Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	$ 465,318	$ 574,698
Interest-bearing Deposits in Banks and Other Financial Institutions	920,684	1,144,123
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	175	1,400
Debt Securities, Available-for-Sale	5,514,456	5,397,563
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,570,901	3,602,576
Debt Securities, Held-to-Maturity, Fair Value	3,122,449	3,190,994
Equity Securities, FV-NI and without Readily Determinable Fair Value	26,109	26,060
FHLB and Federal Reserve Bank stocks	290,189	252,514
Loans and Leases Receivable, Net Amount	31,412,408	30,785,546
Life Insurance, Corporate or Bank Owned, Amount	694,765	694,452
Assets	45,593,740	45,202,596
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	6,125,067	6,126,632
Deposits	35,731,765	35,552,608
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	395,652	307,864
Short-Term Debt	395,652	307,864
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,421,762	3,268,094
Other Long-Term Debt	592,629	594,276
Liabilities	40,595,868	40,227,249
Standby Letters of Credit [Member]
Liabilities, Fair Value Disclosure
Lending Related Commitments	241,200	222,000
Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	15,234	19,286
Liabilities, Fair Value Disclosure
Derivative Liability	(1,926)	1,833
Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	465,318	574,698
Interest-bearing Deposits in Banks and Other Financial Institutions	920,684	1,144,123
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	175	1,400
Equity Securities, FV-NI	11,109	11,060
Equity Securities, FV-NI and without Readily Determinable Fair Value	26,109	26,060
FHLB and Federal Reserve Bank stocks	290,189	252,514
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	87,461	72,499
Loans and Leases Receivable, Net Amount	31,373,006	30,766,886
Loans Receivable, Fair Value Disclosure	30,475,513	29,970,788
Life Insurance, Corporate or Bank Owned, Amount	694,765	694,452
Servicing Asset	87,599	86,337
Assets	43,096,031	42,699,714
Assets, Fair Value Disclosure	41,750,086	41,492,034
Liabilities, Fair Value Disclosure
Brokered CDs, Carrying Amount	3,562,752	3,795,133
Brokered CDs, Fair Value	3,556,597	3,791,245
Time Deposits, at Carrying Value	4,484,077	4,041,178
Time Deposits	4,478,871	4,035,549
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	395,652	307,864
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	395,652	307,864
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,421,762	3,268,094
Federal Home Loan Bank Borrowings, Fair Value Disclosure	3,414,381	3,267,836
Other Long-Term Debt	592,629	594,276
Long-term Debt, Fair Value	593,506	598,141
Long-Term Line of Credit	2,433	2,225
Liabilities	12,563,438	12,119,557
Liabilities, Fair Value Disclosure	12,545,573	12,113,647
Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	1,777	814
Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivative Liability		444
Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	4,253	10,517
Liabilities, Fair Value Disclosure
Derivative Liability	2,326	1
Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	827	757
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	402	194
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	58,177	66,787
Liabilities, Fair Value Disclosure
Derivative Liability	101,284	108,631
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	334	1,731
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	121	1,517
US Treasury Securities
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	996	996
Debt Securities, Held-to-Maturity, Fair Value	1,007	1,015
US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	996	996
Debt Securities, Held-to-Maturity, Fair Value	1,007	1,015
US States and Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	3,020	3,044
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,618,922	1,628,088
Debt Securities, Held-to-Maturity, Fair Value	1,462,907	1,507,302
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	3,020	3,044
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,618,922	1,628,088
Debt Securities, Held-to-Maturity, Fair Value	1,462,907	1,507,302
Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	131,583	129,863
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	811,047	823,630
Debt Securities, Held-to-Maturity, Fair Value	681,846	696,462
Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,096,659	5,039,829
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	38,021	39,123
Debt Securities, Held-to-Maturity, Fair Value	35,689	36,884
Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	131,583	129,863
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	811,047	823,630
Debt Securities, Held-to-Maturity, Fair Value	681,846	696,462
Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,096,659	5,039,829
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	38,021	39,123
Debt Securities, Held-to-Maturity, Fair Value	35,689	36,884
Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	298,196	302,817
Debt Securities, Held-to-Maturity, Fair Value	253,234	258,827
Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	16,936	16,958
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	761,410	763,370
Debt Securities, Held-to-Maturity, Fair Value	649,810	650,366
Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	108,131	109,556
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,309	44,552
Debt Securities, Held-to-Maturity, Fair Value	37,956	40,138
Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	16,936	16,958
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	761,410	763,370
Debt Securities, Held-to-Maturity, Fair Value	649,810	650,366
Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	108,131	109,556
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,309	44,552
Debt Securities, Held-to-Maturity, Fair Value	37,956	40,138
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	91,828	95,046
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Debt Securities, Held-to-Maturity, Fair Value	0
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	91,828	95,046
US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	63,301	269
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Debt Securities, Held-to-Maturity, Fair Value	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	63,301	269
Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	2,998	2,998
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,514,456	5,397,563
Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,570,901	3,602,576
Debt Securities, Held-to-Maturity, Fair Value	3,122,449	3,190,994
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	465,318	574,698
Interest-bearing Deposits in Banks and Other Financial Institutions	920,684	1,144,123
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	175	1,400
Equity Securities, FV-NI	11,109	11,060
FHLB and Federal Reserve Bank stocks	0	0
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	0	0
Loans Receivable, Fair Value Disclosure	0	0
Life Insurance, Corporate or Bank Owned, Amount	0	0
Servicing Asset	0	0
Assets, Fair Value Disclosure	1,398,293	1,732,296
Liabilities, Fair Value Disclosure
Brokered CDs, Fair Value	0	0
Time Deposits	0	0
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	395,652	307,864
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0	0
Long-term Debt, Fair Value	0	0
Long-Term Line of Credit	0	0
Liabilities, Fair Value Disclosure	395,652	307,864
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivative Liability		0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Liabilities, Fair Value Disclosure
Derivative Liability	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Liabilities, Fair Value Disclosure
Derivative Liability	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	1,007	1,015
Fair Value, Inputs, Level 1 | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 1 | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 1 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 1 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 1 | Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	1,007	1,015
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	0	0
Interest-bearing Deposits in Banks and Other Financial Institutions	0	0
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	0
Equity Securities, FV-NI	0	0
FHLB and Federal Reserve Bank stocks	290,189	252,514
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	87,461	72,499
Loans Receivable, Fair Value Disclosure	0	0
Life Insurance, Corporate or Bank Owned, Amount	694,765	694,452
Servicing Asset	0	0
Assets, Fair Value Disclosure	9,771,904	9,686,799
Liabilities, Fair Value Disclosure
Brokered CDs, Fair Value	3,556,597	3,791,245
Time Deposits	4,478,871	4,035,549
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	3,414,381	3,267,836
Long-term Debt, Fair Value	593,506	598,141
Long-Term Line of Credit	2,433	2,225
Liabilities, Fair Value Disclosure	12,149,921	11,805,339
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	334	1,731
Liabilities, Fair Value Disclosure
Derivative Liability	121	1,517
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivative Liability		0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	4,253	10,517
Liabilities, Fair Value Disclosure
Derivative Liability	2,326	1
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	827	757
Foreign Currency Contract, Asset, Fair Value Disclosure	827	757
Liabilities, Fair Value Disclosure
Derivative Liability	402	194
Foreign Currency Contracts, Liability, Fair Value Disclosure	402	194
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	58,177	66,787
Liabilities, Fair Value Disclosure
Derivative Liability	101,284	108,631
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	334	1,731
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	121	1,517
Fair Value, Inputs, Level 2 | US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 2 | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	3,020	3,044
Debt Securities, Held-to-Maturity, Fair Value	1,462,907	1,507,302
Fair Value, Inputs, Level 2 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	131,583	129,863
Debt Securities, Held-to-Maturity, Fair Value	681,846	696,462
Fair Value, Inputs, Level 2 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,096,659	5,039,829
Debt Securities, Held-to-Maturity, Fair Value	35,689	36,884
Fair Value, Inputs, Level 2 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	253,234	258,827
Fair Value, Inputs, Level 2 | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	16,936	16,958
Debt Securities, Held-to-Maturity, Fair Value	649,810	650,366
Fair Value, Inputs, Level 2 | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	108,131	109,556
Debt Securities, Held-to-Maturity, Fair Value	37,956	40,138
Fair Value, Inputs, Level 2 | Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	91,828	95,046
Fair Value, Inputs, Level 2 | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	63,301	269
Fair Value, Inputs, Level 2 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	2,998	2,998
Fair Value, Inputs, Level 2 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,514,456	5,397,563
Fair Value, Inputs, Level 2 | Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	3,121,442	3,189,979
Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Equity Securities, FV-NI		0	$ 72
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	0	0
Interest-bearing Deposits in Banks and Other Financial Institutions	0	0
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	0
Equity Securities, FV-NI	0	0
FHLB and Federal Reserve Bank stocks	0	0
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	0	0
Loans Receivable, Fair Value Disclosure	30,475,513	29,970,788
Life Insurance, Corporate or Bank Owned, Amount	0	0
Servicing Asset	87,599	86,337
Assets, Fair Value Disclosure	30,564,889	30,057,939
Liabilities, Fair Value Disclosure
Brokered CDs, Fair Value	0	0
Time Deposits	0	0
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0	0
Long-term Debt, Fair Value	0	0
Long-Term Line of Credit	0	0
Liabilities, Fair Value Disclosure	0	444
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	1,777	814
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivative Liability		444
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Liabilities, Fair Value Disclosure
Derivative Liability	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Liabilities, Fair Value Disclosure
Derivative Liability	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	1,777	814
Fair Value, Inputs, Level 3 | US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 3 | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 3 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 3 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	0	0
Fair Value, Inputs, Level 3 | Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Fair Value	0	0
Fair Value, Inputs, NAV [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Equity Securities, FV-NI	$ 15,000	$ 15,000