Recently Issued Accounting Literature - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset	$ 4,663
Lease liability	$ 4,993
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset		$ 5,058
Lease liability		$ 5,428