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Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 9,558,893	$ 9,215,376
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(86,502)
Derivative Financial Instruments, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(86,502)	(85,899)
U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	168,717	202,952
U.S. Government agency and sponsored enterprise residential MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,695,502	2,649,690
U.S. Government agency and sponsored enterprise commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	526,725	495,753
Private label residential MBS and CMOs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,356,205	2,238,046
Private label commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,260,380	1,784,029
Single family real estate-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	227,081	327,081
Collateralized loan obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	988,355	1,132,699
Non-mortgage asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	67,898	94,454
State and municipal obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	105,765	104,010
SBA securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	61,785	72,702
Marketable equity securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	8,669	28,828
Derivative Financial Instruments, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	91,811	85,132
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	177,386	231,780
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0
Fair Value, Inputs, Level 1 | Derivative Financial Instruments, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	168,717	202,952
Fair Value, Inputs, Level 1 | U.S. Government agency and sponsored enterprise residential MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | U.S. Government agency and sponsored enterprise commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Private label residential MBS and CMOs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Private label commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Single family real estate-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Collateralized loan obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Non-mortgage asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | State and municipal obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | SBA securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Marketable equity securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	8,669	28,828
Fair Value, Inputs, Level 1 | Derivative Financial Instruments, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	9,381,507	8,983,596
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(86,502)
Fair Value, Inputs, Level 2 | Derivative Financial Instruments, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(86,502)	(85,899)
Fair Value, Inputs, Level 2 | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 | U.S. Government agency and sponsored enterprise residential MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,695,502	2,649,690
Fair Value, Inputs, Level 2 | U.S. Government agency and sponsored enterprise commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	526,725	495,753
Fair Value, Inputs, Level 2 | Private label residential MBS and CMOs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,356,205	2,238,046
Fair Value, Inputs, Level 2 | Private label commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,260,380	1,784,029
Fair Value, Inputs, Level 2 | Single family real estate-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	227,081	327,081
Fair Value, Inputs, Level 2 | Collateralized loan obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	988,355	1,132,699
Fair Value, Inputs, Level 2 | Non-mortgage asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	67,898	94,454
Fair Value, Inputs, Level 2 | State and municipal obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	105,765	104,010
Fair Value, Inputs, Level 2 | SBA securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	61,785	72,702
Fair Value, Inputs, Level 2 | Marketable equity securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 | Derivative Financial Instruments, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 91,811	$ 85,132

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