v3.26.1
Fair Value - Summary of Carrying and Fair Value Information of Financial Instruments (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Assets    
Cash and due from banks $ 1,547,967 $ 1,747,511
Federal funds sold 209 217
Held to maturity securities 10,687,015 9,433,365
Loans held for sale 21,925 14,155
Loans held for investment 23,832,909 20,486,415
Other real estate owned 13,257 13,296
Liabilities    
Noninterest-bearing 10,580,920 9,467,911
Interest-bearing 22,051,836 19,014,573
Other borrowings 2,200,000 1,950,000
Securities sold under repurchase agreements 176,099 201,216
Subordinated notes and junior subordinated debentures 76,186  
Carrying Amount [Member]    
Assets    
Cash and due from banks 1,547,967 1,747,511
Federal funds sold 209 217
Held to maturity securities 11,595,457 10,275,228
Loans held for sale 21,925 14,155
Loans held for investment, net of allowance 23,449,069 20,152,673
Loans held for investment 1,433,152 1,304,798
Other real estate owned 13,257 13,296
Liabilities    
Noninterest-bearing 10,580,920 9,467,911
Interest-bearing 22,051,836 19,014,573
Other borrowings 2,200,000 1,950,000
Securities sold under repurchase agreements 176,099 201,216
Subordinated notes and junior subordinated debentures 76,186  
Estimated Fair Value [Member]    
Assets    
Cash and due from banks 1,547,967 1,747,511
Federal funds sold 209 217
Held to maturity securities 10,687,015 9,433,365
Loans held for sale 21,925 14,155
Loans held for investment, net of allowance 22,645,809 19,342,602
Loans held for investment 1,433,152 1,304,798
Other real estate owned 13,257 13,296
Liabilities    
Noninterest-bearing 10,580,920 9,467,911
Interest-bearing 22,038,251 19,001,946
Other borrowings 2,200,000 1,950,000
Securities sold under repurchase agreements 176,099 201,216
Subordinated notes and junior subordinated debentures 76,186  
Estimated Fair Value [Member] | Level 1 [Member]    
Assets    
Cash and due from banks 1,547,967 1,747,511
Federal funds sold 209 217
Estimated Fair Value [Member] | Level 2 [Member]    
Assets    
Held to maturity securities 10,687,015 9,433,365
Loans held for sale 21,925 14,155
Loans held for investment 1,433,152 1,304,798
Other real estate owned 13,257 13,296
Liabilities    
Noninterest-bearing 10,580,920 9,467,911
Interest-bearing 22,038,251 19,001,946
Other borrowings 2,200,000 1,950,000
Securities sold under repurchase agreements 176,099 201,216
Subordinated notes and junior subordinated debentures 76,186  
Estimated Fair Value [Member] | Level 3 [Member]    
Assets    
Loans held for investment, net of allowance $ 22,645,809 $ 19,342,602