Document and Entity Information Document	3 Months Ended
	Mar. 31, 2014	May 06, 2014
DOCUMENT AND ENTITY INFORMATION [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q1
Trading Symbol	FFBC
Entity Registrant Name	FIRST FINANCIAL BANCORP /OH/
Entity Central Index Key	0000708955
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		57,708,794