CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 80,002	$ 31,530	$ 145,055	$ 115,398
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation			73,054	69,397
Amortization of Debt Issuance Costs	805	850	2,430	2,550
Other Amortization, including Stock Based Compensation			21,226	20,516
Impairment of Real Estate	0	0	0	2,756
Provision for Bad Debt			0	267
Equity in (Income) Loss of Joint Venture	72	197	(16,288)	199
Distributions from Joint Venture			16,012	0
Gain on Sale of Real Estate	(52,489)	(8,135)	(53,378)	(53,291)
Loss from Retirement of Debt	0	0	0	39
Payments to Settle Derivative Instruments	0	0	(3,149)	0
Straight-line Rental Income and Expense, Net			(7,321)	(1,329)
Increase in Tenant Accounts Receivable, Prepaid Expenses and Other Assets, Net and Operating Lease Right-of-Use Assets			(8,325)	(5,639)
Increase in Accounts Payable, Accrued Expenses, Other Liabilities, Rents Received in Advance and Security Deposits and Operating Lease Liabilities			20,863	172
Net Cash Provided by Operating Activities			190,179	151,035
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of Real Estate			(108,468)	(91,799)
Additions to Investment in Real Estate and Non-Acquisition Tenant Improvements and Lease Costs			(211,424)	(168,681)
Net Proceeds from Sales of Investments in Real Estate			102,758	116,166
Contributions to and Investments in Joint Venture			0	25,190
Distributions from Joint Venture			8,658	1,829
Other Investing Activity			(6,459)	(4,825)
Net Cash Used in Investing Activities			(214,935)	(172,500)
CASH FLOWS FROM FINANCING ACTIVITIES:
Financing and Equity Issuance Costs			(953)	(2,975)
Proceeds from Issuance of Common Stock			0	145,584
Tax Paid on Shares Withheld			(4,384)	(6,020)
Common Stock Dividends and Unit Distributions Paid			(87,490)	(81,605)
Repayments on Mortgage Loans Payable			(116,518)	(163,792)
Proceeds from Senior Unsecured Notes			150,000	300,000
Proceeds from Unsecured Credit Facility			295,000	217,000
Repayments on Unsecured Credit Facility			(217,000)	(361,500)
Net Cash Provided by Financing Activities			18,655	46,692
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash			(6,101)	25,227
Cash, Cash Equivalents and Restricted Cash, Beginning of Year			50,373	46,482
Cash, Cash Equivalents and Restricted Cash, End of Period	44,272	71,709	44,272	71,709
SUPPLEMENTAL INFORMATION TO STATEMENTS OF CASH FLOWS:
Interest Expense Capitalized in Connection with Development Activity			4,161	4,867
Cash Paid for Operating Lease Liabilities			1,273	0
Supplemental Schedule of Non-Cash Operating Activities:
Operating Lease Liabilities Arising from Obtaining Right-of-Use Assets			22,871	0
Supplemental Schedule of Non-Cash Investing and Financing Activities:
Dividends and Distributions Payable	30,386	28,749	30,386	28,749
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	0	0	0
Lease Reclassification from Operating Lease to Sales Type Lease:
Land	(933,203)		(933,203)
Deferred Rent Receivable, Net	(76,212)		(76,212)
Assumption of Indebtedness and Other Liabilities in Connection with the Acquisition of Real Estate			692	11,707
Accounts Payable Related to Construction in Progress and Additions to Investment in Real Estate			57,872	31,288
Write-off of Fully Depreciated Assets			(26,115)	(33,047)
Sales Type Lease
Lease Reclassification from Operating Lease to Sales Type Lease:
Lease Receivable	54,521	0	54,521	0
Land	(24,803)	0	(24,803)	0
Building, Net Of Accumulated Depreciation	(17,845)	0	(17,845)	0
Deferred Rent Receivable, Net	(2,073)	0	(2,073)	0
Other Assets, Net Of Accumulated Amortization	(1,194)	0	(1,194)	0
Sales-type Lease, Selling Profit (Loss)	8,606		8,606	0
Noncontrolling Interest
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	1,691	619
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	(6,861)	(4,182)	(6,861)	(16,509)
Common Stock
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	5	3	5	13
Additional Paid-in- Capital
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	6,856	4,179	6,856	16,496
First Industrial, L.P.
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	80,002	31,530	145,055	115,398
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation			73,054	69,397
Amortization of Debt Issuance Costs	805	850	2,430	2,550
Other Amortization, including Stock Based Compensation			21,226	20,516
Impairment of Real Estate	0	0	0	2,756
Provision for Bad Debt			0	267
Equity in (Income) Loss of Joint Venture	72	197	(16,288)	199
Distributions from Joint Venture			16,012	0
Gain on Sale of Real Estate	(52,489)	(8,135)	(53,378)	(53,291)
Loss from Retirement of Debt	0	0	0	39
Payments to Settle Derivative Instruments	0	0	(3,149)	0
Straight-line Rental Income and Expense, Net			(7,321)	(1,329)
Increase in Tenant Accounts Receivable, Prepaid Expenses and Other Assets, Net and Operating Lease Right-of-Use Assets			(8,240)	(5,679)
Increase in Accounts Payable, Accrued Expenses, Other Liabilities, Rents Received in Advance and Security Deposits and Operating Lease Liabilities			20,863	172
Net Cash Provided by Operating Activities			190,264	150,995
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of Real Estate			(108,468)	(91,799)
Additions to Investment in Real Estate and Non-Acquisition Tenant Improvements and Lease Costs			(211,424)	(168,681)
Net Proceeds from Sales of Investments in Real Estate			102,758	116,166
Contributions to and Investments in Joint Venture			0	25,190
Distributions from Joint Venture			8,658	1,829
Other Investing Activity			(6,459)	(4,825)
Net Cash Used in Investing Activities			(214,935)	(172,500)
CASH FLOWS FROM FINANCING ACTIVITIES:
Financing and Equity Issuance Costs			(953)	(2,975)
Proceeds from Issuance of Common Stock			0	145,584
Tax Paid on Shares Withheld			(4,384)	(6,020)
Common Stock Dividends and Unit Distributions Paid			(87,490)	(81,605)
Contributions from Noncontrolling Interests			10	124
Distributions to Noncontrolling Interests			(95)	(84)
Repayments on Mortgage Loans Payable			(116,518)	(163,792)
Proceeds from Senior Unsecured Notes			150,000	300,000
Proceeds from Unsecured Credit Facility			295,000	217,000
Repayments on Unsecured Credit Facility			(217,000)	(361,500)
Net Cash Provided by Financing Activities			18,570	46,732
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash			(6,101)	25,227
Cash, Cash Equivalents and Restricted Cash, Beginning of Year			50,373	46,482
Cash, Cash Equivalents and Restricted Cash, End of Period	44,272	71,709	44,272	71,709
SUPPLEMENTAL INFORMATION TO STATEMENTS OF CASH FLOWS:
Interest Expense Capitalized in Connection with Development Activity			4,161	4,867
Cash Paid for Operating Lease Liabilities			1,273	0
Supplemental Schedule of Non-Cash Operating Activities:
Operating Lease Liabilities Arising from Obtaining Right-of-Use Assets			22,871	0
Supplemental Schedule of Non-Cash Investing and Financing Activities:
Dividends and Distributions Payable	30,386	28,749	30,386	28,749
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	0	0	0	0
Lease Reclassification from Operating Lease to Sales Type Lease:
Land	(933,203)		(933,203)
Deferred Rent Receivable, Net	(76,212)		(76,212)
Assumption of Indebtedness and Other Liabilities in Connection with the Acquisition of Real Estate			692	11,707
Accounts Payable Related to Construction in Progress and Additions to Investment in Real Estate			57,872	31,288
Write-off of Fully Depreciated Assets			(26,115)	(33,047)
First Industrial, L.P. | Sales Type Lease
Lease Reclassification from Operating Lease to Sales Type Lease:
Lease Receivable	54,521	0	54,521	0
Land	(24,803)	0	(24,803)	0
Building, Net Of Accumulated Depreciation	(17,845)	0	(17,845)	0
Deferred Rent Receivable, Net	(2,073)	0	(2,073)	0
Other Assets, Net Of Accumulated Amortization	(1,194)	0	(1,194)	0
Sales-type Lease, Selling Profit (Loss)			8,606	0
First Industrial, L.P. | Limited Partner Units
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	1,691	619
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	(6,861)	(4,182)	(6,861)	(16,509)
First Industrial, L.P. | General Partner Units
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	78,278	30,889
Exchange of Limited Partnership Units for Common Stock/General Partnership Units:
Conversion of Limited Partner Units to Common Stock / General Partner Units	$ 6,861	$ 4,182	$ 6,861	$ 16,509