v3.26.1
DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS - Estimated Fair Values of Financial Instruments (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Assets:    
Cash and cash equivalents, Carrying Amount $ 4,178,852 $ 4,411,463
Cash and cash equivalents, Estimated Fair Value 4,178,852 4,411,463
Debt securities, available for sale 2,595,966 1,906,535
Debt securities, held to maturity 631,594 729,134
Debt securities, held to maturity, fair value 575,548 683,598
Loans held for sale 58,611 26,102
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Carrying Amount 17,792,583 16,600,758
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 17,656,866 16,307,551
FHLB, Federal Reserve Bank and other restricted stock, Carrying Amount 144,971 110,411
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 144,971 110,411
Derivatives 9,626 11,369
Liabilities:    
Deposits, Carrying Amount 21,732,897 20,778,704
Deposits, Estimated Fair Value 21,735,283 20,806,081
FHLB advances, Carrying Amount 2,059,163 1,325,068
FHLB advances, Estimated Fair Value 2,057,460 1,327,565
Other borrowings, Carrying Amount 99,278 99,208
Other borrowings, Estimated Fair Value 95,509 93,834
Subordinated debt, Carrying Amount 171,741 281,147
Subordinated debt, Estimated Fair Value 164,402 277,105
Derivative liabilities 14,443 15,799
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Assets:    
Cash and cash equivalents, Estimated Fair Value 4,178,852 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 18,170,236 17,482,736
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 2,294,474 1,668,722
Debt securities, held to maturity, fair value 397,337 426,981
Loans held for sale 2,528 1,851
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 1,654,795 1,612,997
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 144,971 110,411
Derivatives 9,533 11,325
Liabilities:    
Deposits, Estimated Fair Value 3,565,047 3,323,345
FHLB advances, Estimated Fair Value 2,057,460 1,327,565
Other borrowings, Estimated Fair Value 95,509 93,834
Subordinated debt, Estimated Fair Value 164,402 277,105
Derivative liabilities 14,443 15,799
Significant Unobservable Inputs (Level 3)    
Assets:    
Cash and cash equivalents, Estimated Fair Value 0 0
Debt securities, available for sale 301,492 237,813
Debt securities, held to maturity, fair value 178,211 256,617
Loans held for sale 56,083 24,251
Total loans and leases receivable, net of allowance for credit losses on loans and leases, Estimated Fair Value 16,002,071 14,694,554
FHLB, Federal Reserve Bank and other restricted stock, Estimated Fair Value 0 0
Derivatives 93 44
Liabilities:    
Deposits, Estimated Fair Value 0 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