Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 01, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	BAYK
Entity Registrant Name	BAY BANKS OF VIRGINIA INC
Entity Central Index Key	0001034594
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity File Number	0-22955
Entity Tax Identification Number	54-1838100
Entity Address, Address Line One	1801 BAYBERRY COURT
Entity Address, Address Line Two	SUITE 101
Entity Address, City or Town	RICHMOND
Entity Address, Postal Zip Code	23226
City Area Code	804
Local Phone Number	325-3775
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Address, State or Province	VA
Entity Common Stock, Shares Outstanding		13,334,506
Entity Incorporation, State or Country Code	VA
Document Quarterly Report	true
Document Transition Report	false