Nature of Operations - Additional Information (Details) $ / shares in Units, $ in Millions		3 Months Ended
	Jan. 20, 2021 USD ($) $ / shares shares	Mar. 31, 2021 shares	Mar. 31, 2020 shares	Sep. 30, 2020
Basis Of Presentation [Line Items]
Sale of stock, gross proceeds	$ 37.1
Sale of stock, number of common stock issued | shares	3,701,509
Sale of stock, price per share | $ / shares	$ 10.00
Cash contributions to Employee Stock Ownership Plan ("ESOP")	$ 3.0
Employee stock ownership plan per share | $ / shares	$ 10.00
Offering expenses	$ 1.7
Amount invested in bank operations	$ 16.3
Common stock exchange ratio	0.90686
Options to purchase shares excluded from calculation of diluted earnings per common share | shares		190,928	90,441
Community First Bancshares, MHC
Basis Of Presentation [Line Items]
Common stock ownership percentage	54.00%			54.00%