Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Jan. 01, 2019
Lessee Lease Description [Line Items]
Net lease liabilities	$ 1,958	$ 1,958
Operating lease, right-of-use assets	$ 1,828	1,828
Lease expiration date	May 31, 2020
Seattle, Washington [Member]
Lessee Lease Description [Line Items]
Net lease liabilities	$ 1,200	1,200
Operating lease, right-of-use assets	$ 1,200	$ 1,200
Operating lease terms	87 months	87 months
Lease expiration date		Jul. 31, 2027
Operating lease rent starting date		May 01, 2020
Minimum [Member]
Lessee Lease Description [Line Items]
Operating lease terms	1 year	1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Operating lease terms	8 years	8 years
ASU 2016-02 [Member]
Lessee Lease Description [Line Items]
Net lease liabilities			$ 1,700
Operating lease, right-of-use assets			1,200
Deferred rent, de-recognized			$ (500)