Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING REVENUE
Rental	$ 125,203,000	$ 116,868,000
Operating expense reimbursement	38,610,000	37,413,000
Development service fee income	26,352,000	11,485,000
Total operating revenue	190,165,000	165,766,000
OPERATING EXPENSE
Rental property	15,931,000	17,535,000
Real estate taxes	23,498,000	21,906,000
General and administrative	18,628,000	16,993,000
Expensed pursuit costs	324,000	32,000
Systems implementation expense	706,000	0
Depreciation and amortization	43,686,000	43,092,000
Development service fee expense	28,067,000	11,004,000
Total operating expenses	130,840,000	110,562,000
Operating income	59,325,000	55,204,000
OTHER INCOME (EXPENSE)
Interest and other income	2,486,000	1,862,000
Interest expense	(22,750,000)	(21,634,000)
Total other income (expense)	(20,264,000)	(19,772,000)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures	39,061,000	35,432,000
Gain on property dispositions	4,121,000	807,000
Income taxes	(554,000)	(622,000)
Equity in earnings of unconsolidated joint ventures	6,764,000	5,731,000
Income from continuing operations	49,392,000	41,348,000
Discontinued operations (including net gain on property dispositions of $90.0 million for the three months ended March 31, 2018)	94,333,000	2,896,000
Net income	143,725,000	44,244,000
Noncontrolling interest – operating partnership	(3,457,000)	(1,149,000)
Noncontrolling interest - consolidated joint ventures	(87,000)	(63,000)
Net income available to common shareholders	140,181,000	43,032,000
Comprehensive income attributable to common shareholders
Net income	143,725,000	44,244,000
Other comprehensive income - foreign currency translation	7,932,000	3,177,000
Other comprehensive income - derivative instruments	385,000	313,000
Other comprehensive income	8,317,000	3,490,000
Total comprehensive income	152,042,000	47,734,000
Less: comprehensive income attributable to noncontrolling interest	(3,738,000)	(1,293,000)
Comprehensive income attributable to common shareholders	$ 148,304,000	$ 46,441,000
Weighted average number of common shares outstanding
Basic	147,060	146,471
Diluted	147,873	147,221
Amounts attributable to common shareholders
Income from continuing operations net of noncontrolling interest	$ 48,043,000	$ 40,204,000
Income from discontinued operations net of noncontrolling interest	92,138,000	2,828,000
Net income available to common shareholders	140,181,000	43,032,000
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	125,203,000	116,868,000
Operating expense reimbursement	38,610,000	37,413,000
Development service fee income	26,352,000	11,485,000
Total operating revenue	190,165,000	165,766,000
OPERATING EXPENSE
Rental property	15,931,000	17,535,000
Real estate taxes	23,498,000	21,906,000
General and administrative	18,628,000	16,993,000
Expensed pursuit costs	324,000	32,000
Systems implementation expense	706,000	0
Depreciation and amortization	43,686,000	43,092,000
Development service fee expense	28,067,000	11,004,000
Total operating expenses	130,840,000	110,562,000
Operating income	59,325,000	55,204,000
OTHER INCOME (EXPENSE)
Interest and other income	2,486,000	1,862,000
Interest expense	(22,750,000)	(21,634,000)
Total other income (expense)	(20,264,000)	(19,772,000)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures	39,061,000	35,432,000
Gain on property dispositions	4,121,000	807,000
Income taxes	(554,000)	(622,000)
Equity in earnings of unconsolidated joint ventures	6,764,000	5,731,000
Income from continuing operations	49,392,000	41,348,000
Discontinued operations (including net gain on property dispositions of $90.0 million for the three months ended March 31, 2018)	94,333,000	2,896,000
Net income	143,725,000	44,244,000
Noncontrolling interest - consolidated joint ventures	(87,000)	(63,000)
Preferred unit distributions	(118,000)	(118,000)
Net income available to common shareholders	143,520,000	44,063,000
Comprehensive income attributable to common shareholders
Net income	143,725,000	44,244,000
Other comprehensive income - foreign currency translation	7,932,000	3,177,000
Other comprehensive income - derivative instruments	385,000	313,000
Other comprehensive income	8,317,000	3,490,000
Total comprehensive income	$ 152,042,000	$ 47,734,000
Weighted average number of common shares outstanding
Basic	150,580	150,000
Diluted	151,393	150,750
Net income allocated to general partners	$ 140,181,000	$ 43,032,000
Net income allocated to limited partners	3,457,000	1,149,000
Amounts attributable to common shareholders
Income from continuing operations net of noncontrolling interest	49,305,000	41,285,000
Net income available to common shareholders	$ 143,520,000	$ 44,063,000
Common shares [Member]
Basic:
Income from continuing operations, per basic share	$ 0.33	$ 0.27
Income from discontinued operations, per basic share	0.62	0.02
Income per common share - basic	0.95	0.29
Diluted:
Income from continuing operations, per diluted share	0.33	0.27
Income from discontinued operations, per diluted share	0.62	0.02
Income per common share - diluted	0.95	0.29
Distributions per common share or unit	0.40	0.40
Common Units [Member] | Liberty Property Limited Partnership [Member]
Basic:
Income from continuing operations, per basic share	0.33	0.27
Income from discontinued operations, per basic share	0.62	0.02
Income per common share - basic	0.95	0.29
Diluted:
Income from continuing operations, per diluted share	0.33	0.27
Income from discontinued operations, per diluted share	0.62	0.02
Income per common share - diluted	0.95	0.29
Distributions per common share or unit	$ 0.40	$ 0.40