Consolidated Statements of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
OPERATING REVENUE
Rental	$ 138,934	$ 104,716
Operating expense reimbursement	58,681	42,411
Total operating revenue	197,615	147,127
OPERATING EXPENSE
Rental property	38,561	25,229
Real estate taxes	24,501	17,957
General and administrative	18,361	19,793
Depreciation and amortization	56,734	37,220
Total operating expenses	138,157	100,199
Operating income	59,458	46,928
OTHER INCOME (EXPENSE)
Other income	2,452	4,373
Interest expense	(39,207)	(27,739)
Total other income (expense)	(36,755)	(23,366)
Income before income taxes and equity in earnings of unconsolidated joint ventures	22,703	23,562
Income taxes	(531)	(491)
Equity in earnings of unconsolidated joint ventures	4,159	1,757
Income from continuing operations	26,331	24,828
Discontinued operations (including net gain on property dispositions of $46,117 and $41,713 for the three months ended March 31, 2014 and 2013, respectively)	47,775	49,828
Net income	74,106	74,656
Noncontrolling interest – operating partnership	(1,853)	(3,417)
Noncontrolling interest - consolidated joint ventures	(353)	0
Net income available to common shareholders	71,900	71,239
Comprehensive income attributable to common shareholders
Net income	74,106	74,656
Other comprehensive income (loss) - foreign currency translation	1,346	(4,851)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(511)	0
Other Comprehensive Income (Loss), Net of Tax	835	(4,851)
Total comprehensive income	74,941	69,805
Less: comprehensive income attributable to noncontrolling interest	(2,226)	(3,271)
Comprehensive income attributable to common shareholders	72,715	66,534
Basic:
Income from continuing operations	$ 0.17	$ 0.19
Income from discontinued operations	$ 0.32	$ 0.41
Income per common share - basic	$ 0.49	$ 0.60
Diluted:
Income from continuing operations	$ 0.17	$ 0.19
Income from discontinued operations	$ 0.32	$ 0.41
Income per common share - diluted	$ 0.49	$ 0.60
Distributions per common share or unit	$ 0.475	$ 0.475
Weighted average number of common shares outstanding
Basic	146,425	118,688
Diluted	147,095	119,532
Amounts attributable to common shareholders
Income from continuing operations	25,250	22,908
Discontinued operations	46,650	48,331
Net income available to common shareholders	71,900	71,239
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	138,934	104,716
Operating expense reimbursement	58,681	42,411
Total operating revenue	197,615	147,127
OPERATING EXPENSE
Rental property	38,561	25,229
Real estate taxes	24,501	17,957
General and administrative	18,361	19,793
Depreciation and amortization	56,734	37,220
Total operating expenses	138,157	100,199
Operating income	59,458	46,928
OTHER INCOME (EXPENSE)
Other income	2,452	4,373
Interest expense	(39,207)	(27,739)
Total other income (expense)	(36,755)	(23,366)
Income before income taxes and equity in earnings of unconsolidated joint ventures	22,703	23,562
Income taxes	(531)	(491)
Equity in earnings of unconsolidated joint ventures	4,159	1,757
Income from continuing operations	26,331	24,828
Discontinued operations (including net gain on property dispositions of $46,117 and $41,713 for the three months ended March 31, 2014 and 2013, respectively)	47,775	49,828
Net income	74,106	74,656
Noncontrolling interest - consolidated joint ventures	(353)	0
Preferred unit distributions	(118)	(1,211)
Net income available to common shareholders	73,635	73,445
Comprehensive income attributable to common shareholders
Net income	74,106	74,656
Other comprehensive income (loss) - foreign currency translation	1,346	(4,851)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(511)	0
Other Comprehensive Income (Loss), Net of Tax	835	(4,851)
Total comprehensive income	74,941	69,805
Basic:
Income from continuing operations	$ 0.17	$ 0.19
Income from discontinued operations	$ 0.32	$ 0.41
Income per common share - basic	$ 0.49	$ 0.60
Diluted:
Income from continuing operations	$ 0.17	$ 0.19
Income from discontinued operations	$ 0.32	$ 0.41
Income per common share - diluted	$ 0.49	$ 0.60
Distributions per common share or unit	$ 0.475	$ 0.475
Weighted average number of common shares outstanding
Basic	149,981	122,402
Diluted	150,651	123,246
Net income allocated to general partners	71,900	71,239
Net income allocated to limited partners	1,853	3,417
Amounts attributable to common shareholders
Income from continuing operations	25,978	24,828
Net income available to common shareholders	$ 73,635	$ 73,445