Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	$ 1,458,665	$ 1,494,514
Deposits	14,913,900	14,437,648
Federal funds purchased and securities sold under repurchase agreements	311,179	449,331
Other borrowings	1,056,714	1,050,938
Subordinated notes	123,372	123,262
Junior subordinated debt securities	61,856	61,856
Level 2 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	832,052	738,787
Securities held to maturity	1,458,665	1,494,514
Deposits	14,913,900	14,437,648
Federal funds purchased and securities sold under repurchase agreements	311,179	449,331
Other borrowings	1,056,714	1,050,938
Subordinated notes	123,372	123,262
Junior subordinated debt securities	61,856	61,856
Level 2 [Member] | Estimate Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	832,052	738,787
Securities held to maturity	1,366,377	1,406,589
Deposits	14,881,501	14,404,661
Federal funds purchased and securities sold under repurchase agreements	311,179	449,331
Other borrowings	1,056,709	1,050,932
Subordinated notes	103,438	113,125
Junior subordinated debt securities	46,083	46,392
Level 3 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net LHFI	12,484,669	12,083,825
Level 3 [Member] | Estimate Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net LHFI	$ 12,335,167	$ 11,850,318