Balance Sheet Components - Other Assets (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 30, 2016	Sep. 30, 2017	Sep. 30, 2017	Aug. 14, 2017	Aug. 08, 2017	Dec. 31, 2016
Balance Sheet Components [Line Items]
Agreement term	4 years
Total consideration	$ 3,200
Deferred costs included in other long-term assets		$ 2,000	$ 2,000			$ 2,600
Amortization of deferred costs		$ 200	$ 600
Common stock, shares issued		53,708,000	53,708,000			52,665,000
Noncurrent assets		$ 4,057	$ 4,057			$ 3,934
Debt discount		600	600
2017 Term Loan
Balance Sheet Components [Line Items]
Common stock, shares issued				300,000
Debt instrument, fee amount					$ 2,400
Remaining borrowing capacity					25,000
2017 Term Loan | Direct reduction from outstanding debt balance
Balance Sheet Components [Line Items]
Debt instrument, fee amount		$ 1,800	$ 1,800		1,800
2017 Term Loan | Noncurrent assets
Balance Sheet Components [Line Items]
Debt instrument, fee amount					$ 600