Nature of Operations and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2018	Sep. 05, 2018
Nature Of Operations [Abstract]
Sale and issuance of common stock, per share		$ 10.00
Number of shares sold under ESOP, as percentage		3.92%
Percent of outstanding common shares eligible to employee stock ownership plan		45.00%
Percent of outstanding common stock		55.00%
Deferred reorganization costs	$ 413