Investment Securities - Schedule of Amortized Cost of Securities and Fair Values (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	$ 1,648,280,000	$ 1,658,779,000
Gross unrealized gains	190,000	840,000
Gross unrealized losses	(183,788,000)	(187,646,000)
Allowance for credit losses for investments	0	0
Fair Value	1,464,682,000	1,471,973,000
U.S. government agency securities
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	416,953,000	204,663,000
Gross unrealized gains	145,000	470,000
Gross unrealized losses	(1,171,000)	(1,177,000)
Allowance for credit losses for investments	0	0
Fair Value	415,927,000	203,956,000
Mortgage-backed securities - residential
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	984,473,000	1,057,389,000
Gross unrealized gains	0	0
Gross unrealized losses	(158,259,000)	(160,418,000)
Allowance for credit losses for investments	0	0
Fair Value	826,214,000	896,971,000
Mortgage-backed securities - commercial
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	17,899,000	18,186,000
Gross unrealized gains	0	0
Gross unrealized losses	(1,284,000)	(1,225,000)
Allowance for credit losses for investments	0	0
Fair Value	16,615,000	16,961,000
Municipal securities
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	194,470,000	263,312,000
Gross unrealized gains	45,000	370,000
Gross unrealized losses	(22,843,000)	(21,419,000)
Allowance for credit losses for investments	0	0
Fair Value	171,672,000	242,263,000
U.S. Treasury securities
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	30,985,000	111,729,000
Gross unrealized gains	0	0
Gross unrealized losses	(128,000)	(3,233,000)
Allowance for credit losses for investments	0	0
Fair Value	30,857,000	108,496,000
Corporate securities
Debt Securities, Available-for-sale [Abstract]
Total AFS debt securities	3,500,000	3,500,000
Gross unrealized gains	0	0
Gross unrealized losses	(103,000)	(174,000)
Allowance for credit losses for investments	0	0
Fair Value	$ 3,397,000	$ 3,326,000

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: