Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2018
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Ending Balance	$ 7,435	$ 7,400
Finite-Lived Intangible Assets, Net, Ending Balance	$ 707
Core Deposits [Member]
Goodwill And Other Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Finite-Lived Intangible Assets, Net, Ending Balance			$ 2,000
The Peoples Bank [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Ending Balance			$ 7,400