LOANS HELD FOR INVESTMENT - Additional Information I (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 13,091,077	$ 13,125,356
Asset Pledged as Collateral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,700,000	5,700,000
Asset Pledged as Collateral [Member] \| Time Deposits [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	107,600	111,200
Asset Pledged as Collateral [Member] \| Uninsured Portion Of Government Deposits [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	125,300	126,100
Asset Pledged as Collateral [Member] \| Federal Home Loan Bank Borrowings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,100,000	2,100,000
Asset Pledged as Collateral [Member] \| Federal Reserve Bank Advances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,400,000	3,400,000
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 2,914,898	$ 2,908,302