Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 02, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	FAUQUIER BANKSHARES, INC.
Entity Central Index Key	0001083643
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		3,784,934
Document Fiscal Year Focus	2019
Trading Symbol	FBSS
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	000-25805
Entity Tax Identification Number	541288193
Entity Address Line One	10 Courthouse Square
Entity Address Town	Warrenton
Entity Address State	Virginia
Entity Address Postal Zip Code	20186
City Area Code	540
Local Phone Number	347-2700