Balance Sheet Components - Other Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Sep. 30, 2019	Apr. 30, 2019	Dec. 31, 2018	Aug. 31, 2017	Aug. 14, 2017	Aug. 08, 2017
Balance Sheet Components [Line Items]
Common stock, shares issued	78,652,000		78,005,000
Cost of revenues	$ 41,520	$ 41,605
Amortization of debt discount	121	$ 98
Noncurrent assets	12,093		$ 12,476
Evercord
Balance Sheet Components [Line Items]
Net collections	500
Credit loss expense	1,200
Evercord | Contingent consideration
Balance Sheet Components [Line Items]
Total consideration			$ 4,700
Noncurrent assets
Balance Sheet Components [Line Items]
Debt discount	0
Long-term Debt
Balance Sheet Components [Line Items]
Debt discount	900
2017 Term Loan
Balance Sheet Components [Line Items]
Common stock, shares issued					25,000		300,000	300,000
Debt instrument, fee amount								$ 2,400
Remaining borrowing capacity					$ 50,000	$ 50,000	$ 50,000		$ 25,000
Debt discount								$ 2,700
2017 Term Loan | Noncurrent assets
Balance Sheet Components [Line Items]
Debt instrument, fee amount							$ 1,200
Evercord | Contingent consideration
Balance Sheet Components [Line Items]
Accounts receivable	3,100
BGI | Sequencing products and services
Balance Sheet Components [Line Items]
Noncurrent assets	$ 10,000			$ 10,000