Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	$ 3,600,000
Period of increase in ownership	3 years
Unrealized tax benefits	$ 0	$ 0
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 79,700,000
Operating loss carryforwards expiration period	2024
Domestic Tax Authority [Member] | Expire in 2024 [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 45,700,000
Expired federal net operating losses indefinite	17,000,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 12,400,000