Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Income tax paid	$ 0	$ 0	$ 0
U.S. Federal
Income Taxes [Line Items]
Net operating loss carryforwards	193,200,000
Research and development tax credit	12,800,000
Foreign
Income Taxes [Line Items]
Net operating loss carryforwards	24,200,000
State and City
Income Taxes [Line Items]
Net operating loss carryforwards	63,500,000
Subject To Annual Limitations | U.S. Federal
Income Taxes [Line Items]
Net operating loss carryforwards	56,600,000
Not Subject To Annual Limitations | U.S. Federal
Income Taxes [Line Items]
Net operating loss carryforwards	156,500,000
Research and development tax credit	12,800,000
Not Subject To Annual Limitations | State and City
Income Taxes [Line Items]
Net operating loss carryforwards	$ 63,300,000