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 income - foreign currency translation activity	$ 3,177								$ 3,177
Other comprehensive income - derivative instruments activity	$ 313								$ 313
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	$ 3,267	1	3,266			3,267
Net proceeds from issuance of common shares (shares)													322,450
Net income	143,607				140,181	140,181	3,339	87	$ 143,607	140,181	3,339	87
Contributions from partners									8,683	8,683
Contributions from partners (units)														322,450
Distributions	(60,685)				(59,094)	(59,094)	(1,506)	(85)
Distributions to partners									(60,685)	(59,094)	(1,506)	(85)
Share-based compensation	5,416		5,416			5,416
Other comprehensive income - foreign currency translation activity	7,932			7,747		7,747	185		7,932	7,747	185
Other comprehensive income - derivative instruments activity	$ 385			376		376	9		$ 385	376	9
Common shares outstanding - Ending Balance (shares) at Mar. 31, 2018	147,773,141								147,773,141				147,773,141
General Partner's units outstanding - Ending Balance (units) at Mar. 31, 2018														147,773,141
Limited Partners' units outstanding - Ending Balance (units) at Mar. 31, 2018	3,520,205								3,520,205						3,520,205
Ending Balance at Mar. 31, 2018	$ 3,248,288	$ 148	$ 3,683,660	$ (29,674)	$ (468,883)	$ 3,185,251	$ 58,186	$ 4,851	$ 3,248,288	$ 3,185,251	$ 58,186	$ 4,851
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)	118								118
Distributions (Mezzanine)	(118)								(118)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Mar. 31, 2018	$ 7,537								$ 7,537