CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues [Abstract]
Rental Income	$ 306,406	$ 303,874	$ 289,858
Tenant Recoveries and Other Income	97,548	92,528	88,162
Total Revenues	403,954	396,402	378,020
Expenses:
Property Expenses	116,854	113,494	112,324
General and Administrative	27,749	28,079	26,703
Depreciation and Other Amortization	116,459	116,364	117,282
Impairment of Real Estate	2,756	0	0
Acquisition Costs	0	0	491
Total Expenses	263,818	257,937	256,800
Other Income (Expense):
Gain on Sale of Real Estate	81,600	131,269	68,202
Interest Expense	(50,775)	(57,199)	(59,430)
Amortization of Debt Issuance Costs	(3,404)	(3,162)	(3,219)
Settlement Gain on Derivative Instruments	0	1,896	0
Loss from Retirement of Debt	(39)	(1,775)	0
Total Other Income (Expense)	27,382	71,029	5,553
Income from Operations Before Equity in Loss of Joint Venture and Income Tax Provision	167,518	209,494	126,773
Equity in Loss of Joint Venture	(276)	0	0
Income Tax Benefit (Provision)	92	(1,193)	(1,089)
Net Income	167,334	208,301	125,684
Less: Net Income Attributable to the Noncontrolling Interest	(4,095)	(6,845)	(4,452)
Net Income Available to Common Stockholders / Unitholders and Participating Securities	$ 163,239	$ 201,456	$ 121,232
Basic Earnings Per Share / Unit:
Net Income Available to Common Stockholders/Unitholders	$ 1.31	$ 1.70	$ 1.05
Diluted Earnings Per Share / Unit:
Net Income Available to Common Stockholders/Unitholders	1.31	1.69	1.05
Dividends/Distributions Per Share/Unit	$ 0.87	$ 0.84	$ 0.76
Weighted Average Shares/Units Outstanding - Basic	123,804	118,272	115,030
Weighted Average Shares / Units Outstanding - Diluted	124,191	118,787	115,370
First Industrial, L.P.
Revenues [Abstract]
Rental Income	$ 306,406	$ 303,874	$ 289,858
Tenant Recoveries and Other Income	97,548	92,528	88,162
Total Revenues	403,954	396,402	378,020
Expenses:
Property Expenses	116,854	113,494	112,324
General and Administrative	27,749	28,079	26,703
Depreciation and Other Amortization	116,459	116,364	117,282
Impairment of Real Estate	2,756	0	0
Acquisition Costs	0	0	491
Total Expenses	263,818	257,937	256,800
Other Income (Expense):
Gain on Sale of Real Estate	81,600	131,269	68,202
Interest Expense	(50,775)	(57,199)	(59,430)
Amortization of Debt Issuance Costs	(3,404)	(3,162)	(3,219)
Settlement Gain on Derivative Instruments	0	1,896	0
Loss from Retirement of Debt	(39)	(1,775)	0
Total Other Income (Expense)	27,382	71,029	5,553
Income from Operations Before Equity in Loss of Joint Venture and Income Tax Provision	167,518	209,494	126,773
Equity in Loss of Joint Venture	(276)	0	0
Income Tax Benefit (Provision)	92	(1,193)	(1,089)
Net Income	167,334	208,301	125,684
Less: Net Income Attributable to the Noncontrolling Interest	(88)	(143)	(137)
Net Income Available to Common Stockholders / Unitholders and Participating Securities	$ 167,246	$ 208,158	$ 125,547
Basic Earnings Per Share / Unit:
Net Income Available to Common Stockholders/Unitholders	$ 1.31	$ 1.70	$ 1.05
Diluted Earnings Per Share / Unit:
Net Income Available to Common Stockholders/Unitholders	1.31	1.69	1.05
Dividends/Distributions Per Share/Unit	$ 0.87	$ 0.84	$ 0.76
Weighted Average Shares/Units Outstanding - Basic	126,921	122,306	119,274
Weighted Average Shares / Units Outstanding - Diluted	127,308	122,821	119,614