Consolidated Statement of Equity - USD ($)	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 income - foreign currency translation	$ (23,003,000)								$ (23,003,000)
Other comprehensive income - derivative instruments	(1,132,000)								(1,132,000)
Beginning Balance at Dec. 31, 2016	$ 3,062,923,000	$ 147,000	$ 3,655,910,000	$ (56,031,000)	$ (596,635,000)	$ 3,003,391,000	$ 54,631,000	$ 4,901,000	$ 3,062,923,000	$ 3,003,391,000	$ 54,631,000	$ 4,901,000
Common shares outstanding - Beginning Balance (shares) at Dec. 31, 2016	146,993,018								146,993,018				146,993,018
General Partner's units outstanding - Beginning Balance (units) at Dec. 31, 2016														146,993,018
Limited Partners' units outstanding - Beginning Balance (units) at Dec. 31, 2016	3,530,031								3,530,031						3,530,031
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares	$ 7,356,000		7,356,000			7,356,000
Net proceeds from issuance of common shares (shares)													404,496
Net income	157,867,000				153,982,000	153,982,000	3,690,000	195,000	$ 157,867,000	153,982,000	3,690,000	195,000
Contributions from partners									15,821,000	15,821,000
Contributions from partners (units)														404,496
Distributions	(181,294,000)				(176,697,000)	(176,697,000)	(4,159,000)	(438,000)
Distributions to partners									(181,294,000)	(176,697,000)	(4,159,000)	(438,000)
Share-based compensation	8,465,000		8,465,000			8,465,000
Other comprehensive income - foreign currency translation	16,314,000			15,932,000		15,932,000	382,000		16,314,000	15,932,000	382,000
Other comprehensive income - derivative instruments	366,000			358,000		358,000	8,000		$ 366,000	358,000	8,000
Redemption of noncontrolling interests	$ 0		27,000			27,000	(27,000)
Redemption of limited partners common units for common shares - common units (shares)													1,750	1,750
Redemption of limited partners common units for common shares - common units										(27,000)	27,000
Partners' Capital Account, Units, Converted															(1,750)
Common shares outstanding - Ending Balance (shares) at Sep. 30, 2017	147,399,264								147,399,264				147,399,264
General Partner's units outstanding - Ending Balance (units) at Sep. 30, 2017														147,399,264
Limited Partners' units outstanding - Ending Balance (units) at Sep. 30, 2017	3,528,281								3,528,281						3,528,281
Ending Balance at Sep. 30, 2017	$ 3,071,997,000	$ 147,000	$ 3,671,758,000	$ (39,741,000)	$ (619,350,000)	$ 3,012,814,000	$ 54,525,000	$ 4,658,000	$ 3,071,997,000	$ 3,012,814,000	$ 54,525,000	$ 4,658,000
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2016	7,537,000								7,537,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (Mezzanine)	354,000								354,000
Distributions (Mezzanine)	(354,000)								(354,000)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Sep. 30, 2017	$ 7,537,000								$ 7,537,000