Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING REVENUE
Rental	$ 543,410	$ 584,165	$ 568,346
Operating expense reimbursement	190,357	224,608	224,285
Development service fee income	12,941	0	0
Total operating revenue	746,708	808,773	792,631
OPERATING EXPENSE
Rental property	102,481	132,702	138,124
Real estate taxes	99,793	105,410	101,814
General and administrative	68,198	68,710	63,327
Depreciation and amortization	205,090	226,575	231,943
Development service fee expense	12,165	0	0
Impairment - real estate assets	3,879	18,244	117
Total operating expense	491,606	551,641	535,325
Operating income	255,102	257,132	257,306
OTHER INCOME (EXPENSE)
Interest and other income	13,950	23,781	17,600
Loss on debt extinguishment	(27,099)	0	0
Interest expense	(115,077)	(135,779)	(151,887)
Total other income (expense)	(128,226)	(111,998)	(134,287)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures	126,876	145,134	123,019
Gain on property dispositions	219,270	100,314	45,147
Income taxes	(1,971)	(2,673)	(2,590)
Equity in earnings of unconsolidated joint ventures	21,970	3,149	10,314
Income from continuing operations	366,145	245,924	175,890
Discontinued operations (including net gain on property dispositions of $46,631 for the year ended December 31, 2014)	0	0	48,581
Net income	366,145	245,924	224,471
Noncontrolling interest – operating partnership	(9,070)	(6,192)	(5,713)
Noncontrolling interest – consolidated joint ventures	(258)	(249)	(547)
Income available to common shareholders	356,817	239,483	218,211
Comprehensive income attributable to common shareholders
Net income	366,145	245,924	224,471
Other comprehensive (loss) income - foreign currency translation	(34,744)	(12,540)	(15,671)
Other comprehensive income (loss) - derivative instruments	410	(488)	(1,961)
Other comprehensive loss	(34,334)	(13,028)	(17,632)
Total comprehensive income	331,811	232,896	206,839
Less: comprehensive income attributable to noncontrolling interest	(8,519)	(6,135)	(5,878)
Comprehensive income attributable to common shareholders	$ 323,292	$ 226,761	$ 200,961
Weighted average number of common shares outstanding
Basic (shares)	146,204	148,243	147,216
Diluted (shares)	146,889	148,843	147,886
Amounts attributable to common shareholders
Income from continuing operations	$ 356,817	$ 239,483	$ 170,772
Discontinued operations	0	0	47,439
Net income available to common shareholders	$ 356,817	$ 239,483	$ 218,211
Common shares [Member]
Basic:
Income from continuing operations (USD per share/unit)	$ 2.44	$ 1.62	$ 1.16
Income from discontinued operations (USD per share/unit)	0.00	0.00	0.32
Income per common share - basic (USD per share/unit)	2.44	1.62	1.48
Diluted:
Income from continuing operations (USD per share/unit)	2.43	1.61	1.16
Income from discontinued operations (USD per share/unit)	0.00	0.00	0.32
Income per common share - diluted (USD per share/unit)	$ 2.43	$ 1.61	$ 1.48
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	$ 543,410	$ 584,165	$ 568,346
Operating expense reimbursement	190,357	224,608	224,285
Development service fee income	12,941	0	0
Total operating revenue	746,708	808,773	792,631
OPERATING EXPENSE
Rental property	102,481	132,702	138,124
Real estate taxes	99,793	105,410	101,814
General and administrative	68,198	68,710	63,327
Depreciation and amortization	205,090	226,575	231,943
Development service fee expense	12,165	0	0
Impairment - real estate assets	3,879	18,244	117
Total operating expense	491,606	551,641	535,325
Operating income	255,102	257,132	257,306
OTHER INCOME (EXPENSE)
Interest and other income	13,950	23,781	17,600
Loss on debt extinguishment	(27,099)	0	0
Interest expense	(115,077)	(135,779)	(151,887)
Total other income (expense)	(128,226)	(111,998)	(134,287)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures	126,876	145,134	123,019
Gain on property dispositions	219,270	100,314	45,147
Income taxes	(1,971)	(2,673)	(2,590)
Equity in earnings of unconsolidated joint ventures	21,970	3,149	10,314
Income from continuing operations	366,145	245,924	175,890
Discontinued operations (including net gain on property dispositions of $46,631 for the year ended December 31, 2014)	0	0	48,581
Net income	366,145	245,924	224,471
Noncontrolling interest – consolidated joint ventures	(258)	(249)	(547)
Preferred unit distributions	(472)	(472)	(472)
Income available to common shareholders	365,415	245,203	223,452
Comprehensive income attributable to common shareholders
Net income	366,145	245,924	224,471
Other comprehensive (loss) income - foreign currency translation	(34,744)	(12,540)	(15,671)
Other comprehensive income (loss) - derivative instruments	410	(488)	(1,961)
Other comprehensive loss	(34,334)	(13,028)	(17,632)
Total comprehensive income	$ 331,811	$ 232,896	$ 206,839
Weighted average number of common shares outstanding
Basic (shares)	149,740	151,783	150,770
Diluted (shares)	150,425	152,383	151,440
Net Income Allocated to General Partners	$ 356,817	$ 239,483	$ 218,211
Net Income Allocated to Limited Partners	9,070	6,192	5,713
Amounts attributable to common shareholders
Income from continuing operations	365,887	245,675	175,343
Net income available to common shareholders	$ 365,415	$ 245,203	$ 223,452
Liberty Property Limited Partnership [Member] | Common units [Member]
Basic:
Income from continuing operations (USD per share/unit)	$ 2.44	$ 1.62	$ 1.16
Income from discontinued operations (USD per share/unit)	0.00	0.00	0.32
Income per common share - basic (USD per share/unit)	2.44	1.62	1.48
Diluted:
Income from continuing operations (USD per share/unit)	2.43	1.61	1.16
Income from discontinued operations (USD per share/unit)	0.00	0.00	0.32
Income per common share - diluted (USD per share/unit)	$ 2.43	$ 1.61	$ 1.48