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 Income (Loss)	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 Income (Loss)	First Industrial, L.P. Noncontrolling Interests
Beginning Balance at Dec. 31, 2017	$ 1,475,877	$ 1,199	$ 1,967,110	$ (541,847)	$ 1,338	$ 48,077
Beginning Balance at Dec. 31, 2017							$ 1,485,995	$ 1,401,583	$ 82,251	$ 1,382	$ 779
Increase (Decrease) in Stockholders' Equity / Partners' Capital [Roll Forward]
Net Income	167,334			163,239		4,095	167,334	163,151	4,095		88
Other Comprehensive Income (Loss)	2,192				2,138	54	2,192			2,192
Issuance of Common Stock / Contribution of General Partner Units, Net of Issuance Costs	145,408	48	145,360				145,408	145,408
Stock Based Compensation Activity	1,512	3	4,791	(3,282)
Stock Based Compensation Activity							1,512	1,512
Common Stock Dividends and Unit Distributions	(111,478)			(108,917)		(2,561)
Unit Distributions							(111,478)	(108,917)	(2,561)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	13	16,592			(16,605)	0	16,605	(16,605)
Retirement of Limited Partner Units	(934)					(934)	(934)		(934)
Reallocation—Additional Paid-in-Capital	0		(2,297)			2,297
Contributions from Noncontrolling Interests							126				126
Distributions to Noncontrolling Interests							(136)				(136)
Reallocation—Other Comprehensive Income	0				26	(26)
Ending Balance at Dec. 31, 2018	1,679,911	1,263	2,131,556	(490,807)	3,502	34,397
Ending 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	243,881			238,775		5,106	243,881	238,522	5,106		253
Other Comprehensive Income (Loss)	(10,587)				(10,365)	(222)	(10,587)			(10,587)
Stock Based Compensation Activity	4,580	2	4,397	(1,696)		1,877
Stock Based Compensation Activity							4,580	2,703	1,877
Common Stock Dividends and Unit Distributions	(119,522)			(117,107)		(2,415)
Unit Distributions							(119,522)	(117,107)	(2,415)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	5	7,191			(7,196)	0	7,196	(7,196)
Reallocation—Additional Paid-in-Capital	0		(2,297)			2,297
Contributions from Noncontrolling Interests							32				32
Distributions to Noncontrolling Interests							(119)				(119)
Reallocation—Other Comprehensive Income	0				(20)	20
Ending Balance at Dec. 31, 2019	1,798,263	1,270	2,140,847	(370,835)	(6,883)	33,864
Ending 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	200,169			195,989		4,180	200,169	195,745	4,189		235
Other Comprehensive Income (Loss)	(10,295)				(10,079)	(216)	(10,295)			(10,295)
Issuance of Common Stock / Contribution of General Partner Units, Net of Issuance Costs	78,349	18	78,331				78,349	78,349
Stock Based Compensation Activity	7,456	0	3,243	(2,975)		7,188
Stock Based Compensation Activity							7,456	268	7,188
Common Stock Dividends and Unit Distributions	(130,943)			(128,473)		(2,470)
Unit Distributions							(130,943)	(128,473)	(2,470)
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	2	2,088			(2,090)	0	2,090	(2,090)
Reallocation—Additional Paid-in-Capital	0		182			(182)
Contributions from Noncontrolling Interests	4,321					4,321	4,401				4,401
Distributions to Noncontrolling Interests							(731)				(731)
Reallocation—Other Comprehensive Income	0				9	(9)
Ending Balance at Dec. 31, 2020	$ 1,947,320	$ 1,290	$ 2,224,691	$ (306,294)	$ (16,953)	$ 44,586
Ending Balance at Dec. 31, 2020							$ 1,956,690	$ 1,898,635	$ 70,435	$ (17,308)	$ 4,928