Balance Sheet Components - Other Accured Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Balance Sheet Components
Reserves for refunds to insurance carriers	$ 10,978	$ 7,535
Accrued charges for outsourced testing	5,998	3,261
Testing and laboratory materials from suppliers	1,203	543
Other accrued expenses	3,823	4,521
Marketing and corporate affairs	807	202
Legal, audit and consulting fees	394	180
Accrued shipping charges	459	467
Sales tax payable	192	459
Accrued specimen service fees	714	469
Accrued rent	637	195
Clinical trials and studies	407	388
Leasehold improvement projects in progress		1,659
Total other accrued liabilities	$ 25,612	$ 19,879