Condensed Consolidated Balance Sheet Components - Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accrued royalty obligations	$ 350	$ 1,564
Accrued legal expenses	2,951	1,046
Accrued tax liabilities	3,362	3,050
Accrued professional services	3,094	3,464
Accrued clinical trials and studies	2,012	2,029
Purchases of property and equipment included in accrued expenses	281	2,424
Operating lease liabilities	7,307	7,140
Other	3,716	4,986
Total accrued expenses	$ 23,073	$ 25,703