LOANS HELD FOR INVESTMENT - Loan Portfolio Held for Investment (Parenthetical) (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, before Allowance for Credit Loss	$ 11,577,985	$ 11,552,825
Unaccreted fair value net purchase discounts	28,300	29,300
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Financing Receivable, before Allowance for Credit Loss	2,862,189	2,886,263
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member] \| Commercial loans secured by real estate [Member]
Financing Receivable, before Allowance for Credit Loss	$ 837,800	$ 838,500

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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+ Details