Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024	Dec. 31, 2023
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	$ 521,167	$ 544,059
Interest-bearing Deposits in Banks and Other Financial Institutions	738,938	453,590
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	21,955
Debt Securities, Available-for-Sale	5,036,508	4,581,434
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,672,161	3,738,747
Debt Securities, Held-to-Maturity, Fair Value	3,140,331	3,185,494
Equity Securities, FV-NI and without Readily Determinable Fair Value	25,912	23,242
FHLB and Federal Reserve Bank stocks	278,356	179,665
Loans and Leases Receivable, Net Amount	30,231,091	29,405,041
Life Insurance, Corporate or Bank Owned, Amount	691,470	689,000
Assets	43,993,729	43,023,068
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	5,782,487	5,775,657
Deposits	34,147,565	34,648,434
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	75,585	470,369
Short-Term Debt	75,585	470,369
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,879,489	1,853,807
Other Long-Term Debt	593,530	837,635
Liabilities	39,212,948	38,417,506
Standby Letters of Credit [Member]
Liabilities, Fair Value Disclosure
Lending Related Commitments	238,000	253,700
Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	23,398	31,950
Liabilities, Fair Value Disclosure
Derivative Liability	3,705	1,452
Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	521,167	544,059
Interest-bearing Deposits in Banks and Other Financial Institutions	738,938	453,590
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	21,955
Equity Securities, FV-NI	10,912	10,742
Equity Securities, FV-NI and without Readily Determinable Fair Value	25,912	23,242
FHLB and Federal Reserve Bank stocks	278,356	179,665
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	96,804	646,687
Loan, Held-for-Sale, Fair Value Disclosure	8,406	32,634
Loans and Leases Receivable, Net Amount	30,252,521	29,373,557
Loans Receivable, Fair Value Disclosure	29,483,667	28,327,115
Life Insurance, Corporate or Bank Owned, Amount	691,470	689,000
Servicing Asset	85,245	87,683
Assets	41,500,762	40,471,048
Assets, Fair Value Disclosure	40,200,079	38,871,352
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	5,782,487	5,775,657
Deposits, Savings Deposits	5,291,674	5,133,295
Interest-Bearing Domestic Deposit, Demand	8,579,678	9,124,741
Deposits, Money Market Deposits	6,619,323	6,637,915
Brokered CDs, Carrying Amount	4,072,048	4,276,309
Brokered CDs, Fair Value	4,072,048	4,276,309
Time Deposits, at Carrying Value	3,802,356	3,700,518
Time Deposits	3,802,356	3,700,518
Deposits	34,147,565	34,648,434
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	75,585	470,369
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	75,586	470,370
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,879,489	1,853,807
Federal Home Loan Bank Borrowings, Fair Value Disclosure	3,881,930	1,852,685
Other Long-Term Debt	593,530	837,635
Long-term Debt, Fair Value	596,673	823,991
Long-Term Line of Credit	2,386	2,546
Liabilities	38,829,803	37,991,364
Liabilities, Fair Value Disclosure	38,835,388	37,976,599
Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	1,921	327
Fair Value, Measurements, Recurring | Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset		254
Liabilities, Fair Value Disclosure
Derivative Liability	1,362
Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	10,652	2,960
Liabilities, Fair Value Disclosure
Derivative Liability	170	2,976
Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	423	2,457
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	3,108	563
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	77,258	88,541
Liabilities, Fair Value Disclosure
Derivative Liability	123,694	170,928
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	3,078	4,315
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	2,912	4,106
US Treasury Securities
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	994	1,000
Debt Securities, Held-to-Maturity, Fair Value	1,013	999
US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	994	1,000
Debt Securities, Held-to-Maturity, Fair Value	1,013	999
US States and Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	2,993	3,005
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,643,021	1,659,722
Debt Securities, Held-to-Maturity, Fair Value	1,441,969	1,486,642
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	2,993	3,005
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,642,962	1,659,662
Debt Securities, Held-to-Maturity, Fair Value	1,441,910	1,486,582
Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	119,914	110,928
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	854,777	885,476
Debt Securities, Held-to-Maturity, Fair Value	707,296	721,946
Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	4,682,415	4,227,727
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,028	43,693
Debt Securities, Held-to-Maturity, Fair Value	39,136	39,927
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	119,914	110,928
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	854,777	885,476
Debt Securities, Held-to-Maturity, Fair Value	707,296	721,946
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	4,682,415	4,227,727
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,028	43,693
Debt Securities, Held-to-Maturity, Fair Value	39,136	39,927
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	313,439	324,182
Debt Securities, Held-to-Maturity, Fair Value	262,536	266,353
Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	16,937	17,000
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	768,503	772,456
Debt Securities, Held-to-Maturity, Fair Value	644,422	623,595
Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	110,386	111,475
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	49,399	52,219
Debt Securities, Held-to-Maturity, Fair Value	43,959	46,032
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	16,937	17,000
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	768,503	772,456
Debt Securities, Held-to-Maturity, Fair Value	644,422	623,595
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	110,386	111,475
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	49,399	52,219
Debt Securities, Held-to-Maturity, Fair Value	43,959	46,032
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	100,489	107,839
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	100,489	107,839
US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	377	471
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	377	471
Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	2,998	2,989
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,036,508	4,581,434
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	3,672,101	3,738,687
Debt Securities, Held-to-Maturity, Fair Value	3,140,272	3,185,434
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	521,167	544,059
Interest-bearing Deposits in Banks and Other Financial Institutions	738,938	453,590
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0	21,955
Equity Securities, FV-NI	10,853	10,670
FHLB and Federal Reserve Bank stocks	0	0
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	0	0
Loan, 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	1,271,971	1,031,273
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	0	0
Deposits, Savings Deposits	0	0
Interest-Bearing Domestic Deposit, Demand	0	0
Deposits, Money Market Deposits	0	0
Brokered CDs, Fair Value	0	0
Time Deposits	0	0
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	0
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]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset		0
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	1,013	999
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	1,013	999
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	278,356	179,665
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	96,804	646,687
Loan, Held-for-Sale, Fair Value Disclosure	8,406	32,634
Loans Receivable, Fair Value Disclosure	0	0
Life Insurance, Corporate or Bank Owned, Amount	691,470	689,000
Servicing Asset	0	0
Assets, Fair Value Disclosure	9,342,216	9,412,129
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	0	0
Deposits, Savings Deposits	0	0
Interest-Bearing Domestic Deposit, Demand	0	0
Deposits, Money Market Deposits	0	0
Brokered CDs, Fair Value	4,072,048	4,276,309
Time Deposits	3,802,356	3,700,518
Deposits	7,874,404	7,976,827
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	75,586	470,370
Federal Home Loan Bank Borrowings, Fair Value Disclosure	3,881,930	1,852,685
Long-term Debt, Fair Value	596,673	823,991
Long-Term Line of Credit	2,386	2,546
Liabilities, Fair Value Disclosure	12,560,864	11,304,992
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	3,078	4,315
Liabilities, Fair Value Disclosure
Derivative Liability	2,912	4,106
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]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset		0
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	10,652	2,960
Liabilities, Fair Value Disclosure
Derivative Liability	170	2,976
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	423	2,457
Foreign Currency Contract, Asset, Fair Value Disclosure	423	2,457
Liabilities, Fair Value Disclosure
Derivative Liability	3,108	563
Foreign Currency Contracts, Liability, Fair Value Disclosure	3,108	563
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	77,258	88,541
Liabilities, Fair Value Disclosure
Derivative Liability	123,694	170,928
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	3,078	4,315
Liabilities, Fair Value Disclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure	2,912	4,106
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	2,993	3,005
Debt Securities, Held-to-Maturity, Fair Value	1,441,910	1,486,582
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	119,914	110,928
Debt Securities, Held-to-Maturity, Fair Value	707,296	721,946
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	4,682,415	4,227,727
Debt Securities, Held-to-Maturity, Fair Value	39,136	39,927
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	262,536	266,353
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	16,937	17,000
Debt Securities, Held-to-Maturity, Fair Value	644,422	623,595
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	110,386	111,475
Debt Securities, Held-to-Maturity, Fair Value	43,959	46,032
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	100,489	107,839
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	377	471
Fair Value, Inputs, Level 2 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	2,998	2,989
Fair Value, Inputs, Level 2 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-Sale	5,036,508	4,581,434
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	3,139,259	3,184,435
Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Equity Securities, FV-NI	59	72	$ 24,769
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	59	72
FHLB and Federal Reserve Bank stocks	0	0
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure	0	0
Loan, Held-for-Sale, Fair Value Disclosure	0	0
Loans Receivable, Fair Value Disclosure	29,483,667	28,327,115
Life Insurance, Corporate or Bank Owned, Amount	0	0
Servicing Asset	85,245	87,683
Assets, Fair Value Disclosure	29,570,892	28,415,450
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	5,782,487	5,775,657
Deposits, Savings Deposits	5,291,674	5,133,295
Interest-Bearing Domestic Deposit, Demand	8,579,678	9,124,741
Deposits, Money Market Deposits	6,619,323	6,637,915
Brokered CDs, Fair Value	0	0
Time Deposits	0	0
Deposits	26,273,162	26,671,607
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	26,274,524	26,671,607
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	1,921	327
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset		254
Liabilities, Fair Value Disclosure
Derivative Liability	1,362
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	1,921	580
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	$ 12,500