Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Options
Computation Of Earnings Per Share Line Items
Shares not included in computing diluted earnings per share because effects were anti-dilutive	86,284	251,026
Restricted Stock
Computation Of Earnings Per Share Line Items
Shares not included in computing diluted earnings per share because effects were anti-dilutive		10,500
ESOP
Computation Of Earnings Per Share Line Items
Shares not included in computing diluted earnings per share because effects were anti-dilutive	154,410	117,248