 31,
	2018			2017			2016
United States	$	(259,787	)	$	(283,710	)	$	(337,449	)
Foreign	1,835			3,081			1,862
Total	$	(257,952	)	$	(280,629	)	$	(335,587	)

Schedule of Components of Income Tax Expense (Benefit)

 The provision for income taxes is comprised of the following (in thousands):

	Years Ended December 31,
	2018			2017			2016
Current:
Federal	$	—		$	—		$	—
State	191			25			42
Foreign	1,407			621			702
Total current	1,598			646			744
Deferred:
Federal	—			—			—
State	—			—			—
Foreign	(61		)	(10		)	(15		)
Total deferred	(61		)	(10		)	(15		)
Total provision for income taxes	$	1,537		$	636		$	729

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the U.S. federal statutory income tax rate to our effective tax rate is as follows (in thousands):

	Years Ended December 31,
	2018			2017			2016
Tax at federal statutory rate	$	(54,170	)	$	(95,414	)	$	(114,100	)
State taxes, net of federal effect	191			25			42
Impact on noncontrolling interest	3,725			6,347			19,264
Non-U.S. tax effect	960			(437		)	54
Nondeductible expenses	6,637			5,698			4,426
Stock-based compensation	3,892			4,854			4,243
U.S. tax reform impact	—			239,117			—
U.S. tax on foreign earnings	127			—			—
Change in valuation allowance	40,175			(159,554		)	86,800
Provision for income taxes	$	1,537		$	636		$	729

Schedule of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities consist of the following (in thousands): 

	December 31,
	2018			2017
Tax credits and NOLs	$	468,612		$	457,718
Depreciation and amortization	9,631			10,811
Deferred revenue	17,415			27,195
Accruals and reserves	14,103			17,163
Stock-based compensation	62,793			18,956
Derivative liability	—			33,200
Other items	24,834			16,218
Gross deferred tax assets	597,388			581,261
Valuation allowance	(566,442		)	(542,409		)
Net deferred tax assets	30,946			38,852
Investment in PPA entities	(21,587		)	(25,252		)
Debt issuance cost	(8,586		)	(12,827		)
Gross deferred tax liabilities	(30,173		)	(38,079		)
Net deferred tax asset	$	773		$	773

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible

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

	Years Ended December 31,
	2018			2017
Unrecognized tax benefits beginning balance	$	28,331		$	27,136
Gross decrease for tax positions of prior year	(468		)	—
Gross increase for tax positions of prior year	353			—
Gross increase for tax positions of current year	2,095			1,195
Unrecognized tax benefits end balance	$	30,311		$	28,331