Fair Values of Assets and Liabilities - Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Financial Assets:
Interest-bearing deposits with banks	$ 4,409,753	$ 2,084,323
Available-for-sale securities	4,141,482	3,502,915
Held-to-maturity securities	2,910,550	3,215,468
Equity securities with readily determinable fair value	215,412	139,268
FHLB and FRB stock, at cost	281,407	205,003
Brokerage customer receivables	18,102	10,592
Mortgage loans held-for-sale, at fair value	331,261	292,722
Accrued interest receivable and other assets	1,739,334	1,551,899
Financial Liabilities:
Federal Home Loan Bank advances	3,151,309	2,326,071
Other borrowings	534,803	645,813
Subordinated notes	298,283	437,866
Junior subordinated debentures	253,566	253,566
Carrying Value
Financial Assets:
Cash and cash equivalents	458,536	423,464
Interest-bearing deposits with banks	4,409,753	2,084,323
Available-for-sale securities	4,141,482	3,502,915
Held-to-maturity securities	3,613,263	3,856,916
Trading account securities	4,072	4,707
Equity securities with readily determinable fair value	215,412	139,268
FHLB and FRB stock, at cost	281,407	205,003
Brokerage customer receivables	18,102	10,592
Mortgage loans held-for-sale, at fair value	331,261	292,722
Nonqualified deferred compensation assets	16,653	15,238
Derivative assets	200,027	275,726
Accrued interest receivable and other assets	563,625	477,832
Total financial assets	62,308,630	53,420,537
Financial Liabilities:
Non-maturity deposits	43,092,318	38,772,098
Deposits with stated maturities	9,420,031	6,625,072
Federal Home Loan Bank advances	3,151,309	2,326,071
Other borrowings	534,803	645,813
Subordinated notes	298,283	437,866
Junior subordinated debentures	253,566	253,566
Derivative liabilities	241,750	267,255
Accrued interest payable	48,364	51,116
Total financial liabilities	57,040,424	49,378,857
Carrying Value | Loans held-for-investment, at fair value
Financial Assets:
Loans held-for-investment	158,795	155,261
Carrying Value | Loans held-for-investment, at amortized cost
Financial Assets:
Loans held-for-investment	47,896,242	41,976,570
Fair Value
Financial Assets:
Cash and cash equivalents	458,536	423,464
Interest-bearing deposits with banks	4,409,753	2,084,323
Available-for-sale securities	4,141,482	3,502,915
Held-to-maturity securities	2,910,550	3,215,468
Trading account securities	4,072	4,707
Equity securities with readily determinable fair value	215,412	139,268
FHLB and FRB stock, at cost	281,407	205,003
Brokerage customer receivables	18,102	10,592
Mortgage loans held-for-sale, at fair value	331,261	292,722
Nonqualified deferred compensation assets	16,653	15,238
Derivative assets	200,027	275,726
Accrued interest receivable and other assets	563,625	477,832
Total financial assets	60,779,924	51,892,529
Financial Liabilities:
Non-maturity deposits	43,092,318	38,772,098
Deposits with stated maturities	9,423,976	6,603,746
Federal Home Loan Bank advances	3,153,524	2,367,107
Other borrowings	534,406	643,755
Subordinated notes	286,683	413,501
Junior subordinated debentures	253,588	253,579
Derivative liabilities	241,750	267,255
Accrued interest payable	48,364	51,116
Total financial liabilities	57,034,609	49,372,157
Fair Value | Loans held-for-investment, at fair value
Financial Assets:
Loans held-for-investment	158,795	155,261
Fair Value | Loans held-for-investment, at amortized cost
Financial Assets:
Loans held-for-investment	$ 47,070,249	$ 41,090,010