v3.26.1
FAIR VALUE - Estimated Fair Value and Carrying Value of Financial Instruments (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Assets:        
Available-for-sale debt securities (fair value) $ 4,668,697 $ 4,554,032    
Held To Maturity Securities Amortized 257,522 265,296    
Less: allowance for credit losses on held to maturity securities (641) (733)    
Loans held for investment 13,091,077 13,125,356    
Allowance for loan and lease losses (245,060) (249,037) $ (247,269) $ (243,942)
Loans held for investment, net of ACL 12,846,017 12,876,319    
Advances from the FHLB:        
Short-term 90,000 0    
Long-term advances from the FHLB 200,000 290,000    
Carrying Reported Amount Fair Value Disclosure [Member]        
Assets:        
Cash and due from banks and money market investments 550,899 658,599    
Available-for-sale debt securities (fair value) 4,668,697 4,554,032    
Held To Maturity Securities Amortized 257,522 265,296    
Less: allowance for credit losses on held to maturity securities (641) (733)    
Investment securities held to maturity, net of ACL 256,881 264,563    
Equity securities (amortized cost) 41,427 39,729    
Other equity securities 5,005 5,024    
Loans held for sale 12,805 16,697    
Loans held for investment 13,091,077 13,125,356    
Allowance for loan and lease losses (245,060) (249,037)    
Loans held for investment, net of ACL 12,846,017 12,876,319    
Mortgage servicing rights 22,880 23,288    
Derivative assets $ 350 $ 345    
Derivative Asset Statement Of Financial Position Extensible Enumeration Other Assets Other Assets    
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]        
Deposits $ 16,595,821 $ 16,670,143    
Advances from the FHLB:        
Short-term 90,000      
Derivative liabilities $ 162 $ 200    
Derivative Liability Statement Of Financial Position Extensible Enumeration Accrued Liabilities and Other Liabilities Accrued Liabilities and Other Liabilities    
Federal Home Loan Bank Stock $ 24,700 $ 24,700    
Estimate Of Fair Value Fair Value Disclosure [Member]        
Assets:        
Cash and due from banks and money market investments 550,899 658,599    
Available-for-sale debt securities (fair value) 4,668,697 4,554,032    
Investment securities held to maturity, net of ACL 253,485 262,055    
Equity securities (amortized cost) 41,427 39,729    
Other equity securities 5,005 5,024    
Loans held for sale 13,006 16,996    
Loans held for investment, net of ACL 12,773,439 12,806,115    
Mortgage servicing rights 40,485 40,874    
Derivative assets 350 345    
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]        
Deposits 16,600,047 16,675,488    
Advances from the FHLB:        
Short-term 90,001      
Derivative liabilities 162 200    
Estimate Of Fair Value Fair Value Disclosure [Member] | Fair Value Inputs Level 1 [Member]        
Assets:        
Cash and due from banks and money market investments 550,899 658,599    
Available-for-sale debt securities (fair value) 497,254 497,342    
Investment securities held to maturity, net of ACL 0 0    
Equity securities (amortized cost) 0 0    
Other equity securities 5,005 5,024    
Loans held for sale 0 0    
Loans held for investment, net of ACL 0 0    
Mortgage servicing rights 0 0    
Derivative assets 0 0    
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]        
Deposits 0 0    
Advances from the FHLB:        
Short-term 0      
Derivative liabilities 0 0    
Estimate Of Fair Value Fair Value Disclosure [Member] | Fair Value Inputs Level 2 [Member]        
Assets:        
Cash and due from banks and money market investments 0 0    
Available-for-sale debt securities (fair value) 4,166,721 4,051,804    
Investment securities held to maturity, net of ACL 171,353 178,815    
Equity securities (amortized cost) 41,427 39,729    
Other equity securities 0 0    
Loans held for sale 13,006 16,996    
Loans held for investment, net of ACL 0 0    
Mortgage servicing rights 0 0    
Derivative assets 350 345    
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]        
Deposits 16,600,047 16,675,488    
Advances from the FHLB:        
Short-term 90,001      
Derivative liabilities 162 200    
Estimate Of Fair Value Fair Value Disclosure [Member] | Fair Value Inputs Level 3 [Member]        
Assets:        
Cash and due from banks and money market investments 0 0    
Available-for-sale debt securities (fair value) 4,722 4,886    
Investment securities held to maturity, net of ACL 82,132 83,240    
Equity securities (amortized cost) 0 0    
Other equity securities 0 0    
Loans held for sale 0 0    
Loans held for investment, net of ACL 12,773,439 12,806,115    
Mortgage servicing rights 40,485 40,874    
Derivative assets 0 0    
Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract]        
Deposits 0 0    
Advances from the FHLB:        
Short-term 0      
Derivative liabilities $ 0 $ 0