Fair Value - Financial Instruments not Required to be Carried at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Financial assets:
Investment securities held-to-maturity	$ 3,401,006	$ 3,574,856
Lease and lease commitments excluded
Financing leases	425,200	379,800
Deposit liabilities with no defined or contractual maturity	17,000,000	17,900,000
Book Value
Financial assets:
Cash and cash equivalents	1,114,759	1,739,897
Investment securities held-to-maturity	3,917,175	4,041,449
Loans held for sale	2,820	190
Loans	13,934,709	13,973,688
Financial liabilities:
Time deposits	3,294,705	3,456,158
Short-term borrowings	500,000	500,000
Estimate of Fair Value Measurement [Member]
Financial assets:
Cash and cash equivalents	1,114,759	1,739,897
Investment securities held-to-maturity	3,401,006	3,574,856
Loans held for sale	2,836	192
Loans	13,192,228	13,385,683
Financial liabilities:
Time deposits	3,270,205	3,432,330
Short-term borrowings	499,105	495,306
Estimate of Fair Value Measurement [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and cash equivalents	290,501	185,015
Estimate of Fair Value Measurement [Member] | Significant Other Observable Inputs (Level 2)
Financial assets:
Cash and cash equivalents	824,258	1,554,882
Investment securities held-to-maturity	3,401,006	3,574,856
Loans held for sale	2,836	192
Financial liabilities:
Time deposits	3,270,205	3,432,330
Short-term borrowings	499,105	495,306
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3)
Financial assets:
Loans	$ 13,192,228	$ 13,385,683