Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Dec. 31, 2022
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	$ 3,912,730	$ 3,600,892
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,799,119	3,860,235
Held-to-maturity, Fair Value	3,246,952	3,380,624
Equity Securities, FV-NI and without Readily Determinable Fair Value	22,944	41,651
FHLB and Federal Reserve Bank stocks	212,102	229,171
Assets	41,623,908	41,015,855
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	5,815,045	6,119,956
Deposits	32,691,039	33,446,049
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	359,539	326,780
Bank Term Funding Program Funding	500,000	0
Short-Term Debt	859,539	326,780
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	2,673,046	1,940,194
Liabilities	37,381,571	36,841,882
Standby letters of credit(c)
Liabilities, Fair Value Disclosure
Lending Related Commitments By Type [Domain]	252,475	212,029
Interest Rate Contract
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	44,072	32,985
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	11,409	533
Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	470,818	484,384
Interest-bearing Deposits in Banks and Other Financial Institutions	484,677	425,089
Federal funds sold and securities purchased under agreements to resell	3,600	14,350
Equity Securities, FV-NI	10,444	31,651
Equity Securities, FV-NI and without Readily Determinable Fair Value	22,944	41,651
FHLB and Federal Reserve Bank stocks	212,102	229,171
Residential Held-for-sale, Fair Value Disclosure	83,795	33,011
Loan, Held-for-Sale, Fair Value Disclosure		90,303
Loans and Leases Receivable, Net Amount	29,208,547	28,865,124
Loans Receivable, Fair Value Disclosure	27,884,450	27,371,086
Bank and corporate owned life insurance	683,451	682,649
Servicing Asset	85,640	84,390
Assets	39,080,255	38,534,897
Assets, Fair Value Disclosure	37,203,991	36,561,249
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	5,815,045	6,119,956
Deposits, Savings Deposits	5,157,103	4,835,701
Interest-Bearing Domestic Deposit, Demand	8,284,017	8,843,967
Deposits, Money Market Deposits	6,294,895	6,330,453
Brokered cds and other time deposits	4,061,578	4,447,479
Brokered cds and other time deposits fair value	4,061,578	4,447,479
Time Deposits, at Carrying Value	3,078,401	2,868,494
Time Deposits	3,078,401	2,868,494
Deposits	32,691,039	33,446,049
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	359,539	326,780
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	359,532	326,757
Bank Term Funding Program Funding	500,000
Bank Term Funding Program Funding, Fair Value Disclosure	497,973
Short-Term Debt	859,539
Short-term Debt, Fair Value	857,505
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	2,673,046	1,940,194
Federal Home Loan Bank Borrowings, Fair Value Disclosure	2,672,221	1,944,600
Other long-term funding	536,113	541,269
Long-term Debt, Fair Value	530,211	534,983
Repayments of Lines of Credit	2,536	2,157
Liabilities	36,985,572	36,459,407
Liabilities, Fair Value Disclosure	36,976,810	36,457,504
Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	95	673
Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	766	439
Fair Value, Measurements, Recurring | Designated as Hedging Instrument
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	3,036	8,075
Foreign Currency Contract, Asset, Fair Value Disclosure	136	632
Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	12,880	930
Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	337	2,946
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	106,277	111,623
Foreign Currency Contract, Asset, Fair Value Disclosure	2,700	2,954
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	207,471	195,662
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	2,514	2,746
US Treasury Securities
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	35,638	35,902
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,000	999
Held-to-maturity, Fair Value	978	963
US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	35,638	35,902
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,000	999
Held-to-maturity, Fair Value	978	963
US States and Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	78,507	91,817
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,668,494	1,682,473
Held-to-maturity, Fair Value	1,497,670	1,554,059
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	78,507	91,817
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,668,410	1,682,398
Held-to-maturity, Fair Value	1,497,587	1,553,984
Residential Related Securities | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	1,064,318	1,120,794
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	916,966	941,973
Held-to-maturity, Fair Value	753,657	804,393
Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	2,440,808	2,042,675
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	46,392	48,979
Held-to-maturity, Fair Value	42,536	46,170
Residential Related Securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	1,064,318	1,120,794
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	916,966	941,973
Held-to-maturity, Fair Value	753,657	804,393
Residential Related Securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	2,440,808	2,042,675
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	46,392	48,979
Held-to-maturity, Fair Value	42,536	46,170
Residential Related Securities | 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	335,148	345,083
Held-to-maturity, Fair Value	273,892	289,507
Commercial mortgage-related securities | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	17,283	16,937
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	776,717	780,995
Held-to-maturity, Fair Value	630,783	632,914
Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	149,799	154,793
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	54,403	59,733
Held-to-maturity, Fair Value	47,436	52,619
Commercial mortgage-related securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	17,283	16,937
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	776,717	780,995
Held-to-maturity, Fair Value	630,783	632,914
Commercial mortgage-related securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	149,799	154,793
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	54,403	59,733
Held-to-maturity, Fair Value	47,436	52,619
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	122,765	133,975
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Held-to-maturity, Fair Value	0
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	122,765	133,975
US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	640	1,051
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Held-to-maturity, Fair Value	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	640	1,051
Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	2,973	2,950
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	3,912,730	3,600,892
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	3,799,035	3,860,160
Held-to-maturity, Fair Value	3,246,868	3,380,550
Fair Value, Inputs, Level 1
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	470,818	484,384
Interest-bearing Deposits in Banks and Other Financial Institutions	484,677	425,089
Federal funds sold and securities purchased under agreements to resell	3,600	14,350
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and Due from Banks	470,818	484,384
Interest-bearing Deposits in Banks and Other Financial Institutions	484,677	425,089
Federal funds sold and securities purchased under agreements to resell	3,600	14,350
Equity Securities, FV-NI	10,382	6,883
FHLB and Federal Reserve Bank stocks	0	0
Residential Held-for-sale, Fair Value Disclosure	0	0
Loan, Held-for-Sale, Fair Value Disclosure		0
Loans Receivable, Fair Value Disclosure	0	0
Bank and corporate owned life insurance	0	0
Servicing Asset	0	0
Assets, Fair Value Disclosure	1,006,092	967,570
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 and other time deposits 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
Bank Term Funding Program Funding, Fair Value Disclosure	0
Short-term Debt, Fair Value	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0	0
Long-term Debt, Fair Value	0	0
Repayments of Lines of Credit	0	0
Liabilities, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	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 | Designated as Hedging Instrument
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 1 | US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	35,638	35,902
Held-to-maturity, Fair Value	978	963
Fair Value, Inputs, Level 1 | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Residential Related Securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Residential Related Securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Residential Related Securities | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Commercial mortgage-related securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 1 | Commercial mortgage-related securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
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]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 1 | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 1 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 1 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	35,638	35,902
Fair Value, Inputs, Level 1 | Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity, Fair Value	978	963
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Bank and corporate owned life insurance	683,451	682,649
Liabilities, Fair Value Disclosure
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	2,673,046	1,940,194
Other long-term funding	536,113	541,269
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 purchased under agreements to resell	0	0
Equity Securities, FV-NI	0	0
FHLB and Federal Reserve Bank stocks	212,102	229,171
Residential Held-for-sale, Fair Value Disclosure	83,795	33,011
Loan, Held-for-Sale, Fair Value Disclosure		90,303
Loans Receivable, Fair Value Disclosure	0	0
Bank and corporate owned life insurance	683,451	682,649
Servicing Asset	0	0
Assets, Fair Value Disclosure	8,214,480	8,102,995
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 and other time deposits fair value	4,061,578	4,447,479
Time Deposits	3,078,401	2,868,494
Deposits	7,139,979	7,315,973
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	359,532	326,757
Bank Term Funding Program Funding, Fair Value Disclosure	497,973
Short-term Debt, Fair Value	857,505
Federal Home Loan Bank Borrowings, Fair Value Disclosure	2,672,221	1,944,600
Long-term Debt, Fair Value	530,211	534,983
Repayments of Lines of Credit	2,536	2,157
Liabilities, Fair Value Disclosure	11,425,654	10,326,755
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	2,700	2,954
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	2,514	2,746
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
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 | Designated as Hedging Instrument
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	3,036	8,075
Foreign Currency Contract, Asset, Fair Value Disclosure	136	632
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	12,880	930
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	136	632
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	337	2,946
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	106,277	111,623
Foreign Currency Contract, Asset, Fair Value Disclosure	2,700	2,954
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	207,471	195,662
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	2,514	2,746
Fair Value, Inputs, Level 2 | US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
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]
AFS investment securities, at fair value	78,507	91,817
Held-to-maturity, Fair Value	1,497,587	1,553,984
Fair Value, Inputs, Level 2 | Residential Related Securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	1,064,318	1,120,794
Held-to-maturity, Fair Value	753,657	804,393
Fair Value, Inputs, Level 2 | Residential Related Securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	2,440,808	2,042,675
Held-to-maturity, Fair Value	42,536	46,170
Fair Value, Inputs, Level 2 | Residential Related Securities | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity, Fair Value	273,892	289,507
Fair Value, Inputs, Level 2 | Commercial mortgage-related securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	17,283	16,937
Held-to-maturity, Fair Value	630,783	632,914
Fair Value, Inputs, Level 2 | Commercial mortgage-related securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	149,799	154,793
Held-to-maturity, Fair Value	47,436	52,619
Fair Value, Inputs, Level 2 | Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	122,765	133,975
Fair Value, Inputs, Level 2 | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	640	1,051
Fair Value, Inputs, Level 2 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	2,973	2,950
Fair Value, Inputs, Level 2 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	3,877,092	3,564,990
Fair Value, Inputs, Level 2 | Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity, Fair Value	3,245,890	3,379,586
Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Equity Securities, FV-NI	62	24,769	$ 19,225
Loans and Leases Receivable, Net Amount	29,262,428	28,865,124
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 purchased under agreements to resell	0	0
Equity Securities, FV-NI	62	24,769
FHLB and Federal Reserve Bank stocks	0	0
Residential Held-for-sale, Fair Value Disclosure	0	0
Loan, Held-for-Sale, Fair Value Disclosure		0
Loans Receivable, Fair Value Disclosure	27,884,450	27,371,086
Bank and corporate owned life insurance	0	0
Servicing Asset	85,640	84,390
Assets, Fair Value Disclosure	27,970,919	27,480,684
Liabilities, Fair Value Disclosure
Noninterest-bearing Domestic Deposit, Demand	5,815,045	6,119,956
Deposits, Savings Deposits	5,157,103	4,835,701
Interest-Bearing Domestic Deposit, Demand	8,284,017	8,843,967
Deposits, Money Market Deposits	6,294,895	6,330,453
Brokered cds and other time deposits fair value	0	0
Time Deposits	0	0
Deposits	25,551,061	26,130,076
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0	0
Bank Term Funding Program Funding, Fair Value Disclosure	0
Short-term Debt, Fair Value	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0	0
Long-term Debt, Fair Value	0	0
Repayments of Lines of Credit	0	0
Liabilities, Fair Value Disclosure	25,551,156	26,130,749
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Commitments [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	95	673
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Interest Rate Lock Commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	766	439
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Designated as Hedging Instrument | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Asset	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Interest Rate Contract
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Liabilities, Fair Value Disclosure
Derivatives (trading liabilities)	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	766	439
Fair Value, Inputs, Level 3 | US Treasury Securities | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
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]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Residential Related Securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Residential Related Securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Residential Related Securities | Fair Value, Measurements, Recurring | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Commercial mortgage-related securities | Fair Value, Measurements, Recurring | US Government Sponsored-Enterprise Insured Loans
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, Level 3 | Commercial mortgage-related securities | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
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]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 3 | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 3 | Other Debt Obligations | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 3 | Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
AFS investment securities, at fair value	0	0
Fair Value, Inputs, Level 3 | Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity, Fair Value	0	0
Fair Value, Inputs, NAV | Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Equity Securities, FV-NI	$ 12,500	$ 10,000