Fair Value - Financial Instruments not Required to be Carried at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financial assets:
Investment securities held-to-maturity	$ 3,574,856	$ 3,814,822
Lease and lease commitments excluded
Financing leases	379,800	298,100
Deposit liabilities with no defined or contractual maturity	17,900,000	19,200,000
Book Value
Financial assets:
Cash and cash equivalents	1,739,897	526,624
Investment securities held-to-maturity	4,041,449	4,320,639
Loans held for sale	190
Loans	13,973,688	13,793,922
Financial liabilities:
Time deposits	3,456,158	2,476,050
Short-term borrowings	500,000	75,000
Estimated Fair Value
Financial assets:
Cash and cash equivalents	1,739,897	526,624
Investment securities held-to-maturity	3,574,856	3,814,822
Loans held for sale	192
Loans	13,385,683	13,138,787
Financial liabilities:
Time deposits	3,432,330	2,423,231
Short-term borrowings	495,306	74,991
Estimated Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and cash equivalents	185,015	297,502
Estimated Fair Value | Significant Other Observable Inputs (Level 2)
Financial assets:
Cash and cash equivalents	1,554,882	229,122
Investment securities held-to-maturity	3,574,856	3,814,822
Loans held for sale	192
Financial liabilities:
Time deposits	3,432,330	2,423,231
Short-term borrowings	495,306	74,991
Estimated Fair Value | Significant Unobservable Inputs (Level 3)
Financial assets:
Loans	$ 13,385,683	$ 13,138,787