Loans Held for Investment and Allowance for Credit Losses on Loans - Transfers from Loans and Premises and Equipment to Other Real Estate Owned, Repossessed Assets and Other Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Noncash Investing and Financing Items [Abstract]
Other real estate owned	$ 12,651	$ 32,093	$ 3,941
Repossessed assets	844	1,418	1,473
Other assets		11,105
Total	$ 13,495	$ 44,616	$ 5,414