CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS EQUITY/ PARTNER'S CAPITAL - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in- Capital	Distributions in Excess of Accumulated Earnings	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interest	First Industrial, L.P.	First Industrial, L.P. General Partner Units	First Industrial, L.P. Limited Partner Units	First Industrial, L.P. Accumulated Other Comprehensive (Loss) Income	First Industrial, L.P. Noncontrolling Interest
Beginning Balance at Dec. 31, 2018	$ 1,679,911	$ 1,263	$ 2,131,556	$ (490,807)	$ 3,502	$ 34,397
Beginning Balance at Dec. 31, 2018							$ 1,690,019	$ 1,619,342	$ 66,246	$ 3,574	$ 857
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	24,340			23,803		537	24,340	23,777	537		26
Other Comprehensive Income (Loss)	(6,330)				(6,190)	(140)	(6,330)			(6,330)
Stock Based Compensation Activity	(2,035)	2	(611)	(1,696)		270
Stock Based Compensation Activity							(2,035)	(2,305)	270
Common Stock Dividends and Unit Distributions	(29,922)			(29,258)		(664)
Unit Distributions							(29,922)	(29,258)	(664)
Reallocation - Additional Paid-in-Capital	0		(3,238)			3,238
Reallocation - Other Comprehensive Income	0				(7)	7
Distributions to Noncontrolling Interests							(43)				(43)
Ending Balance at Mar. 31, 2019	1,665,964	1,265	2,127,707	(497,958)	(2,695)	37,645
Ending Balance at Mar. 31, 2019							1,676,029	1,611,556	66,389	(2,756)	840
Beginning Balance at Dec. 31, 2018	1,679,911	1,263	2,131,556	(490,807)	3,502	34,397
Beginning Balance at Dec. 31, 2018							1,690,019	1,619,342	66,246	3,574	857
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	145,055						145,055
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	5	6,856			(6,861)	0	6,861	(6,861)
Ending Balance at Sep. 30, 2019	1,725,320	1,270	2,138,058	(438,337)	(8,444)	32,773
Ending Balance at Sep. 30, 2019							1,735,343	1,681,106	61,987	(8,605)	855
Beginning Balance at Mar. 31, 2019	1,665,964	1,265	2,127,707	(497,958)	(2,695)	37,645
Beginning Balance at Mar. 31, 2019							1,676,029	1,611,556	66,389	(2,756)	840
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	40,713			39,800		913	40,713	39,776	913		24
Other Comprehensive Income (Loss)	(4,463)				(4,362)	(101)	(4,463)			(4,463)
Stock Based Compensation Activity	2,053	0	1,542	0		511
Stock Based Compensation Activity							(2,053)	(1,542)	(511)
Common Stock Dividends and Unit Distributions	(29,864)			(29,212)		(652)
Unit Distributions							(29,864)	(29,212)	(652)
Reallocation - Additional Paid-in-Capital	0		458			(458)
Reallocation - Other Comprehensive Income	0				(1)	1
Contributions from Noncontrolling Interests							5				5
Distributions to Noncontrolling Interests							(21)				(21)
Ending Balance at Jun. 30, 2019	1,674,403	1,265	2,129,707	(487,370)	(7,058)	37,859
Ending Balance at Jun. 30, 2019							1,684,452	1,623,662	67,161	(7,219)	848
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	80,002			78,311		1,691	80,002	78,278	1,691		33
Other Comprehensive Income (Loss)	(1,386)				(1,363)	(23)	(1,386)			(1,386)
Stock Based Compensation Activity	2,131	0	1,583	0		548
Stock Based Compensation Activity							(2,131)	(1,583)	(548)
Common Stock Dividends and Unit Distributions	(29,830)			(29,278)		(552)
Unit Distributions							(29,830)	(29,278)	(552)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	5	6,856			(6,861)	0	6,861	(6,861)
Reallocation - Additional Paid-in-Capital	0		(88)			88
Reallocation - Other Comprehensive Income	0				(23)	23
Contributions from Noncontrolling Interests							5				5
Distributions to Noncontrolling Interests							(31)				(31)
Ending Balance at Sep. 30, 2019	1,725,320	1,270	2,138,058	(438,337)	(8,444)	32,773
Ending Balance at Sep. 30, 2019							1,735,343	1,681,106	61,987	(8,605)	855
Beginning Balance at Dec. 31, 2019	1,798,263	1,270	2,140,847	(370,835)	(6,883)	33,864
Beginning Balance at Dec. 31, 2019							1,808,284	1,750,656	63,618	(7,013)	1,023
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	41,529			40,634		895	41,529	40,584	895		50
Other Comprehensive Income (Loss)	(14,488)				(14,175)	(313)	(14,488)			(14,488)
Stock Based Compensation Activity	(1,835)	0	(1,233)	(2,975)		2,373
Stock Based Compensation Activity							(1,835)	(4,208)	2,373
Common Stock Dividends and Unit Distributions	(32,488)			(31,874)		(614)
Unit Distributions							(32,488)	(31,874)	(614)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	2	2,062			(2,064)	0	2,064	(2,064)
Reallocation - Additional Paid-in-Capital	0		(3,378)			3,378
Reallocation - Other Comprehensive Income	0				4	(4)
Contributions from Noncontrolling Interests							5				5
Distributions to Noncontrolling Interests							(366)				(366)
Ending Balance at Mar. 31, 2020	1,790,981	1,272	2,138,298	(365,050)	(21,054)	37,515
Ending Balance at Mar. 31, 2020							1,800,641	1,757,222	64,208	(21,501)	712
Beginning Balance at Dec. 31, 2019	1,798,263	1,270	2,140,847	(370,835)	(6,883)	33,864
Beginning Balance at Dec. 31, 2019							1,808,284	1,750,656	63,618	(7,013)	1,023
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	114,662						114,662
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	2	2,067			(2,069)	0	2,069	(2,069)
Ending Balance at Sep. 30, 2020	1,888,599	1,290	2,221,552	(357,682)	(19,969)	43,408
Ending Balance at Sep. 30, 2020							1,898,060	1,845,742	67,710	(20,388)	4,996
Beginning Balance at Mar. 31, 2020	1,790,981	1,272	2,138,298	(365,050)	(21,054)	37,515
Beginning Balance at Mar. 31, 2020							1,800,641	1,757,222	64,208	(21,501)	712
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	36,426			35,669		757	36,426	35,575	757		94
Other Comprehensive Income (Loss)	(1,282)				(1,260)	(22)	(1,282)			(1,282)
Stock Based Compensation Activity	3,108	0	1,486	0		1,622
Stock Based Compensation Activity							(3,108)	(1,486)	(1,622)
Common Stock Dividends and Unit Distributions	(32,560)			(31,929)		(631)
Unit Distributions							(32,560)	(31,929)	(631)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	0	1			(1)	0	1	(1)
Reallocation - Additional Paid-in-Capital	0		1,470			(1,470)
Reallocation - Other Comprehensive Income	0				6	(6)
Contributions from Noncontrolling Interests							12				12
Distributions to Noncontrolling Interests							(65)				(65)
Ending Balance at Jun. 30, 2020	1,796,673	1,272	2,141,255	(361,310)	(22,308)	37,764
Ending Balance at Jun. 30, 2020							1,806,280	1,762,355	65,955	(22,783)	753
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	36,707			35,959		748	36,707	35,879	760		68
Other Comprehensive Income (Loss)	2,395				2,342	53	2,395			2,395
Issuance of Common Stock, Net of Issuance Costs	78,349	18	78,331					(78,349)
Stock Based Compensation Activity	3,079	0	1,486	0		1,593
Stock Based Compensation Activity							(3,079)	(1,486)	(1,593)
Common Stock Dividends and Unit Distributions	(32,925)			(32,331)		(594)
Unit Distributions							(32,925)	(32,331)	(594)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	0	4			(4)	0	4	(4)
Reallocation - Additional Paid-in-Capital	0		476			(476)
Reallocation - Other Comprehensive Income	0				(3)	3
Contributions from Noncontrolling Interests	4,321					4,321	4,371				4,371
Distributions to Noncontrolling Interests							(196)				(196)
Ending Balance at Sep. 30, 2020	$ 1,888,599	$ 1,290	$ 2,221,552	$ (357,682)	$ (19,969)	$ 43,408
Ending Balance at Sep. 30, 2020							$ 1,898,060	$ 1,845,742	$ 67,710	$ (20,388)	$ 4,996