Fair Value of Assets and Liabilities - Schedule of Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	$ 455,900	$ 476,647
FHLB stock	37,125	41,363
Bank-owned life insurance	163,700	160,790
Deposits	17,424,169	18,974,359
FHLB advances	17,189	12,787
Escrow deposits of borrowers	24,947	22,314
Interest rate swap collateral funds	16,900	14,430
Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	260,271	276,493
Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	195,629	200,154
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	0	0
FHLB stock	0	0
Bank-owned life insurance	0	0
Deposits	0	0
FHLB advances	0	0
Escrow deposits of borrowers	0	0
Interest rate swap collateral funds	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	0	0
FHLB stock	37,125	41,363
Bank-owned life insurance	163,700	160,790
Deposits	17,412,731	18,960,407
FHLB advances	670,747	702,954
Escrow deposits of borrowers	24,947	22,314
Interest rate swap collateral funds	16,900	14,430
Significant Other Observable Inputs (Level 2) \| Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	219,548	246,343
Significant Other Observable Inputs (Level 2) \| Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	168,106	176,883
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	13,099,665	13,149,096
FHLB stock	0	0
Bank-owned life insurance	0	0
Deposits	0	0
FHLB advances	0	0
Escrow deposits of borrowers	0	0
Interest rate swap collateral funds	0	0
Significant Unobservable Inputs (Level 3) \| Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Significant Unobservable Inputs (Level 3) \| Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Carrying Value
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	13,744,822	13,420,317
FHLB stock	37,125	41,363
Bank-owned life insurance	163,700	160,790
Deposits	17,424,169	18,974,359
FHLB advances	673,525	704,084
Escrow deposits of borrowers	24,947	22,314
Interest rate swap collateral funds	16,900	14,430
Carrying Value \| Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	260,271	276,493
Carrying Value \| Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	195,629	200,154
Estimate of Fair Value Measurement
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	13,099,665	13,149,096
FHLB stock	37,125	41,363
Bank-owned life insurance	163,700	160,790
Deposits	17,412,731	18,960,407
FHLB advances	670,747	702,954
Escrow deposits of borrowers	24,947	22,314
Interest rate swap collateral funds	16,900	14,430
Estimate of Fair Value Measurement \| Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	219,548	246,343
Estimate of Fair Value Measurement \| Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	$ 168,106	$ 176,883

Escrow deposits of borrowers.

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Fair value assets and liabilities measured on recurring basis [Line Items].

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Interest Rate Swap Collateral Funds

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The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy.

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Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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