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Restructuring - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 28, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2020
Restructuring Cost And Reserve [Line Items]
Percent of reduction in headcount of employees	30.00%
Restructuring Charges		$ 1,492,000	$ 0	$ 0
Cash payments		1,299,000
Scenario Forecast [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring liabilities expected to pay					$ 193,000
Severance And Other Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring Charges		$ 1,492,000