Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets [Abstract]
Debt Securities, Available-for-Sale	$ 4,152,527	$ 3,600,892
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss	3,769,150	3,860,160
Equity Securities, FV-NI and without Readily Determinable Fair Value	23,158	41,651
Loans and Leases Receivable, Net of Deferred Income	29,990,897	29,216,218
Loans and Leases Receivable, Allowance	(361,765)	(351,094)
Other Short-Term Investments	265,385	258,067
Property, Plant and Equipment, Net	373,816	372,978
Goodwill	1,104,992	1,104,992
Intangible Assets, Net (Excluding Goodwill)	33,863	40,471
Servicing Asset at Fair Value, Amount	81,977	84,390
Interest Receivable	167,777	169,569
Other Assets	698,073	658,604
Assets, Total	42,210,815	41,015,855
Liabilities and Equity [Abstract]
Interest-Bearing Deposit Liabilities, Domestic	27,696,877	27,326,093
Deposits, Total	33,554,298	33,446,049
Short-Term Debt	917,028	326,780
Federal Home Loan Bank, Advance, Branch of FHLBank, Amount	1,913,294	1,940,194
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	35,776	34,776
Other Liabilities	532,842	552,814
Liabilities, Total	37,797,579	36,841,882
Equity, Attributable to Parent [Abstract]
Preferred Stock, Including Additional Paid in Capital	194,112	194,112
Common Stock, Value, Issued	1,752	1,752
Additional Paid in Capital, Common Stock	1,714,055	1,714,822
Retained Earnings (Accumulated Deficit)	3,122,307	2,946,805
Accumulated Other Comprehensive Income (Loss), Net of Tax	(111,748)	(171,096)
Treasury Stock, Value	(507,241)	(512,421)
Total Common Equity	4,219,125	3,979,861
Equity, Attributable to Parent, Total	4,413,236	4,173,973
Liabilities and Equity, Total	$ 42,210,815	$ 41,015,855
Preferred Stock, Shares Authorized	750,000	750,000
Preferred Stock, Shares Issued	200,000	200,000
Common Stock, Shares Authorized	250,000,000	250,000,000
Common Stock, Shares, Issued	175,216,409	175,216,409
Common Stock, Shares, Outstanding	151,212,711	151,036,674
Preferred Stock, Par or Stated Value Per Share	$ 1.00	$ 1.00
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Residential Mortgage [Member]
Assets [Abstract]
Loans and Leases Receivable, Net of Deferred Income	$ 7,803,083	$ 7,864,891
Liabilities and Equity [Abstract]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	775	835
Fair Value, Inputs, Level 1
Assets [Abstract]
Cash and Due from Banks	554,631	484,384
Interest-Bearing Deposits in Banks and Other Financial Institutions	408,101	425,089
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	4,310	14,350
Fair Value, Inputs, Level 2
Assets [Abstract]
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	178,168	229,171
Life Insurance, Corporate or Bank Owned, Amount	686,704	682,649
Liabilities and Equity [Abstract]
Federal Home Loan Bank, Advance, Branch of FHLBank, Amount	1,913,294	1,940,194
Other Long-Term Debt	844,342	541,269
Fair Value, Inputs, Level 2 | Residential Mortgage [Member]
Assets [Abstract]
Financing Receivable, Held-for-Sale	67,219	33,011
Fair Value, Inputs, Level 2 | Commercial Loan
Assets [Abstract]
Financing Receivable, Held-for-Sale	11,833	90,303
Fair Value, Inputs, Level 3
Assets [Abstract]
Loans and Leases Receivable, Net Amount	29,629,131	28,865,124
Servicing Asset at Fair Value, Amount	81,977	84,390
Liabilities and Equity [Abstract]
Noninterest-Bearing Domestic Deposit, Demand	$ 5,857,421	$ 6,119,956