Fair Value Measurements (Details 2) - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
ASSETS
Held to Maturity, Fair Value, Total		$ 1,357,869	$ 1,417,608
Federal Home Loan Bank Stock		32,738	43,557
Bank Owned Life Insurance		300,111	297,387
LIABILITIES
Federal Home Loan Bank borrowings (f)		630,527	1,105,541
Subordinated Debt		0	49,980
Deposits [Member]
LIABILITIES
Time certificates of deposits (f)	[1]	12,718,154	12,684,068
Accrued Liabilities, Fair Value Disclosure	[1]	12,718,154	12,684,068
Time certificates of deposits (f)
LIABILITIES
Time certificates of deposits (f)	[2]	2,691,433	2,181,479
Accrued Liabilities, Fair Value Disclosure	[2]	2,677,849	2,166,573
Federal Home Loan Bank borrowings (f)
LIABILITIES
Federal Home Loan Bank borrowings (f)	[2]	630,527	1,105,541
Federal Home Loan Bank Borrowings, Fair Value Disclosure	[2]	629,767	1,103,845
Junior subordinated debentures (g)
LIABILITIES
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	[3]	62,859	62,858
Accrued Liabilities, Fair Value Disclosure	[3]	59,657	58,911
Subordinated debentures (f)
LIABILITIES
Subordinated Debt	[2]		49,980
Accrued Liabilities, Fair Value Disclosure	[2]		49,613
Significant Other Observable Inputs (Level 2) | Deposits [Member]
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[1]	12,718,154	12,684,068
Significant Other Observable Inputs (Level 2) | Time certificates of deposits (f)
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[2]	2,677,849	2,166,573
Significant Other Observable Inputs (Level 2) | Federal Home Loan Bank borrowings (f)
LIABILITIES
Federal Home Loan Bank Borrowings, Fair Value Disclosure	[2]	629,767	1,103,845
Significant Other Observable Inputs (Level 2) | Junior subordinated debentures (g)
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[3]	59,657	58,911
Significant Unobservable Inputs (Level 3) | Subordinated debentures (f)
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[2]		49,613
U.S. Government agency securities
ASSETS
Debt Securities, Held-to-maturity		28,655	29,521	[4]
Held to Maturity, Fair Value, Total		28,106	28,408	[4]
U.S. Government agency securities | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total		28,106	28,408	[4]
U.S. treasury securities
ASSETS
Debt Securities, Held-to-maturity	[4]	100,751	100,712
Held to Maturity, Fair Value, Total	[4]	91,082	91,535
U.S. treasury securities | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	91,082	91,535
Agency mortgage-backed securities
ASSETS
Debt Securities, Held-to-maturity	[4]	809,636	829,431
Held to Maturity, Fair Value, Total	[4]	738,491	763,728
Agency mortgage-backed securities | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	738,491	763,728
Agency collateralized mortgage obligations
ASSETS
Debt Securities, Held-to-maturity	[4]	451,912	477,517
Held to Maturity, Fair Value, Total	[4]	379,946	407,911
Agency collateralized mortgage obligations | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	379,946	407,911
Single issuer trust preferred securities issued by banks
ASSETS
Debt Securities, Held-to-maturity	[4]	1,500	1,500
Held to Maturity, Fair Value, Total	[4]	1,372	1,373
Single issuer trust preferred securities issued by banks | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	1,372	1,373
Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Held-to-maturity	[4]	127,201	130,426
Held to Maturity, Fair Value, Total	[4]	118,872	124,653
Small Business Administration Pooled Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Held to Maturity, Fair Value, Total	[4]	0	0
Small Business Administration Pooled Securities [Member] | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	118,872	124,653
Small Business Administration Pooled Securities [Member] | Significant Unobservable Inputs (Level 3)
ASSETS
Held to Maturity, Fair Value, Total	[4]	0	0
Loans, net of allowance for credit losses (b)
ASSETS
Loans, net of allowance for credit losses (b)	[5]	14,224,230	14,106,967
Loans Receivable, Fair Value Disclosure	[5]	13,149,417	13,079,368
Loans, net of allowance for credit losses (b) | Significant Unobservable Inputs (Level 3)
ASSETS
Loans Receivable, Fair Value Disclosure	[5]	13,149,417	13,079,368
Investment in Federal Home Loan Bank Stock [Member]
ASSETS
Federal Home Loan Bank Stock	[6]	32,738	43,557
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	32,738	43,557
Investment in Federal Home Loan Bank Stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	0	0
Investment in Federal Home Loan Bank Stock [Member] | Significant Other Observable Inputs (Level 2)
ASSETS
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	32,738	43,557
Investment in Federal Home Loan Bank Stock [Member] | Significant Unobservable Inputs (Level 3)
ASSETS
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	0	0
Cash Surrender Value [Member]
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	300,111	297,387
Bank Owned Life Insurance	[7]	300,111	297,387
Cash Surrender Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	0	0
Cash Surrender Value [Member] | Significant Other Observable Inputs (Level 2)
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	300,111	297,387
Cash Surrender Value [Member] | Significant Unobservable Inputs (Level 3)
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	$ 0	$ 0

[1] Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date.

[2] Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities.

[3] Fair value was determined based upon market prices of securities with similar terms and maturities.

[4] The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis.

[5] Fair value of loans is measured using the exit price valuation method, determined primarily by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows, while incorporating liquidity and credit assumptions. Additionally, this amount excludes individually assessed collateral dependent loans, which are deemed to be marked to fair value on a nonrecurring basis.

[6] Federal Home Loan Bank stock has no quoted market value and is carried at cost; therefore, the carrying amount approximates fair value.

[7] Cash surrender value of life insurance policies is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore, carrying amount approximates fair value.