Parent Company Only Financial Statements - Schedule of Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash	$ 15,728	$ 9,124
Interest-bearing deposits in other banks	108,825	37,203
Other assets	13,159	13,992
Total assets	867,173	722,171
Liabilities and Shareholders' Equity
Junior subordinated debt	4,124	4,124
Other liabilities	11,863	12,075
Total liabilities	794,712	655,049
Shareholders’ Equity
Common stock and additional paid-in capital	16,369	15,964
Retained earnings	53,767	49,787
Accumulated other comprehensive income	2,325	1,371
Total shareholders’ equity	72,461	67,122	$ 60,007	$ 56,142
Total liabilities and shareholders’ equity	867,173	722,171
Fauquier Bankshares, Inc [Member]
Assets
Cash	733	598
Interest-bearing deposits in other banks	570	330
Investment in subsidiaries	75,588	70,313
Other assets	243	171
Total assets	77,134	71,412
Liabilities and Shareholders' Equity
Junior subordinated debt	4,124	4,124
Other liabilities	549	166
Total liabilities	4,673	4,290
Shareholders’ Equity
Common stock and additional paid-in capital	16,369	15,964
Retained earnings	53,767	49,787
Accumulated other comprehensive income	2,325	1,371
Total shareholders’ equity	72,461	67,122
Total liabilities and shareholders’ equity	$ 77,134	$ 71,412