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]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income - foreign currency translation	$ (18,596,000)								$ (18,596,000)
Other comprehensive income - derivative instruments	(1,795,000)								(1,795,000)
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares	4,223,000	0	4,223,000	0	0	4,223,000	0	0
Net income	96,826,000	0	0	0	94,443,000	94,443,000	2,263,000	120,000	96,826,000	94,443,000	2,263,000	120,000
Contributions from partners									10,766,000	10,766,000
Distributions	(120,810,000)	0	0	0	(117,737,000)	(117,737,000)	(2,953,000)	(120,000)
Distributions to partners									(120,810,000)	(117,737,000)	(2,953,000)	(120,000)
Share-based compensation	6,543,000	0	6,543,000	0	0	6,543,000	0	0
Other comprehensive income - foreign currency translation	10,680,000	0	0	10,430,000	0	10,430,000	250,000	0	10,680,000	10,430,000	250,000
Other comprehensive income - derivative instruments	275,000	0	0	269,000	0	269,000	6,000	0	275,000	269,000	6,000
Redemption of noncontrolling interests - common units	0	0	27,000	0	0	27,000	(27,000)	0	0	27,000	(27,000)
Ending Balance at Jun. 30, 2017	3,060,660,000	$ 147,000	$ 3,666,703,000	$ (45,332,000)	$ (619,929,000)	$ 3,001,589,000	$ 54,170,000	$ 4,901,000	3,060,660,000	$ 3,001,589,000	$ 54,170,000	$ 4,901,000
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)	236,000								236,000
Distributions (Mezzanine)	(236,000)								(236,000)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Jun. 30, 2017	$ 7,537,000								$ 7,537,000