v3.26.1
DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS - Estimated Fair Values of Financial Instruments (Detail) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Assets:    
Cash and cash equivalents, Carrying Amount $ 4,798,204 $ 4,411,463
Cash and cash equivalents, Estimated Fair Value 4,798,204 4,411,463
Debt securities, available for sale 1,961,852 1,906,535
Debt securities, held to maturity 663,545 729,134
Debt securities, held to maturity, fair value 608,462 683,598
Loans held for sale 20,282 26,102
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Carrying Amount 17,210,302 16,600,758
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 16,965,491 16,307,551
FHLB, Federal Reserve Bank and other restricted stock, Carrying Amount 117,880 110,411
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 117,880 110,411
Derivatives 10,363 11,369
Liabilities:    
Deposits, Carrying Amount 21,592,645 20,778,704
Deposits, Estimated Fair Value 21,600,454 20,806,081
Federal funds purchased 70,000 0
Federal funds purchased, Estimated Fair Value 70,000  
FHLB advances, Carrying Amount 1,561,655 1,325,068
FHLB advances, Estimated Fair Value 1,597,424 1,327,565
Other borrowings, Carrying Amount 99,243 99,208
Other borrowings, Estimated Fair Value 96,760 93,834
Subordinated debt, Carrying Amount 171,614 281,147
Subordinated debt, Estimated Fair Value 167,648 277,105
Derivative liabilities 14,942 15,799
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Assets:    
Cash and cash equivalents, Estimated Fair Value 4,798,204 4,411,463
Debt securities, available for sale 0 0
Debt securities, held to maturity, fair value 0 0
Loans held for sale 0 0
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 0 0
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 0 0
Derivatives 0 0
Liabilities:    
Deposits, Estimated Fair Value 18,172,386 17,482,736
Federal funds purchased, Estimated Fair Value 0  
FHLB advances, Estimated Fair Value 0 0
Other borrowings, Estimated Fair Value 0 0
Subordinated debt, Estimated Fair Value 0 0
Derivative liabilities 0 0
Significant Other Observable Inputs (Level 2)    
Assets:    
Cash and cash equivalents, Estimated Fair Value 0 0
Debt securities, available for sale 1,686,146 1,668,722
Debt securities, held to maturity, fair value 392,958 426,981
Loans held for sale 1,767 1,851
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 1,758,685 1,612,997
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 117,880 110,411
Derivatives 10,310 11,325
Liabilities:    
Deposits, Estimated Fair Value 3,428,068 3,323,345
Federal funds purchased, Estimated Fair Value 70,000  
FHLB advances, Estimated Fair Value 1,597,424 1,327,565
Other borrowings, Estimated Fair Value 96,760 93,834
Subordinated debt, Estimated Fair Value 167,648 277,105
Derivative liabilities 14,942 15,799
Significant Unobservable Inputs (Level 3)    
Assets:    
Cash and cash equivalents, Estimated Fair Value 0 0
Debt securities, available for sale 275,706 237,813
Debt securities, held to maturity, fair value 215,504 256,617
Loans held for sale 18,515 24,251
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 15,206,806 14,694,554
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 0 0
Derivatives 53 44
Liabilities:    
Deposits, Estimated Fair Value 0 0
Federal funds purchased, Estimated Fair Value 0  
FHLB advances, Estimated Fair Value 0 0
Other borrowings, Estimated Fair Value 0 0
Subordinated debt, Estimated Fair Value 0 0
Derivative liabilities $ 0 $ 0