Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss And Tax Credit Carryforward [Line Items]
Valuation allowance	$ 174,921,000	$ 81,127,000
Increase (decrease) in valuation allowance	93,700,000	46,500,000
Additional income taxes provided on undistributed foreign earnings	0
Undistributed foreign earnings	7,400,000
Cumulative unrecognized tax benefits	4,905,000	$ 3,351,000	$ 1,486,000
Unrecognized tax benefits that would impact effective tax rate	0
Federal
Operating Loss And Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 238,700,000
Operating loss carryforwards, expiration year	2020
Federal | Research and Development
Operating Loss And Tax Credit Carryforward [Line Items]
Research and development credits	$ 16,600,000
Research and development credits, expiration year	2032
State
Operating Loss And Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 167,600,000
Operating loss carryforwards, expiration year	2020
State | Research and Development
Operating Loss And Tax Credit Carryforward [Line Items]
Research and development credits	$ 13,400,000
Foreign | Research and Development
Operating Loss And Tax Credit Carryforward [Line Items]
Research and development credits	$ 1,100,000
Research and development credits, expiration year	2037