Income Taxes - Reconciliation of Federal Statutory Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Statutory to Effective Tax Rates [Abstract]
Computed “expected” tax expense	$ 1,458	$ 1,643	$ 1,445
Changes in income taxes resulting from:
Tax-exempt interest income	(160)	(146)	(149)
Tax credits	(479)	(552)	(504)
Other	248	59	(46)
Provision for income taxes	$ 1,067	$ 1,004	$ 746