Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Loss Carryforwards [Line Items]
Net unrealized losses resulting in deferred tax asset	$ 207,300,000	$ 212,700,000
Deferred tax assets from unrealized losses on certain investments in debt securities	49,446,000	50,817,000
Net deferred tax assets	102,989,000	113,232,000
Deferred tax assets	102,989,000	113,232,000
Accrual for income tax interest or penalties	0
Income tax expense (benefit) related to share-based compensation	$ 200,000	$ (500,000)	$ (1,100,000)
Investment Program Proportional Amortization Method Elected Income Tax Credit And Other Income Tax Benefit Before Amortization Statement Of Cash Flows Extensible Enumeration Not Disclosed Flag	amortization	amortization
Investment Program Proportional Amortization Method Applied Income Tax Credit And Other Tax Benefit Amortization Statement Of Cash Flows Extensible Enumeration Not Disclosed Flag	amortization	amortization
Amortization reflected as income expense related to affordable housing project investments	$ 3,200,000	$ 2,800,000	$ 2,500,000
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Provision for income tax expense	Provision for income tax expense	Provision for income tax expense
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Income or Comprehensive Income [Extensible Enumeration]	Provision for income tax expense	Provision for income tax expense	Provision for income tax expense
Affordable housing project tax credits	$ 3,000,000	$ 2,700,000	$ 2,000,000
Affordable housing project tax benefits	800,000	1,500,000	$ 1,000,000
Carrying value of affordable housing tax credits	36,300,000	39,500,000
Affordable housing tax credits, unfunded amounts	18,300,000	26,300,000
Unrecognized income tax benefits	0
U.S. Federal
Operating Loss Carryforwards [Line Items]
Net deferred tax assets	87,000,000	91,000,000
Deferred tax assets	2,400,000
State
Operating Loss Carryforwards [Line Items]
Net deferred tax assets	20,700,000	$ 22,200,000
Deferred tax assets	$ 1,200,000