Loans Held for Investment and Allowance for Loan Losses - Non-Accrual Loans, Loans Still Accruing and Past Due 90 Days or More and Restructured Loans (Detail) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Receivables [Abstract]
Non-accrual loans		$ 38,812	$ 24,325	$ 24,604
Loans still accruing and past due 90 days or more		289	0	15
Total	[1]	$ 39,101	$ 24,325	$ 24,619

[1] (1) With the adoption of ASU 2022-02, effective January 1, 2023, troubled debt restructuring ("TDR") accounting has been eliminated