Balance Sheet Components - Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Components
Reserves for refunds to insurance carriers	$ 17,210	$ 17,366	$ 9,410
Accrued charges for third-party testing	5,849	5,141
Testing and laboratory materials from suppliers	3,799	2,720
Marketing and corporate affairs	7,853	3,325
Legal, audit and consulting fees	11,758	4,189
Accrued shipping charges	969	1,604
Sales tax payable	2,230	1,723
Accrued third-party service fees	13,442	2,355
Clinical trials, studies, and other development	11,218	2,353
Operating lease liabilities, current portion	5,752	7,300
Fixed asset purchases	1,853	1,691
Other accrued interest	1,078	1,078
Other accrued expenses	10,342	9,562
Total other accrued liabilities	$ 93,353	$ 60,407