CONSOLIDATED STATEMENT OF CHANGES IN 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 Interests	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 Interests
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 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, 2020	1,947,320	1,290	2,224,691	(306,294)	(16,953)	44,586
Beginning Balance at Dec. 31, 2020							1,956,690	1,898,635	70,435	(17,308)	4,928
Increase (Decrease) in Equity / Partners' Capital [Roll Forward]
Net Income	63,583			62,198		1,385	63,583	62,176	1,389		18
Other Comprehensive Income (Loss)	6,755				6,607	148	6,755			6,755
Stock Based Compensation Activity	(1,055)	1	(1,347)	(2,294)		2,585
Stock Based Compensation Activity							(1,055)	(3,640)	2,585
Common Stock Dividends and Unit Distributions	(35,718)			(34,933)		(785)
Unit Distributions							(35,718)	(34,933)	(785)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	0	22			(22)	0	22	(22)
Reallocation - Additional Paid-in Capital	0		(2,110)			2,110
Reallocation - Other Comprehensive Income	0				34	(34)
Contributions from Noncontrolling Interests							29				29
Distributions to Noncontrolling Interests							(24)				(24)
Ending Balance at Mar. 31, 2021	$ 1,980,885	$ 1,291	$ 2,221,256	$ (281,323)	$ (10,312)	$ 49,973
Ending Balance at Mar. 31, 2021							$ 1,990,260	$ 1,922,260	$ 73,602	$ (10,553)	$ 4,951