Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	$ 1,474,338	$ 1,494,514
Deposits	14,783,661	14,437,648
Federal funds purchased and securities sold under repurchase agreements	477,980	449,331
Other borrowings	1,485,181	1,050,938
Subordinated notes	123,317	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	1,297,144	738,787
Securities held to maturity	1,474,338	1,494,514
Deposits	14,783,661	14,437,648
Federal funds purchased and securities sold under repurchase agreements	477,980	449,331
Other borrowings	1,485,181	1,050,938
Subordinated notes	123,317	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	1,297,144	738,787
Securities held to maturity	1,406,405	1,406,589
Deposits	14,752,438	14,404,661
Federal funds purchased and securities sold under repurchase agreements	477,980	449,331
Other borrowings	1,485,175	1,050,932
Subordinated notes	106,875	113,125
Junior subordinated debt securities	45,773	46,392
Level 3 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net LHFI	12,374,956	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	$ 12,211,328	$ 11,850,318