Balance Sheet Components - Schedule of Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts Payable And Accrued Liabilities Current [Abstract]
Accounts payable	$ 44,622	$ 56,576
Accrued royalty expense	5,024	7,939
Accrued inventory	7,566	6,008
Accrued payroll and related expenses	8,228	12,217
Accrued cost of revenue	17,658	22,830
Accrued payments to content publishers	39,576	32,463
Operating lease liability, current	14,208
Taxes and related liabilities	331	1,314
Customer prepayments	2,700	3,124
Other accrued expenses	7,010	6,091
Total Accounts Payable and Accrued Liabilities	$ 146,923	$ 148,562