Loans and Allowance for Loan Losses - Summary of Non Accrual Loan (Detail) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Receivables [Abstract]
Total nonaccrual loans	$ 81,539	$ 26,878	$ 26,484
Interest foregone quarter to date	1,202	379	1,121
Amount of foregone interest applied to principal in the quarter	8	116	53
Interest foregone year to date	1,734	615	2,152
Amount of foregone interest applied to principal in the year	57	219	254
Interest foregone life to date	4,171	1,809	2,744
Amount of foregone interest applied to principal life to date	$ 973	$ 847	$ 471
Percentage of nonaccrual loans to gross loan portfolio	6.00%	2.00%	2.00%