Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
OPERATING REVENUE
Rental	$ 139,054,000	$ 148,585,000
Operating expense reimbursement	51,086,000	58,316,000
Total operating revenue	190,140,000	206,901,000
OPERATING EXPENSE
Rental property	28,509,000	35,571,000
Real estate taxes	25,320,000	26,164,000
General and administrative	20,990,000	18,802,000
Depreciation and amortization	54,078,000	58,796,000
Impairment - real estate assets	0	15,739,000
Total operating expenses	128,897,000	155,072,000
Operating income	61,243,000	51,829,000
OTHER INCOME (EXPENSE)
Interest and other income	4,598,000	6,371,000
Interest expense	(31,412,000)	(34,670,000)
Total other income (expense)	(26,814,000)	(28,299,000)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures	34,429,000	23,530,000
Gain on property dispositions	20,521,000	2,271,000
Income taxes	(801,000)	(845,000)
Equity in earnings of unconsolidated joint ventures	4,914,000	6,906,000
Income from continuing operations	59,063,000	31,862,000
Net income	59,063,000	31,862,000
Noncontrolling interest – operating partnership	(1,509,000)	(853,000)
Noncontrolling interest - consolidated joint ventures	0	(58,000)
Net income available to common shareholders	57,554,000	30,951,000
Comprehensive income attributable to common shareholders
Net income	59,063,000	31,862,000
Other comprehensive loss - foreign currency translation	(5,087,000)	(10,410,000)
Other comprehensive loss - derivative instruments	(1,360,000)	(947,000)
Other comprehensive loss	(6,447,000)	(11,357,000)
Total comprehensive income	52,616,000	20,505,000
Less: comprehensive income attributable to noncontrolling interest	(1,357,000)	(648,000)
Comprehensive income attributable to common shareholders	$ 51,259,000	$ 19,857,000
Weighted average number of common shares outstanding
Basic	146,071	148,315
Diluted	146,531	149,031
Amounts attributable to common shareholders
Net income available to common shareholders	$ 57,554,000	$ 30,951,000
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	139,054,000	148,585,000
Operating expense reimbursement	51,086,000	58,316,000
Total operating revenue	190,140,000	206,901,000
OPERATING EXPENSE
Rental property	28,509,000	35,571,000
Real estate taxes	25,320,000	26,164,000
General and administrative	20,990,000	18,802,000
Depreciation and amortization	54,078,000	58,796,000
Impairment - real estate assets	0	15,739,000
Total operating expenses	128,897,000	155,072,000
Operating income	61,243,000	51,829,000
OTHER INCOME (EXPENSE)
Interest and other income	4,598,000	6,371,000
Interest expense	(31,412,000)	(34,670,000)
Total other income (expense)	(26,814,000)	(28,299,000)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures	34,429,000	23,530,000
Gain on property dispositions	20,521,000	2,271,000
Income taxes	(801,000)	(845,000)
Equity in earnings of unconsolidated joint ventures	4,914,000	6,906,000
Net income	59,063,000	31,862,000
Noncontrolling interest - consolidated joint ventures	0	(58,000)
Preferred unit distributions	(118,000)	(118,000)
Net income available to common shareholders	58,945,000	31,686,000
Comprehensive income attributable to common shareholders
Net income	59,063,000	31,862,000
Other comprehensive loss - foreign currency translation	(5,087,000)	(10,410,000)
Other comprehensive loss - derivative instruments	(1,360,000)	(947,000)
Other comprehensive loss	(6,447,000)	(11,357,000)
Total comprehensive income	$ 52,616,000	$ 20,505,000
Weighted average number of common shares outstanding
Basic	149,610	151,856
Diluted	150,070	152,572
Net income allocated to general partners	$ 57,554,000	$ 30,951,000
Net income allocated to limited partners	1,509,000	853,000
Amounts attributable to common shareholders
Income from continuing operations	59,063,000	31,804,000
Net income available to common shareholders	$ 58,945,000	$ 31,686,000
Common shares [Member]
Basic:
Income per common share - basic	$ 0.39	$ 0.21
Diluted:
Income per common share - diluted	0.39	0.21
Distributions per common share or unit	0.475	0.475
Common Units [Member] | Liberty Property Limited Partnership [Member]
Basic:
Income per common share - basic	0.39	0.21
Diluted:
Income per common share - diluted	0.39	0.21
Distributions per common share or unit	$ 0.475	$ 0.475