Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Sales taxes and VAT payable	$ 126,400	$ 111,592
Sales returns reserve (1)	104,001	0
Product warranty	45,605	87,882
Employee-related liabilities	33,916	33,266
Accrued co-op advertising and marketing development funds	30,435	30,408
Accrued manufacturing expense and freight	21,357	41,901
Sales taxes and VAT payable	20,121	21,340
Accrued sales and marketing	18,171	44,401
Accrued research and development	8,783	8,983
Inventory received but not billed	6,373	10,526
Accrued legal settlements and fees	2,821	36,693
Derivative liabilities	549	2,138
Other	18,702	23,007
Accrued liabilities	$ 437,234	$ 452,137