Balance Sheet Components - Schedule of Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued Liabilities Current [Abstract]
Accounts payable	$ 55,298	$ 56,413
Accrued royalty expense	6,182	17,165
Accrued inventory	22,857	2,382
Accrued payroll and related expenses	7,195	8,699
Accrued cost of revenue	15,628	12,210
Accrued payments to content publishers	28,815	24,037
Taxes and related liabilities	1,135	1,463
Customer prepayments	2,951	545
Other accrued expenses	7,194	5,843
Total Accounts Payable and Accrued Liabilities	$ 147,255	$ 128,757