Income Taxes - Significant Components of The Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Accruals and prepaids	$ 12,904	$ 4,302
Deferred revenue	34,710	44,359
Net operating loss carryforwards	229,464	176,555
Stock-based Compensation	3,748	1,612
Investment tax and other credits	11,261	7,369
Gross deferred tax assets	292,087	234,197
Deferred tax liabilities:
Capitalized initial direct costs	27,539	16,640
Fixed asset depreciation	178,511	142,866
Deferred tax on investment in partnerships	276,183	184,240
Gross deferred tax liabilities	482,233	343,746
Net deferred tax liabilities	$ (190,146)	$ (109,549)