Balance Sheet Components - Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities, Noncurrent
Financing obligations	$ 53,682	$ 55,355
Capital lease obligations, non-current portion	48,620	50,213
Deferred revenue, non-current portion	5,618	7,303
Deferred tax liability	1,012	20,446
Other liabilities	10,263	3,718
Total other liabilities	$ 119,195	$ 137,035