Noninterest Income and Expense - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income and Expenses [Abstract]
Mortgage loan servicing fees, net of change in fair value of mortgage loan servicing rights	$ 106	$ 1,892	$ 1,358