Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets (liabilities):
Stock-based compensation	$ 188,458	$ 131,339
Accruals and reserves	29,231	14,367
Depreciation and amortization	(93,760)	(43,204)
R&D credits	107,283	74,091
Other	(2,363)
Other		3,980
Gross deferred tax assets	228,849	180,573
Valuation allowance	(1,601)	0
Net deferred tax assets	$ 227,248	$ 180,573