Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Aug. 03, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	PREMIER FINANCIAL BANCORP INC
Entity Central Index Key	0000887919
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		13,368,975
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	true
Amendment Description	This Amendment No. 1 to the Quarterly Report on Form 10-Q/A for the quarterly period ending June 30, 2018 is being filed solely to correct a typographical error on the cover page and to reflect the correct number of shares outstanding at August 3, 2018.
Document Period End Date	Jun. 30, 2018