Loans and Allowance for Loan Losses - Summary of Non Accrual Loan (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Receivables [Abstract]
Total nonaccrual loans	$ 61,635	$ 21,549	$ 26,484
Interest foregone quarter to date	623	403	1,121
Amount of foregone interest applied to principal in the quarter	52	115	53
Interest foregone life to date	3,358	1,634	2,744
Amount of foregone interest applied to principal life to date	$ 494	$ 819	$ 471
Percentage of nonaccrual loans to gross loan portfolio	5.00%	2.00%	2.00%