Income Taxes - Additional Information (Details) - USD ($)		12 Months Ended
	Jan. 01, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Examination [Line Items]
Deferred income tax (benefit) expense		$ 0
Unrealized losses on investments in debt and equity		10,642,000	$ 0
Postretirement benefit obligations		1,500,000	1,600,000
Unrealized gains on available-for-sale securities		0	18,997,000
Deferred tax asset		38,968,000	49,212,000
Unrecognized tax benefits		0
Excess income tax benefits (expense) from stock compensation		400,000	(100,000)	$ 2,000,000
Income tax credit and deferred tax asset	$ 8,500,000
Tax benefit from CARES Act		1,700,000
Amortization of low-income housing credit investments reflected as income tax expense		3,600,000	3,300,000	$ 3,000,000
Affordable housing tax benefits		700,000
Carrying value of investment in affordable housing credits		39,600,000	$ 26,600,000
General Business Tax Credit Carryforward
Income Tax Examination [Line Items]
Tax credit		3,500,000
Federal
Income Tax Examination [Line Items]
Net operating loss carryforwards		500,000
Federal net operating loss		100,000
Beneficial
Income Tax Examination [Line Items]
Unrecognized tax benefits		$ 1,700,000