Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 26, 2018
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Trading Symbol	FR
Entity Registrant Name	FIRST INDUSTRIAL REALTY TRUST INC
Entity Central Index Key	0000921825
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		125,984,144
First Industrial, L.P.
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Trading Symbol	FRFI
Entity Registrant Name	FIRST INDUSTRIAL LP
Entity Central Index Key	0001033128
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer