Leases - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Leases [Abstract]
Operating lease term	5 years		5 years
Operating lease ROU assets	$ 5,052,000		$ 5,052,000		$ 6,254,000
Operating lease liabilities	7,324,000		7,324,000
Cash paid for lease liabilities for operating leases	700,000		2,000,000
Right-of-use assets obtained in exchange for operating lease obligations	0		0
Operating lease obligations	0		0
Sublease income	$ 100,000	$ 0	$ 200,000	$ 0
Weighted average remaining operating lease term	3 years 6 months 18 days		3 years 6 months 18 days
Weighted average discount rate	8.59%		8.59%