Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss	$ 1,232,399	$ 1,250,642
Tax credit carryforwards	367,402	315,535
Property and equipment	22	0
Intangible assets	34,938	14,673
Deferred revenues	31,205	9,341
Stock-based compensation	110,446	93,404
Inventories	4,705	5,913
Accrued expenses	23,078	27,236
Currency translation adjustment	0	222
Unrealized loss	5	0
Construction financing lease obligation	177,735	176,250
Gross deferred tax assets	1,981,935	1,893,216
Valuation allowance	(1,731,186)	(1,716,349)
Total deferred tax assets	250,749	176,867
Deferred tax liabilities:
Property and equipment	(169,089)	(175,424)
Acquired intangibles	(134,063)	(110,439)
Deferred revenue	(73,357)	0
Unrealized gain	(7,967)	(1,088)
Net deferred tax liabilities	$ (133,727)	$ (110,084)