v3.26.3
Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Dec. 31, 2024
Assets, Fair Value Disclosure [Abstract]      
Cash and Due from Banks $ 644,519 $ 574,698  
Interest-bearing Deposits in Banks and Other Financial Institutions 982,850 1,144,123  
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure 100 1,400  
Debt Securities, Available-for-Sale 6,198,828 5,397,563  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 3,462,220 3,602,576  
Debt Securities, Held-to-Maturity, Fair Value 2,804,882 3,190,994  
Equity Securities, FV-NI and without Readily Determinable Fair Value 30,043 26,060  
FHLB and Federal Reserve Bank stocks 304,330 252,514  
Loans and Leases Receivable, Net Amount 36,078,747 30,785,546  
Life Insurance, Corporate or Bank Owned, Amount 717,175 694,452  
Assets 51,399,852 45,202,596  
Liabilities, Fair Value Disclosure      
Noninterest-bearing Domestic Deposit, Demand 6,914,688 6,126,632  
Deposits 40,380,950 35,552,608  
Federal Funds Purchased and Securities Sold under Agreements to Repurchase 266,329 307,864  
Short-Term Debt 266,329 307,864  
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances 3,961,112 3,268,094  
Other Long-Term Debt 589,168 594,276  
Liabilities 45,924,220 40,227,249  
Standby Letters of Credit [Member]      
Liabilities, Fair Value Disclosure      
Lending Related Commitments 255,700 222,000  
Interest Rate Contract      
Assets, Fair Value Disclosure [Abstract]      
Derivative Asset 35,165 19,286  
Liabilities, Fair Value Disclosure      
Derivative Liability 19,439 1,833  
Fair Value, Measurements, Recurring      
Assets, Fair Value Disclosure [Abstract]      
Cash and Due from Banks 644,519 574,698  
Interest-bearing Deposits in Banks and Other Financial Institutions 982,850 1,144,123  
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure 100 1,400  
Equity Securities, FV-NI 15,043 11,060  
Equity Securities, FV-NI and without Readily Determinable Fair Value 30,043 26,060  
FHLB and Federal Reserve Bank stocks 304,330 252,514  
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure 66,770 72,499  
Loans and Leases Receivable, Net Amount 36,005,495 30,766,886  
Loans Receivable, Fair Value Disclosure 34,759,951 29,970,788  
Life Insurance, Corporate or Bank Owned, Amount 717,175 694,452  
Servicing Asset 94,919 86,337  
Assets 48,625,785 42,699,714  
Assets, Fair Value Disclosure 46,722,903 41,492,034  
Liabilities, Fair Value Disclosure      
Brokered CDs, Carrying Amount 3,790,075 3,795,133  
Brokered CDs, Fair Value 3,773,476 3,791,245  
Time Deposits, at Carrying Value 4,963,737 4,041,178  
Time Deposits 4,948,274 4,035,549  
Federal Funds Purchased and Securities Sold under Agreements to Repurchase 266,329 307,864  
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure 266,329 307,864  
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances 3,961,112 3,268,094  
Federal Home Loan Bank Borrowings, Fair Value Disclosure 3,950,034 3,267,836  
Other Long-Term Debt 589,168 594,276  
Long-term Debt, Fair Value 566,385 598,141  
Long-Term Line of Credit 2,365 2,225  
Liabilities 13,815,357 12,119,557  
Liabilities, Fair Value Disclosure 13,749,434 12,113,647  
Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]      
Assets, Fair Value Disclosure [Abstract]      
Derivative Asset 2,931 814  
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 308 10,517  
Liabilities, Fair Value Disclosure      
Derivative Liability 21,136 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 2,240 757  
Liabilities, Fair Value Disclosure      
Foreign Currency Contracts, Liability, Fair Value Disclosure 245 194  
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract      
Assets, Fair Value Disclosure [Abstract]      
Derivative Asset 112,606 66,787  
Liabilities, Fair Value Disclosure      
Derivative Liability 220,964 108,631  
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 451 1,731  
Liabilities, Fair Value Disclosure      
Foreign Currency Contracts, Liability, Fair Value Disclosure 226 1,517  
US Treasury Securities      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 997 996  
Debt Securities, Held-to-Maturity, Fair Value 993 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 997 996  
Debt Securities, Held-to-Maturity, Fair Value 993 1,015  
US States and Political Subdivisions Debt Securities [Member]      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 6,392 3,044  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 1,576,827 1,628,088  
Debt Securities, Held-to-Maturity, Fair Value 1,304,761 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 6,392 3,044  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 1,576,827 1,628,088  
Debt Securities, Held-to-Maturity, Fair Value 1,304,761 1,507,302  
Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 134,464 129,863  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 771,047 823,630  
Debt Securities, Held-to-Maturity, Fair Value 598,700 696,462  
Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member]      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 5,352,106 5,039,829  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 36,181 39,123  
Debt Securities, Held-to-Maturity, Fair Value 31,634 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 134,464 129,863  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 771,047 823,630  
Debt Securities, Held-to-Maturity, Fair Value 598,700 696,462  
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 5,352,106 5,039,829  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 36,181 39,123  
Debt Securities, Held-to-Maturity, Fair Value 31,634 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 284,928 302,817  
Debt Securities, Held-to-Maturity, Fair Value 224,916 258,827  
Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 347,399 16,958  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 752,924 763,370  
Debt Securities, Held-to-Maturity, Fair Value 609,904 650,366  
Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member]      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 102,863 109,556  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 39,316 44,552  
Debt Securities, Held-to-Maturity, Fair Value 33,974 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 347,399 16,958  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 752,924 763,370  
Debt Securities, Held-to-Maturity, Fair Value 609,904 650,366  
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 102,863 109,556  
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss 39,316 44,552  
Debt Securities, Held-to-Maturity, Fair Value 33,974 40,138  
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 86,048 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 86,048 95,046  
US Government-sponsored Enterprises Debt Securities [Member]      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 164,502 269  
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 164,502 269  
Other Debt Obligations | Fair Value, Measurements, Recurring      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 5,054 2,998  
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 6,198,828 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 3,462,220 3,602,576  
Debt Securities, Held-to-Maturity, Fair Value 2,804,882 3,190,994  
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring      
Assets, Fair Value Disclosure [Abstract]      
Cash and Due from Banks 644,519 574,698  
Interest-bearing Deposits in Banks and Other Financial Institutions 982,850 1,144,123  
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure 100 1,400  
Equity Securities, FV-NI 15,043 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 1,643,505 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 266,329 307,864  
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 266,329 307,864  
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 993 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 993 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 304,330 252,514  
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure 66,770 72,499  
Loans Receivable, Fair Value Disclosure 0 0  
Life Insurance, Corporate or Bank Owned, Amount 717,175 694,452  
Servicing Asset 0 0  
Assets, Fair Value Disclosure 10,204,534 9,686,799  
Liabilities, Fair Value Disclosure      
Brokered CDs, Fair Value 3,773,476 3,791,245  
Time Deposits 4,948,274 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 3,950,034 3,267,836  
Long-term Debt, Fair Value 566,385 598,141  
Long-Term Line of Credit 2,365 2,225  
Liabilities, Fair Value Disclosure 13,483,105 11,805,339  
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Foreign Exchange Forward [Member]      
Assets, Fair Value Disclosure [Abstract]      
Derivative Asset 451 1,731  
Liabilities, Fair Value Disclosure      
Derivative Liability 226 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 308 10,517  
Liabilities, Fair Value Disclosure      
Derivative Liability 21,136 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 2,240 757  
Foreign Currency Contract, Asset, Fair Value Disclosure 2,240 757  
Liabilities, Fair Value Disclosure      
Derivative Liability 245 194  
Foreign Currency Contracts, Liability, Fair Value Disclosure 245 194  
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 112,606 66,787  
Liabilities, Fair Value Disclosure      
Derivative Liability 220,964 108,631  
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 451 1,731  
Liabilities, Fair Value Disclosure      
Foreign Currency Contracts, Liability, Fair Value Disclosure 226 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 6,392 3,044  
Debt Securities, Held-to-Maturity, Fair Value 1,304,761 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 134,464 129,863  
Debt Securities, Held-to-Maturity, Fair Value 598,700 696,462  
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 5,352,106 5,039,829  
Debt Securities, Held-to-Maturity, Fair Value 31,634 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 224,916 258,827  
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 347,399 16,958  
Debt Securities, Held-to-Maturity, Fair Value 609,904 650,366  
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 102,863 109,556  
Debt Securities, Held-to-Maturity, Fair Value 33,974 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 86,048 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 164,502 269  
Fair Value, Inputs, Level 2 | Other Debt Obligations | Fair Value, Measurements, Recurring      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 2,991 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 6,196,765 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 2,803,889 3,189,979  
Fair Value, Inputs, Level 3      
Assets, Fair Value Disclosure [Abstract]      
Debt Securities, Available-for-Sale 2,100    
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 34,759,951 29,970,788  
Life Insurance, Corporate or Bank Owned, Amount 0 0  
Servicing Asset 94,919 86,337  
Assets, Fair Value Disclosure 34,859,864 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 2,931 814  
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 2,931 814  
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 2,063 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 2,063 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