Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Income tax, federal statutory rate	21.00%	21.00%	35.00%
California
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 88.3
Minimum Tax Credit Carryforward [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforwards	0.1
Federal Tax Authority [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	232.1
Net operating loss carryforwards, Without Expiration	91.4
Federal Tax Authority [Member] | Research and Development Tax Credit [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforwards	11.4
State Tax Authority [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	1.8
State Tax Authority [Member] | Research and Development Tax Credit [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	7.8
Foreign Tax Authority [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforwards	$ 1.2