Consolidated Statement of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Accumulated Distributions in Excess of Net Income [Member]	Parent [Member]	Noncontrolling interest operating partnership Common [Member]	Noncontrolling interest-consolidated joint ventures [Member]	Liberty Property Limited Partnership [Member]	Liberty Property Limited Partnership [Member] General Partner [Member]	Liberty Property Limited Partnership [Member] Limited Partner [Member]	Liberty Property Limited Partnership [Member] Noncontrolling interest-consolidated joint ventures [Member]	Common shares [Member]	Common Units [Member] Liberty Property Limited Partnership [Member] General Partner [Member]	Common Units [Member] Liberty Property Limited Partnership [Member] Limited Partner [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss - foreign currency translation activity	$ 10,680								$ 10,680
Other comprehensive income - derivative instruments activity	$ 275								$ 275
Common shares outstanding - Beginning Balance (shares) at Dec. 31, 2017	147,450,691								147,450,691				147,450,691
Beginning Balance at Dec. 31, 2017	$ 3,148,366	$ 147	$ 3,674,978	$ (37,797)	$ (549,970)	$ 3,087,358	$ 56,159	$ 4,849	$ 3,148,366	$ 3,087,358	$ 56,159	$ 4,849
General Partner's units outstanding - Beginning Balance (units) at Dec. 31, 2017														147,450,691
Limited Partners' units outstanding - Beginning Balance (units) at Dec. 31, 2017	3,520,205								3,520,205						3,520,205
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares	$ 4,527	1	4,526			4,527
Net proceeds from issuance of common shares (shares)													345,927
Net income	164,379				159,795	159,795	3,806	778	$ 164,379	159,795	3,806	778
Contributions from partners									11,528	11,528
Contributions from partners (units)														345,927
Distributions	(121,329)				(118,211)	(118,211)	(2,914)	(204)
Distributions to partners									(121,329)	(118,211)	(2,914)	(204)
Share-based compensation	7,001		7,001			7,001
Other comprehensive loss - foreign currency translation activity	(6,206)			(6,062)		(6,062)	(144)		(6,206)	(6,062)	(144)
Other comprehensive income - derivative instruments activity	$ 487			476		476	11		$ 487	476	11
Common shares outstanding - Ending Balance (shares) at Jun. 30, 2018	147,796,618								147,796,618				147,796,618
General Partner's units outstanding - Ending Balance (units) at Jun. 30, 2018														147,796,618
Limited Partners' units outstanding - Ending Balance (units) at Jun. 30, 2018	3,520,205								3,520,205						3,520,205
Ending Balance at Jun. 30, 2018	$ 3,197,225	$ 148	$ 3,686,505	$ (43,383)	$ (508,386)	$ 3,134,884	$ 56,918	$ 5,423	$ 3,197,225	$ 3,134,884	$ 56,918	$ 5,423
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2017	7,537								7,537
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (Mezzanine)	236								236
Distributions (Mezzanine)	(236)								(236)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Jun. 30, 2018	$ 7,537								$ 7,537