Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands		Dec. 31, 2018		Dec. 31, 2017
Deferred tax assets
Loss carryforwards		$ 370,120	[1]	$ 218,420
Tax credits		94,359	[2]	58,616
Accrued expenses		43,213		23,752
Pension plan benefits expense		18,086		18,262
Warranty reserves		13,470		11,170
Depreciation and amortization		5,709		5,736
Equity compensation		5,390		5,352
Inventory valuation		1,415		2,554
Deferred tax asset, deferred revenue		9,062		2,431
Other deferred tax assets, net		11,319		16,606
Total deferred tax assets		572,143		362,899
Valuation allowance		(323,822)	[1]	(285,784)
Total deferred tax assets, net of valuation allowance		248,321		77,115
Deferred tax liabilities
Depreciation and amortization		(178,358)		(23,135)
Tax effect of accumulated translation		0		(303)
Other deferred tax liabilities, net		(6,676)		(5,231)
Total deferred tax liabilities		(185,034)		(28,669)
Net deferred tax assets		63,287		$ 48,446
Deferred tax assets, tax credit carryforwards, general business	[2]	31,200
Deferred tax assets, tax credit carryforwards, alternative minimum tax	[2]	1,600
Deferred tax assets, tax credit carryforwards, foreign	[2]	50,400
Deferred tax assets, tax credit carryforwards, other	[2]	35,100
U.S. federal
Deferred tax liabilities
Loss carryforwards by Jurisdiction	[1]	350,700
LUXEMBOURG
Deferred tax liabilities
Loss carryforwards by Jurisdiction	[1]	$ 936,700

[1] For tax return purposes at December 31, 2018, we had U.S. federal loss carryforwards of $350.7 million which begin to expire in the year 2019. At December 31, 2018, we have net operating loss carryforwards in Luxembourg of $936.7 million, the majority of which can be carried forward indefinitely, offset by a full valuation allowance. The remaining portion of the loss carryforwards are composed primarily of losses in various other state and foreign jurisdictions. The majority of these losses can be carried forward indefinitely. At December 31, 2018, there was a valuation allowance of $323.8 million primarily associated with foreign loss carryforwards and foreign tax credit carryforwards (discussed below).

[2] For tax return purposes at December 31, 2018, we had: (1) U.S. general business credits of $31.2 million, which begin to expire in 2022; (2) U.S. alternative minimum tax credits of $1.6 million that can be carried forward indefinitely; (3) U.S. foreign tax credits of $50.4 million, which begin to expire in 2024; and (4) state tax credits of $35.1 million, which begin to expire in 2019.