Liberty Property Limited Partnership 10-Q 4 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2015	Nov. 03, 2015
Entity Information [Line Items]
Entity Registrant Name	LIBERTY PROPERTY TRUST
Entity Central Index Key	921,112
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		147,771,561
Liberty Property Limited Partnership [Member]
Entity Information [Line Items]
Entity Registrant Name	LIBERTY PROPERTY LIMITED PARTNERSHIP
Entity Central Index Key	921,113

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Real Estate [Abstract]
Land and land improvements	$ 1,218,906	$ 1,189,760
Building and improvements	5,352,219	5,343,908
Less accumulated depreciation	(1,228,702)	(1,182,569)
Operating real estate	5,342,423	5,351,099
Development in progress	338,673	277,411
Land held for development	291,159	269,059
Net real estate	5,972,255	5,897,569
Cash and cash equivalents	48,652	69,346
Restricted cash	14,939	20,325
Accounts receivable	14,384	15,481
Deferred rent receivable	119,224	107,909
Deferred financing and leasing costs, net of accumulated amortization (2015, $180,608; 2014, $169,468)	208,623	206,286
Investments in and advances to unconsolidated joint ventures	213,894	208,832
Assets held for sale	0	8,389
Prepaid expenses and other assets	97,822	91,399
Total assets	6,689,793	6,625,536
LIABILITIES
Mortgage loans	372,660	487,301
Unsecured notes	2,608,307	2,509,094
Credit facility	300,000	167,000
Accounts payable	60,256	52,043
Accrued interest	43,771	24,513
Dividend and distributions payable	71,863	72,253
Other liabilities	218,290	219,418
Total liabilities	3,675,147	3,531,622
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2015 and December 31, 2014	7,537	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 147,753,980 and 148,557,270 shares issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	148	149
Additional paid-in capital	3,673,001	3,688,644
Accumulated other comprehensive loss	(13,837)	(6,252)
Distributions in excess of net income	(709,091)	(654,869)
Total Liberty Property Trust shareholders' equity	2,950,221	3,027,672
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	52,969	54,786
Noncontrolling interest - consolidated joint ventures	3,919	3,919
Total owners' equity	3,007,109	3,086,377
Total liabilities, noncontrolling interest - operating partnership and equity	6,689,793	6,625,536
Liberty Property Limited Partnership [Member]
Real Estate [Abstract]
Land and land improvements	1,218,906	1,189,760
Building and improvements	5,352,219	5,343,908
Less accumulated depreciation	(1,228,702)	(1,182,569)
Operating real estate	5,342,423	5,351,099
Development in progress	338,673	277,411
Land held for development	291,159	269,059
Net real estate	5,972,255	5,897,569
Cash and cash equivalents	48,652	69,346
Restricted cash	14,939	20,325
Accounts receivable	14,384	15,481
Deferred rent receivable	119,224	107,909
Deferred financing and leasing costs, net of accumulated amortization (2015, $180,608; 2014, $169,468)	208,623	206,286
Investments in and advances to unconsolidated joint ventures	213,894	208,832
Assets held for sale	0	8,389
Prepaid expenses and other assets	97,822	91,399
Total assets	6,689,793	6,625,536
LIABILITIES
Mortgage loans	372,660	487,301
Unsecured notes	2,608,307	2,509,094
Credit facility	300,000	167,000
Accounts payable	60,256	52,043
Accrued interest	43,771	24,513
Dividend and distributions payable	71,863	72,253
Other liabilities	218,290	219,418
Total liabilities	3,675,147	3,531,622
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2015 and December 31, 2014	7,537	7,537
EQUITY
General partner’s equity - 147,753,980 and 148,557,270 common units outstanding as of September 30, 2015 and December 31, 2014, respectively	2,950,221	3,027,672
Limited partners' equity	52,969	54,786
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	3,919	3,919
Total owners' equity	3,007,109	3,086,377
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,689,793	$ 6,625,536

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Deferred financing and leasing costs, accumulated amortization	$ 180,608,000	$ 169,468,000
Limited Partners' common units outstanding	3,539,075	3,553,566
Common shares of beneficial interest, par value per share	$ 0.001	$ 0.001
Common shares of beneficial interest, shares authorized	283,987,000	283,987,000
Common shares of beneficial interest, shares issued	147,753,980	148,557,270
Common shares of beneficial interest, shares outstanding	147,753,980	148,557,270
Liberty Property Limited Partnership [Member]
Deferred financing and leasing costs, accumulated amortization	$ 180,608,000	$ 169,468,000
Limited Partners' common units outstanding	3,539,075	3,553,566
Common shares of beneficial interest, shares outstanding	147,753,980	148,557,270
Series I 2 [Member]
Noncontrolling interest - operating partnership, preferred units outstanding	301,483	301,483
Series I 2 [Member] | Liberty Property Limited Partnership [Member]
Noncontrolling interest - operating partnership, preferred units outstanding	301,483	301,483

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
OPERATING REVENUE
Rental	$ 145,009,000	$ 143,294,000	$ 440,962,000	$ 421,620,000
Operating expense reimbursement	53,963,000	55,062,000	168,430,000	167,326,000
Total operating revenue	198,972,000	198,356,000	609,392,000	588,946,000
OPERATING EXPENSE
Rental property	31,454,000	33,105,000	98,973,000	103,728,000
Real estate taxes	25,953,000	25,595,000	78,579,000	75,812,000
General and administrative	15,573,000	14,748,000	51,428,000	48,077,000
Depreciation and amortization	55,718,000	58,578,000	171,347,000	173,184,000
Impairment - real estate assets	0	0	16,775,000	0
Total operating expenses	128,698,000	132,026,000	417,102,000	400,801,000
Operating income	70,274,000	66,330,000	192,290,000	188,145,000
OTHER INCOME (EXPENSE)
Other income	4,959,000	6,233,000	17,911,000	11,786,000
Interest expense	(33,559,000)	(37,958,000)	(103,295,000)	(115,635,000)
Total other income (expense)	(28,600,000)	(31,725,000)	(85,384,000)	(103,849,000)
Income before gain (loss) on property dispositions, income taxes and equity in (loss) earnings of unconsolidated joint ventures	41,674,000	34,605,000	106,906,000	84,296,000
Gain (loss) on property dispositions	53,467,000	(20,000)	56,987,000	1,878,000
Income taxes	(599,000)	(859,000)	(2,613,000)	(2,083,000)
Equity in (loss) earnings of unconsolidated joint ventures	(847,000)	1,592,000	805,000	7,297,000
Income from continuing operations	93,695,000	35,318,000	162,085,000	91,388,000
Discontinued operations (including net gain on property dispositions of $38 for the three months ended September 30, 2014 and $46,292 for the nine months ended September 30, 2014)	0	133,000	0	48,276,000
Net income	93,695,000	35,451,000	162,085,000	139,664,000
Noncontrolling interest – operating partnership	(2,306,000)	(944,000)	(4,117,000)	(3,618,000)
Noncontrolling interest - consolidated joint ventures	(58,000)	(84,000)	(171,000)	(474,000)
Net income available to common shareholders	91,331,000	34,423,000	157,797,000	135,572,000
Comprehensive income attributable to common shareholders
Net income	93,695,000	35,451,000	162,085,000	139,664,000
Other comprehensive loss - foreign currency translation	(7,970,000)	(13,000,000)	(6,229,000)	(5,189,000)
Other comprehensive (loss) income - derivative instruments	(1,220,000)	666,000	(1,539,000)	(990,000)
Other comprehensive loss	(9,190,000)	(12,334,000)	(7,768,000)	(6,179,000)
Total comprehensive income	84,505,000	23,117,000	154,317,000	133,485,000
Less: comprehensive income attributable to noncontrolling interest	(2,148,000)	(739,000)	(4,105,000)	(3,948,000)
Comprehensive income attributable to common shareholders	$ 82,357,000	$ 22,378,000	$ 150,212,000	$ 129,537,000
Weighted average number of common shares outstanding
Basic	148,582	147,422	148,594	146,987
Diluted	149,176	148,088	149,220	147,661
Amounts attributable to common shareholders
Income from continuing operations	$ 91,331,000	$ 34,293,000	$ 157,797,000	$ 88,430,000
Discontinued operations	0	130,000	0	47,142,000
Net income available to common shareholders	91,331,000	34,423,000	157,797,000	135,572,000
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	145,009,000	143,294,000	440,962,000	421,620,000
Operating expense reimbursement	53,963,000	55,062,000	168,430,000	167,326,000
Total operating revenue	198,972,000	198,356,000	609,392,000	588,946,000
OPERATING EXPENSE
Rental property	31,454,000	33,105,000	98,973,000	103,728,000
Real estate taxes	25,953,000	25,595,000	78,579,000	75,812,000
General and administrative	15,573,000	14,748,000	51,428,000	48,077,000
Depreciation and amortization	55,718,000	58,578,000	171,347,000	173,184,000
Impairment - real estate assets			16,775,000	0
Total operating expenses	128,698,000	132,026,000	417,102,000	400,801,000
Operating income	70,274,000	66,330,000	192,290,000	188,145,000
OTHER INCOME (EXPENSE)
Other income	4,959,000	6,233,000	17,911,000	11,786,000
Interest expense	(33,559,000)	(37,958,000)	(103,295,000)	(115,635,000)
Total other income (expense)	(28,600,000)	(31,725,000)	(85,384,000)	(103,849,000)
Income before gain (loss) on property dispositions, income taxes and equity in (loss) earnings of unconsolidated joint ventures	41,674,000	34,605,000	106,906,000	84,296,000
Gain (loss) on property dispositions	53,467,000	(20,000)	56,987,000	1,878,000
Income taxes	(599,000)	(859,000)	(2,613,000)	(2,083,000)
Equity in (loss) earnings of unconsolidated joint ventures	(847,000)	1,592,000	805,000	7,297,000
Income from continuing operations	93,695,000	35,318,000	162,085,000	91,388,000
Discontinued operations (including net gain on property dispositions of $38 for the three months ended September 30, 2014 and $46,292 for the nine months ended September 30, 2014)	0	133,000	0	48,276,000
Net income	93,695,000	35,451,000	162,085,000	139,664,000
Noncontrolling interest - consolidated joint ventures	(58,000)	(84,000)	(171,000)	(474,000)
Preferred unit distributions	(118,000)	(118,000)	(354,000)	(354,000)
Net income available to common shareholders	93,519,000	35,249,000	161,560,000	138,836,000
Comprehensive income attributable to common shareholders
Net income	93,695,000	35,451,000	162,085,000	139,664,000
Other comprehensive loss - foreign currency translation	(7,970,000)	(13,000,000)	(6,229,000)	(5,189,000)
Other comprehensive (loss) income - derivative instruments	(1,220,000)	666,000	(1,539,000)	(990,000)
Other comprehensive loss	(9,190,000)	(12,334,000)	(7,768,000)	(6,179,000)
Total comprehensive income	$ 84,505,000	$ 23,117,000	$ 154,317,000	$ 133,485,000
Weighted average number of common shares outstanding
Basic	152,121	150,976	152,134	150,541
Diluted	152,715	151,642	152,760	151,215
Net income allocated to general partners	$ 91,331,000	$ 34,423,000	$ 157,797,000	$ 135,572,000
Net income allocated to limited partners	2,306,000	944,000	4,117,000	3,618,000
Amounts attributable to common shareholders
Income from continuing operations	93,637,000	35,234,000	161,914,000	90,914,000
Net income available to common shareholders	$ 93,519,000	$ 35,249,000	$ 161,560,000	$ 138,836,000
Common shares [Member]
Basic:
Income from continuing operations	$ 0.61	$ 0.23	$ 1.06	$ 0.60
Income from discontinued operations	0	0	0	0.32
Income per common share - basic	0.61	0.23	1.06	0.92
Diluted:
Income from continuing operations	0.61	0.23	1.06	0.60
Income from discontinued operations	0	0	0	0.32
Income per common share - diluted	0.61	0.23	1.06	0.92
Distributions per common share or unit	0.475	0.475	1.425	1.425
Common Units [Member] | Liberty Property Limited Partnership [Member]
Basic:
Income from continuing operations	0.61	0.23	1.06	0.60
Income from discontinued operations	0	0	0	0.32
Income per common share - basic	0.61	0.23	1.06	0.92
Diluted:
Income from continuing operations	0.61	0.23	1.06	0.60
Income from discontinued operations	0	0	0	0.32
Income per common share - diluted	0.61	0.23	1.06	0.92
Distributions per common share or unit	$ 0.475	$ 0.475	$ 1.425	$ 1.425

Income Statement Parenthetical

Income Statement Parenthetical (Parentheticals) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Gain on property dispositions	$ 0	$ 38	$ 0	$ 46,292
Liberty Property Limited Partnership [Member]
Gain on property dispositions	$ 0	$ 38	$ 0	$ 46,292

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($)	Total	Common Shares Of Beneficial Interest [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Distributions in Excess of Net Income [Member]	Total Liberty Property Trust Shareholders' Equity [Member]	Noncontrolling interest operating partnership Common [Member]	Noncontrolling interest-consolidated joint ventures [Member]	Total Equity [Member]	Liberty Property Limited Partnership [Member]	Liberty Property Limited Partnership [Member]General Partners Equity [Member]	Liberty Property Limited Partnership [Member]Limited Partners' Equity - Common Units [Member]	Liberty Property Limited Partnership [Member]Noncontrolling interest-consolidated joint ventures [Member]	Liberty Property Limited Partnership [Member]Total Equity [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 139,664,000									$ 139,664,000
Other comprehensive loss - foreign currency translation	(5,189,000)									(5,189,000)
Other comprehensive loss - derivative instruments	(990,000)									(990,000)
Beginning Balance at Dec. 31, 2014	3,086,377,000	$ 149,000	$ 3,688,644,000	$ (6,252,000)	$ (654,869,000)	$ 3,027,672,000	$ 54,786,000	$ 3,919,000	$ 3,086,377,000	3,086,377,000	$ 3,027,672,000	$ 54,786,000	$ 3,919,000	$ 3,086,377,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares			38,195,000			38,195,000			38,195,000
Net income	162,085,000				157,797,000	157,797,000	3,763,000	171,000	161,731,000	162,085,000	157,797,000	3,763,000	171,000	161,731,000
Redemption of limited partners common units for common shares			224,000			224,000	(224,000)		0		224,000	(224,000)		0
Contributions from partners											49,595,000			49,595,000
Distributions					(212,019,000)	(212,019,000)	(5,173,000)	(171,000)	(217,363,000)
Distributions to partners											(212,019,000)	(5,173,000)	(171,000)	(217,363,000)
Share/Unit repurchase		(1,000)	(65,462,000)			(65,463,000)			(65,463,000)		(65,463,000)			(65,463,000)
Share-based compensation			11,400,000			11,400,000			11,400,000
Other comprehensive loss - foreign currency translation	(6,229,000)			(6,082,000)		(6,082,000)	(147,000)		(6,229,000)	(6,229,000)	(6,082,000)	(147,000)		(6,229,000)
Other comprehensive loss - derivative instruments	(1,539,000)			(1,503,000)		(1,503,000)	(36,000)		(1,539,000)	(1,539,000)	(1,503,000)	(36,000)		(1,539,000)
Ending Balance at Sep. 30, 2015	3,007,109,000	$ 148,000	$ 3,673,001,000	$ (13,837,000)	$ (709,091,000)	$ 2,950,221,000	$ 52,969,000	$ 3,919,000	$ 3,007,109,000	3,007,109,000	$ 2,950,221,000	$ 52,969,000	$ 3,919,000	$ 3,007,109,000
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2014	7,537,000									7,537,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (Mezzanine)	354,000									354,000
Distributions (Mezzanine)	(354,000)									(354,000)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Sep. 30, 2015	$ 7,537,000									$ 7,537,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
OPERATING ACTIVITIES
Net income	$ 162,085,000	$ 139,664,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	173,726,000	176,207,000
Amortization of deferred financing costs	3,249,000	3,727,000
Impairment - real estate assets	16,775,000	0
Equity in earnings of unconsolidated joint ventures	(805,000)	(7,297,000)
Distributions from unconsolidated joint ventures	2,490,000	0
Gain on property dispositions	(56,987,000)	(48,170,000)
Share-based compensation/Non-cash compensation	10,709,000	10,422,000
Other	(8,143,000)	(5,202,000)
Changes in operating assets and liabilities:
Restricted cash	4,914,000	28,469,000
Accounts receivable	1,023,000	(4,771,000)
Deferred rent receivable	(17,122,000)	(11,928,000)
Prepaid expenses and other assets	(20,182,000)	(38,882,000)
Accounts payable	8,312,000	18,824,000
Accrued interest	19,258,000	15,500,000
Other liabilities	371,000	(26,232,000)
Net cash provided by operating activities	299,673,000	250,331,000
INVESTING ACTIVITIES
Investment in operating properties - acquisitions	(100,756,000)	(97,677,000)
Investment in operating properties - other	(58,038,000)	(61,480,000)
Investments in and advances to unconsolidated joint ventures	(30,609,000)	(13,894,000)
Distributions from unconsolidated joint ventures	23,093,000	10,213,000
Net proceeds from disposition of properties/land	243,943,000	351,301,000
Investment in development in progress	(123,547,000)	(222,484,000)
Investment in land held for development	(101,934,000)	(73,547,000)
Investment in deferred leasing costs	(34,404,000)	(28,409,000)
Other	(6,366,000)	5,501,000
Net cash used in investing activities	(188,618,000)	(130,476,000)
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	38,195,000	44,097,000
Payments for Repurchase of Common Stock	(65,463,000)	0
Proceeds from unsecured notes	398,576,000	0
Repayment of unsecured notes	(300,000,000)	(200,000,000)
Repayments of mortgage loans	(112,970,000)	(9,329,000)
Proceeds from credit facility	919,700,000	179,750,000
Repayments on credit facility	(786,700,000)	(38,800,000)
Payment of deferred financing costs	(3,478,000)	(3,622,000)
Distribution paid on common shares	(212,402,000)	(209,779,000)
Distribution paid on units	(5,704,000)	(5,692,000)
Net cash used in financing activities	(130,246,000)	(243,375,000)
Net decrease in cash and cash equivalents	(19,191,000)	(123,520,000)
Decrease in cash and cash equivalents related to foreign currency translation	(1,503,000)	(808,000)
Cash and cash equivalents at beginning of period	69,346,000	163,414,000
Cash and cash equivalents at end of period	48,652,000	39,086,000
Liberty Property Limited Partnership [Member]
OPERATING ACTIVITIES
Net income	162,085,000	139,664,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	173,726,000	176,207,000
Amortization of deferred financing costs	3,249,000	3,727,000
Impairment - real estate assets	16,775,000	0
Equity in earnings of unconsolidated joint ventures	(805,000)	(7,297,000)
Distributions from unconsolidated joint ventures	2,490,000	0
Gain on property dispositions	(56,987,000)	(48,170,000)
Share-based compensation/Non-cash compensation	10,709,000	10,422,000
Other	(8,143,000)	(5,202,000)
Changes in operating assets and liabilities:
Restricted cash	4,914,000	28,469,000
Accounts receivable	1,023,000	(4,771,000)
Deferred rent receivable	(17,122,000)	(11,928,000)
Prepaid expenses and other assets	(20,182,000)	(38,882,000)
Accounts payable	8,312,000	18,824,000
Accrued interest	19,258,000	15,500,000
Other liabilities	371,000	(26,232,000)
Net cash provided by operating activities	299,673,000	250,331,000
INVESTING ACTIVITIES
Investment in operating properties - acquisitions	(100,756,000)	(97,677,000)
Investment in operating properties - other	(58,038,000)	(61,480,000)
Investments in and advances to unconsolidated joint ventures	(30,609,000)	(13,894,000)
Distributions from unconsolidated joint ventures	23,093,000	10,213,000
Net proceeds from disposition of properties/land	243,943,000	351,301,000
Investment in development in progress	(123,547,000)	(222,484,000)
Investment in land held for development	(101,934,000)	(73,547,000)
Investment in deferred leasing costs	(34,404,000)	(28,409,000)
Other	(6,366,000)	5,501,000
Net cash used in investing activities	(188,618,000)	(130,476,000)
FINANCING ACTIVITIES
Payments for Repurchase of Common Stock	(65,463,000)	0
Proceeds from unsecured notes	398,576,000	0
Repayment of unsecured notes	(300,000,000)	(200,000,000)
Repayments of mortgage loans	(112,970,000)	(9,329,000)
Proceeds from credit facility	919,700,000	179,750,000
Repayments on credit facility	(786,700,000)	(38,800,000)
Payment of deferred financing costs	(3,478,000)	(3,622,000)
Capital contributions	38,195,000	44,097,000
Distributions to partners	(218,106,000)	(215,471,000)
Net cash used in financing activities	(130,246,000)	(243,375,000)
Net decrease in cash and cash equivalents	(19,191,000)	(123,520,000)
Decrease in cash and cash equivalents related to foreign currency translation	(1,503,000)	(808,000)
Cash and cash equivalents at beginning of period	69,346,000	163,414,000
Cash and cash equivalents at end of period	$ 48,652,000	$ 39,086,000

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Organization and Basis of Presentation Organization Liberty Property Trust (the “Trust”) is a self-administered and self-managed Maryland real estate investment trust (a “REIT”). Substantially all of the Trust’s assets are owned directly or indirectly, and substantially all of the Trust’s operations are conducted directly or indirectly, by its subsidiary, Liberty Property Limited Partnership, a Pennsylvania limited partnership (the “Operating Partnership” and, together with the Trust and their consolidated subsidiaries, the “Company”). The Trust is the sole general partner and also a limited partner of the Operating Partnership, owning 97.7% of the common equity of the Operating Partnership at September 30, 2015 . The Company owns and operates industrial properties nationally and owns and operates office properties in a focused group of office markets. Additionally, the Company owns certain assets in the United Kingdom. Unless otherwise indicated, the notes to the Consolidated Financial Statements apply to both the Trust and the Operating Partnership. The terms the “Company,” “we,” “our” and “us” mean the Trust and Operating Partnership collectively. Basis of Presentation The accompanying unaudited consolidated financial statements of the Company have been prepared in accordance with United States generally accepted accounting principles (“US GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements and should be read in conjunction with the consolidated financial statements and notes thereto included in the Annual Report on Form 10-K of the Company for the year ended December 31, 2014 . In the opinion of management, all adjustments (consisting solely of normal recurring adjustments) necessary for a fair presentation of the financial statements for these interim periods have been included. The results of interim periods are not necessarily indicative of the results to be obtained for a full fiscal year. As disclosed in Note 2, Income per Common Share of the Trust - Share Repurchase, the Company repurchased common shares pursuant to a share repurchase program authorized by the Company's Board of Trustees. These repurchased shares along with those repurchased in prior periods are subject to state corporate laws that establish the legal status of redeemed shares and prevent them from being reported as treasury shares within the consolidated financial statements. The Trust previously misclassified the repurchased shares as common shares in treasury. The share repurchases should have been classified as reductions of common shares of beneficial interest and additional paid-in capital. The accompanying consolidated balance sheet of the Trust as of December 31, 2014 has been restated to correct the misclassification. The correction results in reductions in common shares of beneficial interest and additional paid-in capital at December 31, 2014 of $1,000 and $51.9 million , respectively, from the previously reported amounts of $150,000 and $3,740.6 million , respectively. The reclassification has no impact on the previously reported consolidated statements of comprehensive income, nor does it have any effect on the previously reported consolidated statements of cash flows. In addition, the reclassification has no impact on the previously reported consolidated financial statements of the Operating Partnership. Recently Issued Accounting Standards In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"), which supersedes nearly all existing revenue recognition guidance. The standard clarifies the required factors that an entity must consider when recognizing revenue. The standard also requires additional disclosures concerning contracts with customers, judgments concerning revenue recognition, and assets recognized for the costs to obtain or fulfill a contract. ASU 2014-09 is effective for the Company beginning January 1, 2018. The Company is evaluating the impact ASU 2014-09 will have on its financial position and results of operations. In April 2015, the FASB issued ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs ("ASU 2015-03") . The standard requires the costs for issuing debt to appear on a balance sheet as a direct deduction from the debt's value. ASU 2015-03 is effective for the Company beginning January 1, 2016. The standard would be applied retrospectively. The Company does not anticipate that the adoption of ASU 2015-03 will have a material impact on its financial position or results of operations. In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis (Topic 810) ("ASU 2015-02"). The standard requires that all entities re-evaluate and revise consolidation documentation for limited partnerships and similar legal entities. It makes changes to both the variable interest model and voting model. ASU 2015-02 is effective for the Company beginning January 1, 2016. The standard allows for either a full retrospective or a modified retrospective approach to adoption. The Company is evaluating the impact ASU 2015-02 will have on its financial position and results of operations.

Income per Common Share of the

Income per Common Share of the Trust	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Income per Common Share of the Trust The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): For the Three Months Ended For the Three Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 91,331 148,582 $ 0.61 $ 34,293 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Income from continuing operations net of noncontrolling interest - diluted $ 91,331 149,176 $ 0.61 $ 34,293 148,088 $ 0.23 Discontinued operations net of noncontrolling interest - basic $ — 148,582 $ — $ 130 147,422 $ — Dilutive shares for long-term compensation plans — 594 — 666 Discontinued operations net of noncontrolling interest - diluted $ — 149,176 $ — $ 130 148,088 $ — Net income available to common shareholders - basic $ 91,331 148,582 $ 0.61 $ 34,423 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Net income available to common shareholders - diluted $ 91,331 149,176 $ 0.61 $ 34,423 148,088 $ 0.23 For the Nine Months Ended For the Nine Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 157,797 148,594 $ 1.06 $ 88,430 146,987 $ 0.60 Dilutive shares for long-term compensation plans — 626 — 674 Income from continuing operations net of noncontrolling interest - diluted 157,797 149,220 $ 1.06 88,430 147,661 $ 0.60 Discontinued operations net of noncontrolling interest - basic — 148,594 $ — 47,142 146,987 $ 0.32 Dilutive shares for long-term compensation plans — 626 — 674 Discontinued operations net of noncontrolling interest - diluted — 149,220 $ — 47,142 147,661 $ 0.32 Net income available to common shareholders - basic 157,797 148,594 $ 1.06 135,572 146,987 $ 0.92 Dilutive shares for long-term compensation plans — 626 — 674 Net income available to common shareholders - diluted $ 157,797 149,220 $ 1.06 $ 135,572 147,661 $ 0.92 Dilutive shares for long-term compensation plans represent the unvested common shares outstanding during the periods as well as the dilutive effect of outstanding options. The amount of anti-dilutive options excluded from the computation of diluted income per common share for the three and nine months ended September 30, 2015 was 2,260,000 and 1,528,000 , respectively, as compared to 1,183,000 and 850,000 , respectively, for the same periods in 2014 . During the three and nine months ended September 30, 2015 , 12,000 and 65,000 common shares, respectively, were issued upon the exercise of options. During the year ended December 31, 2014 , 44,000 common shares were issued upon the exercise of options. Share Repurchase In August 2015, the Company’s Board of Trustees authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common shares. Purchases made pursuant to the program will be made in either the open market or in privately negotiated transactions from time to time as permitted by securities laws and other legal requirements. During the three and nine months ended September 30, 2015, the Company purchased an aggregate of 2,125,000 common shares for $65.5 million as part of the share repurchase plan.

Income per Common Unit of the O

Income per Common Unit of the Operating Partnership	9 Months Ended
	Sep. 30, 2015
Earnings Per Unit, Basic and Diluted [Line Items]
Earnings Per Share [Text Block]	Income per Common Share of the Trust The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): For the Three Months Ended For the Three Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 91,331 148,582 $ 0.61 $ 34,293 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Income from continuing operations net of noncontrolling interest - diluted $ 91,331 149,176 $ 0.61 $ 34,293 148,088 $ 0.23 Discontinued operations net of noncontrolling interest - basic $ — 148,582 $ — $ 130 147,422 $ — Dilutive shares for long-term compensation plans — 594 — 666 Discontinued operations net of noncontrolling interest - diluted $ — 149,176 $ — $ 130 148,088 $ — Net income available to common shareholders - basic $ 91,331 148,582 $ 0.61 $ 34,423 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Net income available to common shareholders - diluted $ 91,331 149,176 $ 0.61 $ 34,423 148,088 $ 0.23 For the Nine Months Ended For the Nine Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 157,797 148,594 $ 1.06 $ 88,430 146,987 $ 0.60 Dilutive shares for long-term compensation plans — 626 — 674 Income from continuing operations net of noncontrolling interest - diluted 157,797 149,220 $ 1.06 88,430 147,661 $ 0.60 Discontinued operations net of noncontrolling interest - basic — 148,594 $ — 47,142 146,987 $ 0.32 Dilutive shares for long-term compensation plans — 626 — 674 Discontinued operations net of noncontrolling interest - diluted — 149,220 $ — 47,142 147,661 $ 0.32 Net income available to common shareholders - basic 157,797 148,594 $ 1.06 135,572 146,987 $ 0.92 Dilutive shares for long-term compensation plans — 626 — 674 Net income available to common shareholders - diluted $ 157,797 149,220 $ 1.06 $ 135,572 147,661 $ 0.92 Dilutive shares for long-term compensation plans represent the unvested common shares outstanding during the periods as well as the dilutive effect of outstanding options. The amount of anti-dilutive options excluded from the computation of diluted income per common share for the three and nine months ended September 30, 2015 was 2,260,000 and 1,528,000 , respectively, as compared to 1,183,000 and 850,000 , respectively, for the same periods in 2014 . During the three and nine months ended September 30, 2015 , 12,000 and 65,000 common shares, respectively, were issued upon the exercise of options. During the year ended December 31, 2014 , 44,000 common shares were issued upon the exercise of options. Share Repurchase In August 2015, the Company’s Board of Trustees authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common shares. Purchases made pursuant to the program will be made in either the open market or in privately negotiated transactions from time to time as permitted by securities laws and other legal requirements. During the three and nine months ended September 30, 2015, the Company purchased an aggregate of 2,125,000 common shares for $65.5 million as part of the share repurchase plan.
Liberty Property Limited Partnership [Member]
Earnings Per Unit, Basic and Diluted [Line Items]
Earnings Per Share [Text Block]	Income per Common Unit of the Operating Partnership The following table sets forth the computation of basic and diluted income per common unit of the Operating Partnership (in thousands, except per unit amounts): For the Three Months Ended For the Three Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations - net of noncontrolling interest - consolidated joint ventures $ 93,637 $ 35,234 Less: Preferred unit distributions (118 ) (118 ) Income from continuing operations available to common unitholders - basic $ 93,519 152,121 $ 0.61 $ 35,116 150,976 $ 0.23 Dilutive units for long-term compensation plans — 594 — 666 Income from continuing operations available to common unitholders - diluted $ 93,519 152,715 $ 0.61 $ 35,116 151,642 $ 0.23 Income from discontinued operations - basic $ — 152,121 $ — $ 133 150,976 $ — Dilutive units for long-term compensation plans — 594 — 666 Income from discontinued operations - diluted $ — 152,715 $ — $ 133 151,642 $ — Income available to common unitholders - basic $ 93,519 152,121 $ 0.61 $ 35,249 150,976 $ 0.23 Dilutive units for long-term compensation plans — 594 — 666 Income available to common unitholders - diluted $ 93,519 152,715 $ 0.61 $ 35,249 151,642 $ 0.23 For the Nine Months Ended For the Nine Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations net of noncontrolling interest - consolidated joint ventures $ 161,914 $ 90,914 Less: Preferred unit distributions (354 ) (354 ) Income from continuing operations available to common unitholders - basic 161,560 152,134 $ 1.06 90,560 150,541 $ 0.60 Dilutive units for long-term compensation plans — 626 — 674 Income from continuing operations available to common unitholders - diluted 161,560 152,760 $ 1.06 90,560 151,215 $ 0.60 Income from discontinued operations - basic — 152,134 $ — 48,276 150,541 $ 0.32 Dilutive units for long-term compensation plans — 626 — 674 Income from discontinued operations - diluted — 152,760 $ — 48,276 151,215 $ 0.32 Income available to common unitholders - basic 161,560 152,134 $ 1.06 138,836 150,541 $ 0.92 Dilutive units for long-term compensation plans — 626 — 674 Income available to common unitholders - diluted $ 161,560 152,760 $ 1.06 $ 138,836 151,215 $ 0.92 Dilutive units for long-term compensation plans represent the unvested common units outstanding during the periods as well as the dilutive effect of outstanding options. The amount of anti-dilutive options excluded from the computation of diluted income per common unit for the three and nine months ended September 30, 2015 was 2,260,000 and 1,528,000 , respectively, as compared to 1,183,000 and 850,000 , respectively, for the same periods in 2014 . During the three and nine months ended September 30, 2015 , 12,000 and 65,000 common units, respectively, were issued upon exercise of options. During the year ended December 31, 2014 , 44,000 common units were issued upon the exercise of options. Share Repurchase In August 2015, the Company’s Board of Trustees authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common units. Purchases made pursuant to the program will be made in either the open market or in privately negotiated transactions from time to time as permitted by securities laws and other legal requirements. During the three and nine months ended September 30, 2015, the Company purchased an aggregate of 2,125,000 common shares for $65.5 million as part of the share repurchase plan. In connection with these repurchases, an equal number of common units were repurchased by the Operating Partnership from the Trust.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Income (Loss) The following table sets forth the components of Accumulated Other Comprehensive Income (Loss) (in thousands): Nine Months Ended September 30, 2015 2014 Foreign Currency Translation: Beginning balance $ (5,823 ) $ 8,592 Translation adjustment (6,229 ) (5,189 ) Ending balance (12,052 ) 3,403 Derivative Instruments: Beginning balance (377 ) 1,584 Unrealized loss (2,592 ) (2,090 ) Reclassification adjustment (1) 1,053 1,100 Ending balance (1,916 ) 594 Total accumulated other comprehensive (loss) income (13,968 ) 3,997 Less: portion included in noncontrolling interest – operating partnership 131 (290 ) Total accumulated other comprehensive (loss) income included in shareholders' equity/owners' equity $ (13,837 ) $ 3,707 (1) Amounts reclassified out of Accumulated Other Comprehensive (Loss) Income/General & Limited Partner's Equity into contractual interest expense.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting, Measurement Disclosures [Abstract]
Segment Information	Segment Information The Company owns and operates industrial properties nationally and owns and operates office properties in a focused group of office markets. Additionally, the Company owns certain assets in the United Kingdom. The Company's reportable segments are as follows. • Carolinas; • Chicago/Milwaukee; • Houston; • Lehigh/Central PA; • Minnesota; • Orlando; • Philadelphia; • Richmond/Hampton Roads; • Southeastern PA; • South Florida; • Tampa; and • United Kingdom. Certain other segments are aggregated into an "Other" category which includes the reportable segments: Arizona; Atlanta; Cincinnati/Columbus/Indianapolis; Dallas; Maryland; New Jersey; Northern Virginia; Southern California; Washington D.C. and other. The Company evaluates the performance of its reportable segments based on net operating income. Net operating income includes operating revenue from external customers, real estate taxes, amortization of lease transaction costs and other operating expenses which relate directly to the management and operation of the assets within each reportable segment. The Company's accounting policies for the segments are the same as those used in the Company's consolidated financial statements. There are no material inter-segment transactions. The operating information by reportable segment is as follows (in thousands): For the Three Months For the Nine Months Ended September 30, Ended September 30, 2015 2014 2015 2014 Operating revenue Carolinas $ 10,555 $ 9,479 $ 30,462 $ 26,282 Chicago/Milwaukee 8,872 8,004 27,596 24,727 Houston 12,981 12,833 38,455 36,828 Lehigh/Central PA 33,746 30,034 100,144 87,853 Minnesota 11,751 13,925 36,699 41,217 Orlando 5,547 8,463 16,221 24,519 Philadelphia 10,552 8,303 30,422 26,402 Richmond/Hampton Roads 5,168 10,358 25,809 30,542 South Florida 12,957 12,012 37,542 36,028 Southeastern PA 36,718 36,087 114,430 110,833 Tampa 13,568 13,597 40,667 40,001 United Kingdom 3,776 4,111 11,466 12,430 Other 32,801 31,144 99,636 96,300 Segment-level operating revenue 198,992 198,350 609,549 593,962 Reconciliation to total operating revenues Discontinued operations — (9 ) — (4,728 ) Other (20 ) 15 (157 ) (288 ) Total operating revenue $ 198,972 $ 198,356 $ 609,392 $ 588,946 Net operating income Carolinas $ 7,795 $ 6,570 $ 21,479 $ 18,006 Chicago/Milwaukee 5,792 5,382 18,660 15,518 Houston 7,829 7,510 22,739 21,794 Lehigh/Central PA 24,289 21,634 70,907 60,647 Minnesota 4,461 6,575 15,595 19,964 Orlando 3,835 5,411 11,091 16,257 Philadelphia 7,898 6,736 22,230 20,247 Richmond/Hampton Roads 3,014 6,144 15,538 18,118 South Florida 7,012 6,647 20,990 21,066 Southeastern PA 20,887 20,516 63,301 60,175 Tampa 8,454 8,213 25,780 25,142 United Kingdom 2,619 2,468 7,917 8,040 Other 21,750 20,715 66,138 61,614 Segment-level net operating income 125,635 124,521 382,365 366,588 Reconciliation to income from continuing operations Interest expense (1) (33,559 ) (37,958 ) (103,295 ) (116,192 ) Depreciation/amortization expense (1) (2) (40,870 ) (44,538 ) (126,162 ) (133,636 ) Impairment - real estate assets — — (16,775 ) — Gain (loss) on property dispositions 53,467 (20 ) 56,987 1,878 Equity in (loss) earnings of unconsolidated joint ventures (847 ) 1,592 805 7,297 General and administrative expense (1) (2) (9,456 ) (8,556 ) (33,043 ) (29,189 ) Discontinued operations excluding interest and gain on property dispositions — (95 ) — (2,541 ) Income taxes (2) (526 ) (821 ) (2,283 ) (1,966 ) Other (149 ) 1,193 3,486 (851 ) Income from continuing operations $ 93,695 $ 35,318 $ 162,085 $ 91,388 (1) Includes activity on discontinued operations. (2) Excludes costs which are included in determining segment-level net operating income. During the three months ended September 30, 2015 , the Company acquired a portfolio of three operating properties and 139 acres of developable land for a total purchase price of $86.6 million . These properties, comprising 921,000 square feet of leaseable space, are located in the Company's Houston reportable segment. During the nine months ended September 30, 2015 , the Company acquired four operating properties comprising 1.3 million square feet for a total purchase price of $123.4 million in the Company's Southern California and Houston reportable segments. This purchase price also includes 139 acres of developable land. The Company's sales by reportable segment for the three and nine months ended September 30, 2015 are as follows: Three months ended September 30, 2015 Nine months ended September 30, 2015 Properties Sold Square Feet (000s) Gross Proceeds (000s) Properties Sold Square Feet (000s) Gross Proceeds (000s) Minnesota 1 135 $ 19,900 2 223 $ 25,700 Richmond/Hampton Roads — — — 22 1,319 110,300 (1) Southeastern PA 3 250 63,500 4 333 72,220 Tampa 1 32 2,525 1 32 2,525 Other 1 31 3,859 7 569 37,371 Total 6 448 $ 89,784 36 2,476 $ 248,116 (1) Includes proceeds from the sale of 3.1 acres of land. During the nine months ended September 30, 2015 , the Company sold 22 properties and 3.1 acres of land in the Richmond/Hampton Roads segment for $110.3 million to a firm controlled by the brother of David L. Lingerfelt, a member of the Company's Board of Trustees. The Company's total assets by reportable segment as of September 30, 2015 and December 31, 2014 is as follows (in thousands): September 30, 2015 December 31, 2014 Total assets Carolinas $ 336,634 $ 325,690 Chicago/Milwaukee 426,729 422,531 Houston 520,128 418,154 Lehigh/Central PA 1,094,009 1,023,641 Minnesota 321,194 333,506 Orlando 160,020 160,899 Philadelphia 416,373 366,577 Richmond/Hampton Roads 126,909 250,205 South Florida 419,008 400,034 Southeastern PA 658,063 698,163 Tampa 329,687 335,652 United Kingdom 219,362 231,276 Other 1,577,732 1,553,250 Segment-level total assets 6,605,848 6,519,578 Corporate Other 83,945 105,958 Total assets $ 6,689,793 $ 6,625,536

Accounting for the Impairment o

Accounting for the Impairment or Disposal of Long-Lived Assets	9 Months Ended
	Sep. 30, 2015
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	Accounting for the Impairment or Disposal of Long-Lived Assets Prior to the adoption of Accounting Standards Update (ASU) 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360), Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity ("ASU 2014-08") on January 1, 2014, the results of operations for all operating properties sold or held for sale during the reported periods were shown under discontinued operations on the consolidated statements of comprehensive income. Under ASU 2014-08, operating properties that were sold or classified as held for sale before the adoption of ASU 2014-08 continue to be classified as discontinued operations. Accordingly, operating properties previously reported as discontinued operations will continue to be presented as discontinued operations on the consolidated statements of comprehensive income for all periods presented. A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenues $ — $ 9 $ — $ 4,728 Operating expenses — 86 — (2,226 ) Interest and other income — — — 39 Interest expense — — — (557 ) Depreciation and amortization — — — — Income before gain on property dispositions — 95 — 1,984 Gain on property dispositions — 38 — 46,292 Net income $ — $ 133 $ — $ 48,276 Interest expense has been allocated to discontinued operations. The allocation of interest expense to discontinued operations was based on the ratio of net assets sold and held for sale (without continuing involvement) to the sum of total net assets plus consolidated debt.
Asset Impairment Charges [Text Block]	Asset Impairment The Company disposes of and anticipates the potential disposition of certain properties prior to the end of their remaining useful lives. There were no impairments recognized during the three months ended September 30, 2015. During the nine months ended September 30, 2015 , the Company recognized $16.8 million in impairments, $13.4 million of which related to properties sold in the Company's Richmond/Hampton Roads reportable segment (see Note 5), $2.3 million of which related to the Company's Southeastern Pennsylvania reportable segment and $1.0 million of which related to the Company's Maryland reportable segment. The Company determined these impairments based on third party offer prices and quoted offer prices for comparable transactions which are Level 2 and Level 3 inputs, respectively, according to the fair value hierarchy established by the FASB in Topic 820, "Fair Value Measurements and Disclosures." The Company has evaluated each of its properties and land held for development and has determined that there were no additional valuation adjustments necessary at September 30, 2015 . There were no impairments recognized during the three or nine months ended September 30, 2014 .

Noncontrolling Interests of the

Noncontrolling Interests of the Trust	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Attributable to Noncontrolling Interest [Abstract]
Noncontrolling Interests	Noncontrolling Interests of the Trust Noncontrolling interests in the accompanying financial statements represent the interests of the common and preferred units in the Operating Partnership not held by the Trust. In addition, noncontrolling interests include third-party ownership interests in consolidated joint venture investments. Common units The common units outstanding have the same economic characteristics as common shares of the Trust. The 3,539,075 outstanding common units as of September 30, 2015 not held by the Trust share proportionately in the net income or loss and in any distributions of the Operating Partnership. The common units of the Operating Partnership not held by the Trust are redeemable at any time at the option of the holder. The Trust, as the sole general partner of the Operating Partnership, may at its option elect to settle the redemption in cash or through the exchange on a one-for-one basis of unregistered common shares of the Trust. The market value of the 3,539,075 outstanding common units based on the closing price of the common shares of the Trust at September 30, 2015 was $ 111.5 million .

Limited Partners' Equity of the

Limited Partners' Equity of the Operating Partnership	9 Months Ended
	Sep. 30, 2015
Preferred Units [Line Items]
Noncontrolling Interest Disclosure [Text Block]	Noncontrolling Interests of the Trust Noncontrolling interests in the accompanying financial statements represent the interests of the common and preferred units in the Operating Partnership not held by the Trust. In addition, noncontrolling interests include third-party ownership interests in consolidated joint venture investments. Common units The common units outstanding have the same economic characteristics as common shares of the Trust. The 3,539,075 outstanding common units as of September 30, 2015 not held by the Trust share proportionately in the net income or loss and in any distributions of the Operating Partnership. The common units of the Operating Partnership not held by the Trust are redeemable at any time at the option of the holder. The Trust, as the sole general partner of the Operating Partnership, may at its option elect to settle the redemption in cash or through the exchange on a one-for-one basis of unregistered common shares of the Trust. The market value of the 3,539,075 outstanding common units based on the closing price of the common shares of the Trust at September 30, 2015 was $ 111.5 million .
Liberty Property Limited Partnership [Member]
Preferred Units [Line Items]
Noncontrolling Interest Disclosure [Text Block]	Limited Partners' Equity and Noncontrolling Interest of the Operating Partnership Limited partners' equity in the accompanying financial statements represents the interests of the common and preferred units in the Operating Partnership not held by the Trust. The Operating Partnership's noncontrolling interest includes third-party ownership interests in consolidated joint venture investments. Common units The common units outstanding have the same economic characteristics as common shares of the Trust. The 3,539,075 outstanding common units as of September 30, 2015 not held by the Trust are the limited partners' equity - common units held by persons and entities other than the Trust. The common units of the Operating Partnership not held by the Trust are redeemable at any time at the option of the holder. The Trust, as the sole general partner of the Operating Partnership, may at its option elect to settle the redemption in cash or through the exchange on a one-for-one basis of unregistered common shares of the Trust. The market value of the 3,539,075 outstanding common units at September 30, 2015 based on the closing price of the common shares of the Trust at September 30, 2015 was $ 111.5 million .

Noncontrolling Interest - Opera

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units	9 Months Ended
	Sep. 30, 2015
Temporary Equity [Line Items]
Stockholders' Equity Note Disclosure [Text Block]	Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units As of September 30, 2015 , the Company had outstanding the following cumulative preferred units of the Operating Partnership: ISSUE AMOUNT UNITS LIQUIDATION PREFERENCE DIVIDEND RATE (in 000’s) Series I-2 $ 7,537 301 $25 6.25 % The preferred units are putable at the holder's option at any time and are callable at the Operating Partnership's option after a stated period of time for cash.

Indebtedness

Indebtedness	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Indebtedness In March 2015, the Company used proceeds from its unsecured credit facility together with available cash on hand to repay all $300 million of its 5.125% senior unsecured notes due March 2015. In March 2015, the Company issued $400 million of 3.75% senior unsecured notes due 2025. The net proceeds from this issuance were used to repay borrowings under the Company's unsecured credit facility and for general corporate purposes. In August 2015, the Company used proceeds from its unsecured credit facility to prepay without penalty a $105.8 million 7.0% mortgage loan due February 2016.

Disclosure of Fair Value of Fin

Disclosure of Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2015
Debt Instrument, Fair Value Disclosure [Abstract]
Disclosure of Fair Value of Financial Instruments	Disclosure of Fair Value of Financial Instruments The following disclosure of estimated fair value was determined by management using available market information and appropriate valuation methodologies. However, considerable judgment is necessary to interpret market data and develop estimated fair value. Accordingly, the following estimates are not necessarily indicative of the amounts the Company could have realized on disposition of the financial instruments at September 30, 2015 and December 31, 2014 . The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. The carrying value of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued interest, dividend and distributions payable and other liabilities are reasonable estimates of fair value because of the short-term nature of these instruments. The carrying value of the outstanding amounts under the Company's credit facility is a reasonable estimate of fair value because interest rates float at a rate based on LIBOR. The Company determines the fair value of its interest rate swaps by using the standard methodology of netting discounted future fixed cash payments with the discounted expected variable cash receipts. These variable cash receipts of interest rate swaps are based on expectations of future LIBOR interest rates (forward curves) estimated by observing market LIBOR interest rate curves. This is a Level 2 fair value calculation. Also, credit valuation adjustments are factored into the fair value calculations to account for potential nonperformance risk. These credit valuation adjustments were concluded to be not significant inputs for the fair value calculations for the periods presented. See Note 13 - Derivative Instruments. The Company used a discounted cash flow model to determine the estimated fair value of its debt as of September 30, 2015 . This is a Level 3 fair value calculation. The inputs used in preparing the discounted cash flow model include actual maturity dates and scheduled cash flows as well as estimates for market value discount rates. The Company updates the discounted cash flow model on a quarterly basis to reflect any changes in the Company's debt holdings and changes to discount rate assumptions. The following summarizes the fair value of the Company's mortgage loans and unsecured notes as of December 31, 2014 and September 30, 2015 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2014 $ 487,301 $ 501,231 $ 2,509,094 $ 2,704,069 As of September 30, 2015 $ 372,660 $ 381,500 $ 2,608,307 $ 2,621,855

Unconsolidated Joint Ventures

Unconsolidated Joint Ventures	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Unconsolidated Joint Ventures Liberty Washington, LP During the three and nine months ended September 30, 2015, Liberty Washington LP (a joint venture in which the Company holds a 25% interest) recognized impairment charges, the Company's share of which was $3.9 million and $11.5 million , respectively. The impairment charges were related to the Company's Northern Virginia reportable segment and the Company's share was included in equity in (loss) earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. The Company determined these impairments based on third party offer prices. This is a Level 2 fair value calculation. As of September 30, 2015, the joint venture was in default of a $46.4 million non-recourse mortgage loan related to certain properties within the joint venture in the Company's Northern Virginia reportable segment. Comcast Innovation and Technology Center The Company has entered into two joint ventures for the purpose of developing and owning the Comcast Innovation & Technology Center (the "Project") located on the 1800 block of Arch Street in Philadelphia, Pennsylvania. The 59 -story building will include 1.3 million square feet of rentable office space and a 222 -room Four Seasons Hotel. Completion of the first phase of the Project is anticipated to be in the third quarter of 2017. Project costs for the development of the Project, exclusive of tenant-funded interior improvements, are anticipated to be approximately $932 million . The Company's investment in the Project is expected to be approximately $185 million with 20% ownership interests in both joint ventures. The two joint ventures have engaged the Company as the developer of the Project pursuant to a Development Agreement by which the Company agrees, in consideration for a development fee, to be responsible for all aspects of the development of the Project and to guarantee the timely lien-free completion of construction of the Project and the payment, subject to certain exceptions, of any cost overruns incurred in the development of the Project. Liberty Venture I, LP During the nine months ended September 30, 2015 , Liberty Venture I, LP (a joint venture in which the Company holds a 25% interest) realized gross proceeds of $8.5 million from the sale of one property totaling 198,000 square feet in the Company's New Jersey reportable segment.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest rate swaps [Text Block]	Derivative Instruments The Company borrows funds at a combination of fixed and variable rates. Borrowings under the Company's revolving credit facility and certain bank mortgage loans bear interest at variable rates. Our long-term debt typically bears interest at fixed rates. Our interest rate risk management objectives are to limit generally the impact of interest rate changes on earnings and cash flows and to lower our overall borrowing costs. To achieve these objectives, from time to time, we enter into interest rate hedge contracts such as collars, swaps, caps and treasury lock agreements in order to mitigate our interest rate risk with respect to various debt instruments. We generally do not hold or issue these derivative contracts for trading or speculative purposes. The interest rate on all of our variable rate debt is generally adjusted at one or three month intervals, subject to settlements under interest rate hedge contracts. Interest rate swaps involve the receipt of variable-rate amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive (loss) income (for the Trust) and general partner's equity and limited partners' equity - common units (for the Operating Partnership) and is subsequently reclassified into interest expense in the period that the hedged forecasted transaction affects earnings. The Company determines the fair value of its interest rate swaps by using the standard methodology of netting discounted future fixed cash payments with the discounted expected variable cash receipts. These variable cash receipts of interest rate swaps are based on expectations of future LIBOR interest rates (forward curves) estimated by observing market LIBOR interest rate curves. This is a Level 2 fair value calculation. Also, credit valuation adjustments are factored into the fair value calculations to account for potential nonperformance risk. These credit valuation adjustments were concluded to be not significant inputs for the fair value calculations for the periods presented. The Company holds an interest in three interest rate swap contracts (“Swaps”) that eliminate the impact of changes in interest rates on the payments required under variable rate mortgages. The Swaps had aggregate notional amounts of $102.0 million and $103.6 million at September 30, 2015 and December 31, 2014 , respectively, and expire at various dates between 2018 and 2020 . The Company accounts for the effective portion of changes in the fair value of a derivative in accumulated other comprehensive loss and subsequently reclassifies the effective portion to earnings over the term that the hedged transaction affects earnings. The Company accounts for the ineffective portion of changes in the fair value of a derivative directly in earnings. The following table presents the location in the financial statements of the gains or losses recognized related to the Company’s cash flow hedges for the three and nine months ended September 30, 2015 and 2014: Three Months Ended Nine Months Ended September 30, 2015 September 30, 2014 September 30, 2015 September 30, 2014 (in thousands) Amount of (loss) gain related to the effective portion recognized in other comprehensive (loss) income $ (1,570 ) $ 299 $ (2,592 ) $ (2,083 ) Amount of (loss) gain related to the effective portion subsequently reclassified to earnings $ (350 ) $ (367 ) $ (1,053 ) $ (1,093 ) Amount of (loss) gain related to the ineffective portion $ (51 ) $ 13 $ (113 ) $ (42 ) The fair value of the Swaps in the amounts of $8.7 million and $8.5 million as of September 30, 2015 and December 31, 2014 , respectively, is included in other liabilities in the accompanying consolidated balance sheets. The Company estimates that $1.2 million will be reclassified from accumulated other comprehensive loss as an increase to interest expense over the next 12 months. The Company has agreements with its derivative counterparties that contain a provision whereby if the Company defaults on any of its indebtedness, including defaults where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. If the Company were to breach any of the contractual provisions of the derivative contracts, it would be required to settle its obligations under the agreements at their termination value including accrued interest, which totaled approximately $8.8 million as of September 30, 2015 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Environmental Matters Substantially all of the Company's properties and land were subject to Phase I Environmental Assessments and when appropriate Phase II Environmental Assessments (collectively, the “Environmental Assessments”) obtained in contemplation of their acquisition by the Company or obtained by predecessor owners prior to the sale of the property or land to the Company. The Environmental Assessments did not reveal, nor is the Company aware of, any non-compliance with environmental laws, environmental liability or other environmental claim that the Company believes would likely have a material adverse effect on the Company. Operating Ground Lease Agreements Future minimum rental payments under the terms of all non-cancelable operating ground leases under which the Company is the lessee, as of September 30, 2015 , were as follows (in thousands): Year Amount 2015 $ 250 2016 998 2017 998 2018 998 2019 998 2020 and thereafter 8,756 Total $ 12,998 Operating ground lease expense for the three and nine months ended September 30, 2015 was $224,000 and $536,000 as compared to $114,000 and $289,000 for the same periods in 2014 , respectively. Legal Matters From time to time, the Company is a party to a variety of legal proceedings, claims and assessments arising in the normal course of business. As of September 30, 2015 there were no legal proceedings, claims or assessments that the Company expects to have a material adverse effect on the Company’s business or financial statements. Other As of September 30, 2015 , the Company had letter of credit obligations of $5.4 million . The Company believes that the likelihood is remote that there will be a draw upon these letter of credit obligations. As of September 30, 2015 , the Company had 27 buildings under development. These buildings are expected to contain, when completed, a total of 6.6 million square feet of leasable space and represent an anticipated aggregate investment of $643.8 million . At September 30, 2015 , development in progress totaled $338.7 million . In addition, as of September 30, 2015 , the Company had invested $12.0 million in deferred leasing costs related to these development buildings. In addition, the Company had a signed commitment for a build-to-suit development not yet commenced for an anticipated investment of $44.9 million . As of September 30, 2015 , the Company was committed to $30.7 million in improvements on certain buildings and land parcels. As of September 30, 2015 , the Company was committed to $51.3 million in future land purchases. As of September 30, 2015 , the Company was obligated to pay for tenant improvements not yet completed for a maximum of $36.2 million . The Company maintains cash and cash equivalents at financial institutions. The combined account balances at each institution typically exceed FDIC insurance coverage and, as a result, there is a concentration of credit risk related to amounts on deposit in excess of FDIC insurance coverage. The Company believes the risk is not significant.

Supplemental Disclosure to Stat

Supplemental Disclosure to Statements of Cash Flows	9 Months Ended
	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure to Statements of Cash Flows	Supplemental Disclosure to Consolidated Statements of Cash Flows The following are supplemental disclosures to the consolidated statements of cash flows for the nine months ended September 30, 2015 and 2014 (amounts in thousands): 2015 2014 Write-off of fully depreciated/amortized property and deferred costs $ 44,216 $ 31,322 Write-off of depreciated/amortized property and deferred costs due to sale/demolition $ 95,277 $ 132,707 Unrealized loss on cash flow hedge $ (1,539 ) $ (990 ) Changes in accrued development capital expenditures $ 5,023 $ 7,854 Increase in investments in and advances to unconsolidated joint ventures $ — $ (11,948 ) Amounts paid in cash for deferred leasing costs incurred in connection with signed leases with tenants are paid in conjunction with improving (acquiring) property, plant and equipment. Such costs are not contained within net real estate. However, they are integral to the completion of a tenant lease and ultimately are related to the improvement and thus the value of the Company’s property, plant and equipment. They are therefore included in investing activities in the Company’s consolidated statements of cash flows.

Organization and Basis of Pre23

Organization and Basis of Presentation (Policy)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Standards In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"), which supersedes nearly all existing revenue recognition guidance. The standard clarifies the required factors that an entity must consider when recognizing revenue. The standard also requires additional disclosures concerning contracts with customers, judgments concerning revenue recognition, and assets recognized for the costs to obtain or fulfill a contract. ASU 2014-09 is effective for the Company beginning January 1, 2018. The Company is evaluating the impact ASU 2014-09 will have on its financial position and results of operations. In April 2015, the FASB issued ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs ("ASU 2015-03") . The standard requires the costs for issuing debt to appear on a balance sheet as a direct deduction from the debt's value. ASU 2015-03 is effective for the Company beginning January 1, 2016. The standard would be applied retrospectively. The Company does not anticipate that the adoption of ASU 2015-03 will have a material impact on its financial position or results of operations. In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis (Topic 810) ("ASU 2015-02"). The standard requires that all entities re-evaluate and revise consolidation documentation for limited partnerships and similar legal entities. It makes changes to both the variable interest model and voting model. ASU 2015-02 is effective for the Company beginning January 1, 2016. The standard allows for either a full retrospective or a modified retrospective approach to adoption. The Company is evaluating the impact ASU 2015-02 will have on its financial position and results of operations.

Income per Common Share of th24

Income per Common Share of the Trust (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): For the Three Months Ended For the Three Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 91,331 148,582 $ 0.61 $ 34,293 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Income from continuing operations net of noncontrolling interest - diluted $ 91,331 149,176 $ 0.61 $ 34,293 148,088 $ 0.23 Discontinued operations net of noncontrolling interest - basic $ — 148,582 $ — $ 130 147,422 $ — Dilutive shares for long-term compensation plans — 594 — 666 Discontinued operations net of noncontrolling interest - diluted $ — 149,176 $ — $ 130 148,088 $ — Net income available to common shareholders - basic $ 91,331 148,582 $ 0.61 $ 34,423 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Net income available to common shareholders - diluted $ 91,331 149,176 $ 0.61 $ 34,423 148,088 $ 0.23 For the Nine Months Ended For the Nine Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 157,797 148,594 $ 1.06 $ 88,430 146,987 $ 0.60 Dilutive shares for long-term compensation plans — 626 — 674 Income from continuing operations net of noncontrolling interest - diluted 157,797 149,220 $ 1.06 88,430 147,661 $ 0.60 Discontinued operations net of noncontrolling interest - basic — 148,594 $ — 47,142 146,987 $ 0.32 Dilutive shares for long-term compensation plans — 626 — 674 Discontinued operations net of noncontrolling interest - diluted — 149,220 $ — 47,142 147,661 $ 0.32 Net income available to common shareholders - basic 157,797 148,594 $ 1.06 135,572 146,987 $ 0.92 Dilutive shares for long-term compensation plans — 626 — 674 Net income available to common shareholders - diluted $ 157,797 149,220 $ 1.06 $ 135,572 147,661 $ 0.92

Income per Common Unit of the25

Income per Common Unit of the Operating Partnership (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Unit, Basic and Diluted [Line Items]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): For the Three Months Ended For the Three Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 91,331 148,582 $ 0.61 $ 34,293 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Income from continuing operations net of noncontrolling interest - diluted $ 91,331 149,176 $ 0.61 $ 34,293 148,088 $ 0.23 Discontinued operations net of noncontrolling interest - basic $ — 148,582 $ — $ 130 147,422 $ — Dilutive shares for long-term compensation plans — 594 — 666 Discontinued operations net of noncontrolling interest - diluted $ — 149,176 $ — $ 130 148,088 $ — Net income available to common shareholders - basic $ 91,331 148,582 $ 0.61 $ 34,423 147,422 $ 0.23 Dilutive shares for long-term compensation plans — 594 — 666 Net income available to common shareholders - diluted $ 91,331 149,176 $ 0.61 $ 34,423 148,088 $ 0.23 For the Nine Months Ended For the Nine Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 157,797 148,594 $ 1.06 $ 88,430 146,987 $ 0.60 Dilutive shares for long-term compensation plans — 626 — 674 Income from continuing operations net of noncontrolling interest - diluted 157,797 149,220 $ 1.06 88,430 147,661 $ 0.60 Discontinued operations net of noncontrolling interest - basic — 148,594 $ — 47,142 146,987 $ 0.32 Dilutive shares for long-term compensation plans — 626 — 674 Discontinued operations net of noncontrolling interest - diluted — 149,220 $ — 47,142 147,661 $ 0.32 Net income available to common shareholders - basic 157,797 148,594 $ 1.06 135,572 146,987 $ 0.92 Dilutive shares for long-term compensation plans — 626 — 674 Net income available to common shareholders - diluted $ 157,797 149,220 $ 1.06 $ 135,572 147,661 $ 0.92
Liberty Property Limited Partnership [Member]
Earnings Per Unit, Basic and Diluted [Line Items]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted income per common unit of the Operating Partnership (in thousands, except per unit amounts): For the Three Months Ended For the Three Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations - net of noncontrolling interest - consolidated joint ventures $ 93,637 $ 35,234 Less: Preferred unit distributions (118 ) (118 ) Income from continuing operations available to common unitholders - basic $ 93,519 152,121 $ 0.61 $ 35,116 150,976 $ 0.23 Dilutive units for long-term compensation plans — 594 — 666 Income from continuing operations available to common unitholders - diluted $ 93,519 152,715 $ 0.61 $ 35,116 151,642 $ 0.23 Income from discontinued operations - basic $ — 152,121 $ — $ 133 150,976 $ — Dilutive units for long-term compensation plans — 594 — 666 Income from discontinued operations - diluted $ — 152,715 $ — $ 133 151,642 $ — Income available to common unitholders - basic $ 93,519 152,121 $ 0.61 $ 35,249 150,976 $ 0.23 Dilutive units for long-term compensation plans — 594 — 666 Income available to common unitholders - diluted $ 93,519 152,715 $ 0.61 $ 35,249 151,642 $ 0.23 For the Nine Months Ended For the Nine Months Ended September 30, 2015 September 30, 2014 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations net of noncontrolling interest - consolidated joint ventures $ 161,914 $ 90,914 Less: Preferred unit distributions (354 ) (354 ) Income from continuing operations available to common unitholders - basic 161,560 152,134 $ 1.06 90,560 150,541 $ 0.60 Dilutive units for long-term compensation plans — 626 — 674 Income from continuing operations available to common unitholders - diluted 161,560 152,760 $ 1.06 90,560 151,215 $ 0.60 Income from discontinued operations - basic — 152,134 $ — 48,276 150,541 $ 0.32 Dilutive units for long-term compensation plans — 626 — 674 Income from discontinued operations - diluted — 152,760 $ — 48,276 151,215 $ 0.32 Income available to common unitholders - basic 161,560 152,134 $ 1.06 138,836 150,541 $ 0.92 Dilutive units for long-term compensation plans — 626 — 674 Income available to common unitholders - diluted $ 161,560 152,760 $ 1.06 $ 138,836 151,215 $ 0.92

Accumulated Other Comprehensi26

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table sets forth the components of Accumulated Other Comprehensive Income (Loss) (in thousands): Nine Months Ended September 30, 2015 2014 Foreign Currency Translation: Beginning balance $ (5,823 ) $ 8,592 Translation adjustment (6,229 ) (5,189 ) Ending balance (12,052 ) 3,403 Derivative Instruments: Beginning balance (377 ) 1,584 Unrealized loss (2,592 ) (2,090 ) Reclassification adjustment (1) 1,053 1,100 Ending balance (1,916 ) 594 Total accumulated other comprehensive (loss) income (13,968 ) 3,997 Less: portion included in noncontrolling interest – operating partnership 131 (290 ) Total accumulated other comprehensive (loss) income included in shareholders' equity/owners' equity $ (13,837 ) $ 3,707 (1) Amounts reclassified out of Accumulated Other Comprehensive (Loss) Income/General & Limited Partner's Equity into contractual interest expense.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting, Measurement Disclosures [Abstract]
Schedule of Segment Reporting Information, by Segment, Revenue and Net Operating Income [Table Text Block]	The operating information by reportable segment is as follows (in thousands): For the Three Months For the Nine Months Ended September 30, Ended September 30, 2015 2014 2015 2014 Operating revenue Carolinas $ 10,555 $ 9,479 $ 30,462 $ 26,282 Chicago/Milwaukee 8,872 8,004 27,596 24,727 Houston 12,981 12,833 38,455 36,828 Lehigh/Central PA 33,746 30,034 100,144 87,853 Minnesota 11,751 13,925 36,699 41,217 Orlando 5,547 8,463 16,221 24,519 Philadelphia 10,552 8,303 30,422 26,402 Richmond/Hampton Roads 5,168 10,358 25,809 30,542 South Florida 12,957 12,012 37,542 36,028 Southeastern PA 36,718 36,087 114,430 110,833 Tampa 13,568 13,597 40,667 40,001 United Kingdom 3,776 4,111 11,466 12,430 Other 32,801 31,144 99,636 96,300 Segment-level operating revenue 198,992 198,350 609,549 593,962 Reconciliation to total operating revenues Discontinued operations — (9 ) — (4,728 ) Other (20 ) 15 (157 ) (288 ) Total operating revenue $ 198,972 $ 198,356 $ 609,392 $ 588,946 Net operating income Carolinas $ 7,795 $ 6,570 $ 21,479 $ 18,006 Chicago/Milwaukee 5,792 5,382 18,660 15,518 Houston 7,829 7,510 22,739 21,794 Lehigh/Central PA 24,289 21,634 70,907 60,647 Minnesota 4,461 6,575 15,595 19,964 Orlando 3,835 5,411 11,091 16,257 Philadelphia 7,898 6,736 22,230 20,247 Richmond/Hampton Roads 3,014 6,144 15,538 18,118 South Florida 7,012 6,647 20,990 21,066 Southeastern PA 20,887 20,516 63,301 60,175 Tampa 8,454 8,213 25,780 25,142 United Kingdom 2,619 2,468 7,917 8,040 Other 21,750 20,715 66,138 61,614 Segment-level net operating income 125,635 124,521 382,365 366,588 Reconciliation to income from continuing operations Interest expense (1) (33,559 ) (37,958 ) (103,295 ) (116,192 ) Depreciation/amortization expense (1) (2) (40,870 ) (44,538 ) (126,162 ) (133,636 ) Impairment - real estate assets — — (16,775 ) — Gain (loss) on property dispositions 53,467 (20 ) 56,987 1,878 Equity in (loss) earnings of unconsolidated joint ventures (847 ) 1,592 805 7,297 General and administrative expense (1) (2) (9,456 ) (8,556 ) (33,043 ) (29,189 ) Discontinued operations excluding interest and gain on property dispositions — (95 ) — (2,541 ) Income taxes (2) (526 ) (821 ) (2,283 ) (1,966 ) Other (149 ) 1,193 3,486 (851 ) Income from continuing operations $ 93,695 $ 35,318 $ 162,085 $ 91,388 (1) Includes activity on discontinued operations. (2) Excludes costs which are included in determining segment-level net operating income.
Real Estate Properties Sold [Table Text Block]	The Company's sales by reportable segment for the three and nine months ended September 30, 2015 are as follows: Three months ended September 30, 2015 Nine months ended September 30, 2015 Properties Sold Square Feet (000s) Gross Proceeds (000s) Properties Sold Square Feet (000s) Gross Proceeds (000s) Minnesota 1 135 $ 19,900 2 223 $ 25,700 Richmond/Hampton Roads — — — 22 1,319 110,300 (1) Southeastern PA 3 250 63,500 4 333 72,220 Tampa 1 32 2,525 1 32 2,525 Other 1 31 3,859 7 569 37,371 Total 6 448 $ 89,784 36 2,476 $ 248,116 (1) Includes proceeds from the sale of 3.1 acres of land.
Assets by Segment and Reconciliation to Consolidated[Table Text Block]	The Company's total assets by reportable segment as of September 30, 2015 and December 31, 2014 is as follows (in thousands): September 30, 2015 December 31, 2014 Total assets Carolinas $ 336,634 $ 325,690 Chicago/Milwaukee 426,729 422,531 Houston 520,128 418,154 Lehigh/Central PA 1,094,009 1,023,641 Minnesota 321,194 333,506 Orlando 160,020 160,899 Philadelphia 416,373 366,577 Richmond/Hampton Roads 126,909 250,205 South Florida 419,008 400,034 Southeastern PA 658,063 698,163 Tampa 329,687 335,652 United Kingdom 219,362 231,276 Other 1,577,732 1,553,250 Segment-level total assets 6,605,848 6,519,578 Corporate Other 83,945 105,958 Total assets $ 6,689,793 $ 6,625,536

Accounting for the Impairment28

Accounting for the Impairment or Disposal of Long-Lived Assets (Tables)	9 Months Ended
	Sep. 30, 2015
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Discontinued Operations, Income Statement [Table Text Block]	A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenues $ — $ 9 $ — $ 4,728 Operating expenses — 86 — (2,226 ) Interest and other income — — — 39 Interest expense — — — (557 ) Depreciation and amortization — — — — Income before gain on property dispositions — 95 — 1,984 Gain on property dispositions — 38 — 46,292 Net income $ — $ 133 $ — $ 48,276

Noncontrolling Interest - Ope29

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Tables)	9 Months Ended
	Sep. 30, 2015
Temporary Equity [Line Items]
Schedule of Temporary Equity [Table Text Block]	As of September 30, 2015 , the Company had outstanding the following cumulative preferred units of the Operating Partnership: ISSUE AMOUNT UNITS LIQUIDATION PREFERENCE DIVIDEND RATE (in 000’s) Series I-2 $ 7,537 301 $25 6.25 %

Disclosure of Fair Value of F30

Disclosure of Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Instrument, Fair Value Disclosure [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following summarizes the fair value of the Company's mortgage loans and unsecured notes as of December 31, 2014 and September 30, 2015 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2014 $ 487,301 $ 501,231 $ 2,509,094 $ 2,704,069 As of September 30, 2015 $ 372,660 $ 381,500 $ 2,608,307 $ 2,621,855

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Gain (Loss) [Table Text Block]	The following table presents the location in the financial statements of the gains or losses recognized related to the Company’s cash flow hedges for the three and nine months ended September 30, 2015 and 2014: Three Months Ended Nine Months Ended September 30, 2015 September 30, 2014 September 30, 2015 September 30, 2014 (in thousands) Amount of (loss) gain related to the effective portion recognized in other comprehensive (loss) income $ (1,570 ) $ 299 $ (2,592 ) $ (2,083 ) Amount of (loss) gain related to the effective portion subsequently reclassified to earnings $ (350 ) $ (367 ) $ (1,053 ) $ (1,093 ) Amount of (loss) gain related to the ineffective portion $ (51 ) $ 13 $ (113 ) $ (42 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Rental Payments	Future minimum rental payments under the terms of all non-cancelable operating ground leases under which the Company is the lessee, as of September 30, 2015 , were as follows (in thousands): Year Amount 2015 $ 250 2016 998 2017 998 2018 998 2019 998 2020 and thereafter 8,756 Total $ 12,998

Supplemental Disclosure to St33

Supplemental Disclosure to Statements of Cash Flows (Tables)	9 Months Ended
	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure to Statements of Cash Flows	The following are supplemental disclosures to the consolidated statements of cash flows for the nine months ended September 30, 2015 and 2014 (amounts in thousands): 2015 2014 Write-off of fully depreciated/amortized property and deferred costs $ 44,216 $ 31,322 Write-off of depreciated/amortized property and deferred costs due to sale/demolition $ 95,277 $ 132,707 Unrealized loss on cash flow hedge $ (1,539 ) $ (990 ) Changes in accrued development capital expenditures $ 5,023 $ 7,854 Increase in investments in and advances to unconsolidated joint ventures $ — $ (11,948 )

Organization and Basis of Pre34

Organization and Basis of Presentation (Details) - USD ($)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Organization [Abstract]
Ownership interest in operating partnership - Limited Partnership		97.70%
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Common shares of beneficial interest		$ 148,000	$ 149,000
Additional paid-in capital		$ 3,673,001,000	3,688,644,000
Parent balance sheet, equity reclassification [Member] | Adjustment to prior period balance [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Common shares of beneficial interest			(1,000)
Additional paid-in capital			(51,900,000)
Impact of Error on Income Statement	$ 0
Impact of Error on Statement of Cash Flow	0
Parent balance sheet, equity reclassification [Member] | Previously reported amounts [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Common shares of beneficial interest			150,000
Additional paid-in capital			3,740,600,000
Liberty Property Limited Partnership [Member] | Parent balance sheet, equity reclassification [Member] | Adjustment to prior period balance [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Impact of Error on Income Statement	0
Impact of Error on Statement of Cash Flow	$ 0
Impact of Error on Balance Sheet			$ 0

Income per Common Share of th35

Income per Common Share of the Trust (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest	$ 91,331	$ 34,293	$ 157,797	$ 88,430
Discontinued operations net of noncontrolling interest	0	130	0	47,142
Net income available to common shareholders	$ 91,331	$ 34,423	$ 157,797	$ 135,572
Weighted Average Shares (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	148,582	147,422	148,594	146,987
Dilutive shares for long-term compensation plans	594	666	626	674
Weighted Average Number of Shares Outstanding, Diluted	149,176	148,088	149,220	147,661
Common shares [Member]
Earnings Per Share, Basic [Abstract]
Income from Continuing Operations, Per Basic Share	$ 0.61	$ 0.23	$ 1.06	$ 0.60
Income from Discontinued Operations, Per Basic Share	0	0	0	0.32
Income per common share - basic	0.61	0.23	1.06	0.92
Earnings Per Share, Diluted [Abstract]
Income from Continuing Operations, Per Diluted Share	0.61	0.23	1.06	0.60
Income from Discontinued Operations, Per Diluted Share	0	0	0	0.32
Income per common share - diluted	$ 0.61	$ 0.23	$ 1.06	$ 0.92

Income per Common Share of th36

Income per Common Share of the Trust Income per Common Share of the Trust - Anti-dilutive Options (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stock Option [Member]
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Options Excluded from Computation of Earnings Per Share	2,260,000	1,183,000	1,528,000	850,000

Income per Common Share of th37

Income per Common Share of the Trust - Options Exercised (Details) - shares	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
Stock Option [Member] | Common shares [Member]
Stock Option Exercises [Line Items]
Amount of Options Exercises in Period	12,000	65,000	44,000

Income per Common Share of th38

Income per Common Share of the Trust - Share Repurchase (Details) - Common shares [Member] - 2015 Share Repurchase Program [Member] $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015USD ($)shares	Sep. 30, 2015USD ($)shares
Class of Stock [Line Items]
Authorized amount of shares available to be repurchased under a share repurchase plan	$ 250	$ 250
Number of shares repurchased during period | shares	2,125,000	2,125,000
Amount paid for repurchase of shares	$ 65.5	$ 65.5

Income per Common Unit of the39

Income per Common Unit of the Operating Partnership - Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$ 91,331	$ 34,293	$ 157,797	$ 88,430
Income from discontinued operations	0	133	0	48,276
Net income available to common shareholders	$ 91,331	$ 34,423	$ 157,797	$ 135,572
Weighted Average Units (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	148,582	147,422	148,594	146,987
Dilutive units for long-term compensation plans	594	666	626	674
Weighted Average Number of Shares Outstanding, Diluted	149,176	148,088	149,220	147,661
Liberty Property Limited Partnership [Member]
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$ 93,637	$ 35,234	$ 161,914	$ 90,914
Less: Preferred unit distributions	(118)	(118)	(354)	(354)
Income from Continuing Operations available to Common Unitholders	93,519	35,116	161,560	90,560
Income from discontinued operations	0	133	0	48,276
Net income available to common shareholders	$ 93,519	$ 35,249	$ 161,560	$ 138,836
Weighted Average Units (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	152,121	150,976	152,134	150,541
Dilutive units for long-term compensation plans	594	666	626	674
Weighted Average Number of Shares Outstanding, Diluted	152,715	151,642	152,760	151,215
Liberty Property Limited Partnership [Member] | Common Units [Member]
Earnings Per Unit, Basic [Abstract]
Income from Continuing Operations, Per Basic Share	$ 0.61	$ 0.23	$ 1.06	$ 0.60
Income from Discontinued Operations, Per Basic Share	0	0	0	0.32
Income per common share - basic	0.61	0.23	1.06	0.92
Earnings Per Unit, Diluted [Abstract]
Income from Continuing Operations, Per Diluted Share	0.61	0.23	1.06	0.60
Income from Discontinued Operations, Per Diluted Share	0	0	0	0.32
Income per common share - diluted	$ 0.61	$ 0.23	$ 1.06	$ 0.92

Income per Common Unit of the40

Income per Common Unit of the Operating Partnership - Anti-dilutive Options (Details) - Stock Option [Member] - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Options Excluded from Computation of Earnings Per Share	2,260,000	1,183,000	1,528,000	850,000
Liberty Property Limited Partnership [Member]
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Options Excluded from Computation of Earnings Per Share	2,260,000	1,183,000	1,528,000	850,000

Income per Common Unit of the41

Income per Common Unit of the Operations Partnership - Options Exercised (Details) - shares	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
Liberty Property Limited Partnership [Member] | Stock Option [Member] | Common Units [Member]
Stock Option Exercises [Line Items]
Amount of Options Exercises in Period	12,000	65,000	44,000

Income per Common Unit of the42

Income per Common Unit of the Operating Partnership - Unit Repurchase (Details) - Liberty Property Limited Partnership [Member] - Common Units [Member] - 2015 Share Repurchase Program [Member] $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015USD ($)shares	Sep. 30, 2015USD ($)shares
Class of Stock [Line Items]
Authorized amount of shares available to be repurchased under a share repurchase plan	$ 250	$ 250
Number of units repurchased during period | shares	2,125,000	2,125,000
Amount paid for repurchase of units	$ 65.5	$ 65.5

Accumulated Other Comprehensi43

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		$ 3,086,377
Ending Balance		3,007,109
Total accumulated other comprehensive (loss) income		3,086,377		$ 3,007,109	$ 3,086,377
Total accumulated other comprehensive (loss) income included in shareholders' equity/owners' equity				2,950,221	3,027,672
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(5,823)	$ 8,592
Other comprehensive income (loss), before reclassifications		(6,229)	(5,189)
Ending Balance		(12,052)	3,403
Total accumulated other comprehensive (loss) income		(5,823)	8,592	(12,052)	(5,823)	$ 3,403
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(377)	1,584
Other comprehensive income (loss), before reclassifications		(2,592)	(2,090)
Reclassification adjustment	[1]	1,053	1,100
Ending Balance		(1,916)	594
Total accumulated other comprehensive (loss) income		(377)	1,584	(1,916)	(377)	594
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		(13,968)	3,997
Total accumulated other comprehensive (loss) income		(13,968)	3,997	(13,968)		3,997
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		131	(290)
Total accumulated other comprehensive (loss) income		131	$ (290)	131		(290)
AOCI Attributable to Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(6,252)
Ending Balance		(13,837)
Total accumulated other comprehensive (loss) income		$ (6,252)		(13,837)	$ (6,252)
Total accumulated other comprehensive (loss) income included in shareholders' equity/owners' equity				$ (13,837)		$ 3,707
[1]	Amounts reclassified out of Accumulated Other Comprehensive (Loss) Income/General & Limited Partner's Equity into contractual interest expense.

Performance of the Reportable S

Performance of the Reportable Segments Based on Property Level Operating Income (Details) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Operating revenue		$ 198,972,000	$ 198,356,000	$ 609,392,000	$ 588,946,000
Net operating income		70,274,000	66,330,000	192,290,000	188,145,000
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense		(33,559,000)	(37,958,000)	(103,295,000)	(115,635,000)
Depreciation and amortization expense				(173,726,000)	(176,207,000)
Impairment - real estate assets		0	0	(16,775,000)	0
Gain (loss) on property dispositions		53,467,000	(20,000)	56,987,000	1,878,000
Equity in (loss) earnings of unconsolidated joint ventures		(847,000)	1,592,000	805,000	7,297,000
General and administrative expense		(15,573,000)	(14,748,000)	(51,428,000)	(48,077,000)
Income taxes		(599,000)	(859,000)	(2,613,000)	(2,083,000)
Income from continuing operations		93,695,000	35,318,000	162,085,000	91,388,000
Richmond Hampton Roads [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Impairment - real estate assets				(13,400,000)
Southeastern PA [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Impairment - real estate assets				(2,300,000)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenue		0	0	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenue		198,992,000	198,350,000	609,549,000	593,962,000
Net operating income		125,635,000	124,521,000	382,365,000	366,588,000
Operating Segments [Member] | Carolinas [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		10,555,000	9,479,000	30,462,000	26,282,000
Net operating income		7,795,000	6,570,000	21,479,000	18,006,000
Operating Segments [Member] | Chicago Milwaukee [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		8,872,000	8,004,000	27,596,000	24,727,000
Net operating income		5,792,000	5,382,000	18,660,000	15,518,000
Operating Segments [Member] | Houston [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		12,981,000	12,833,000	38,455,000	36,828,000
Net operating income		7,829,000	7,510,000	22,739,000	21,794,000
Operating Segments [Member] | Lehigh Central PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		33,746,000	30,034,000	100,144,000	87,853,000
Net operating income		24,289,000	21,634,000	70,907,000	60,647,000
Operating Segments [Member] | Minnesota [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		11,751,000	13,925,000	36,699,000	41,217,000
Net operating income		4,461,000	6,575,000	15,595,000	19,964,000
Operating Segments [Member] | Orlando [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		5,547,000	8,463,000	16,221,000	24,519,000
Net operating income		3,835,000	5,411,000	11,091,000	16,257,000
Operating Segments [Member] | Philadelphia [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		10,552,000	8,303,000	30,422,000	26,402,000
Net operating income		7,898,000	6,736,000	22,230,000	20,247,000
Operating Segments [Member] | Richmond Hampton Roads [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		5,168,000	10,358,000	25,809,000	30,542,000
Net operating income		3,014,000	6,144,000	15,538,000	18,118,000
Operating Segments [Member] | South Florida [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		12,957,000	12,012,000	37,542,000	36,028,000
Net operating income		7,012,000	6,647,000	20,990,000	21,066,000
Operating Segments [Member] | Southeastern PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		36,718,000	36,087,000	114,430,000	110,833,000
Net operating income		20,887,000	20,516,000	63,301,000	60,175,000
Operating Segments [Member] | Tampa [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		13,568,000	13,597,000	40,667,000	40,001,000
Net operating income		8,454,000	8,213,000	25,780,000	25,142,000
Operating Segments [Member] | United Kingdom [Member] | UNITED KINGDOM
Segment Reporting Information [Line Items]
Operating revenue		3,776,000	4,111,000	11,466,000	12,430,000
Net operating income		2,619,000	2,468,000	7,917,000	8,040,000
Operating Segments [Member] | Other Segments [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		32,801,000	31,144,000	99,636,000	96,300,000
Net operating income		21,750,000	20,715,000	66,138,000	61,614,000
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Operating revenue		0	(9,000)	0	(4,728,000)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenue		(20,000)	15,000	(157,000)	(288,000)
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	[1]	(33,559,000)	(37,958,000)	(103,295,000)	(116,192,000)
Depreciation and amortization expense	[1],[2]	(40,870,000)	(44,538,000)	(126,162,000)	(133,636,000)
Impairment - real estate assets		0	0	(16,775,000)	0
Gain (loss) on property dispositions		53,467,000	(20,000)	56,987,000	1,878,000
Equity in (loss) earnings of unconsolidated joint ventures		(847,000)	1,592,000	805,000	7,297,000
General and administrative expense	[1],[2]	(9,456,000)	(8,556,000)	(33,043,000)	(29,189,000)
Discontinued operations excluding interest and gain on property dispositions		0	(95,000)	0	(2,541,000)
Income taxes	[2]	(526,000)	(821,000)	(2,283,000)	(1,966,000)
Other		$ (149,000)	$ 1,193,000	$ 3,486,000	$ (851,000)
[1]	Includes activity on discontinued operations.
[2]	Excludes costs which are included in determining segment-level net operating income.

Segment Information Building Ac

Segment Information Building Acquisitions and Dispositions (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015USD ($)ft²abldg	Sep. 30, 2015USD ($)ft²abldg
Land, Buildings and Improvements [Member]
Dispositions [Abstract]
Number of Real Estate Properties Sold	6	36
Sold Real Estate Property, Square Feet | ft²	448,000	2,476,000
Proceeds from Sale of Property | $	$ 89,784	$ 248,116
Houston [Member] | Land and Land Improvements [Member]
Acquisitions [Abstract]
Land acquired, acres | a	139
Houston [Member] | Land, Buildings and Improvements [Member]
Acquisitions [Abstract]
Number of real estate properties acquired	3
Acquired Real Estate Property, Square Feet | ft²	921,000
Payments to Acquire Commercial Real Estate | $	$ 86,600
Minnesota [Member] | Land, Buildings and Improvements [Member]
Dispositions [Abstract]
Number of Real Estate Properties Sold	1	2
Sold Real Estate Property, Square Feet | ft²	135,000	223,000
Proceeds from Sale of Property | $	$ 19,900	$ 25,700
Richmond Hampton Roads [Member] | Land and Land Improvements [Member]
Dispositions [Abstract]
Sold Land, Acres | a		3.1
Richmond Hampton Roads [Member] | Land, Buildings and Improvements [Member]
Dispositions [Abstract]
Number of Real Estate Properties Sold	0	22
Sold Real Estate Property, Square Feet | ft²	0	1,319,000
Proceeds from Sale of Property | $	$ 0	$ 110,300	[1]
Southeastern PA [Member] | Land, Buildings and Improvements [Member]
Dispositions [Abstract]
Number of Real Estate Properties Sold	3	4
Sold Real Estate Property, Square Feet | ft²	250,000	333,000
Proceeds from Sale of Property | $	$ 63,500	$ 72,220
Tampa [Member] | Land, Buildings and Improvements [Member]
Dispositions [Abstract]
Number of Real Estate Properties Sold	1	1
Sold Real Estate Property, Square Feet | ft²	32,000	32,000
Proceeds from Sale of Property | $	$ 2,525	$ 2,525
Other Segments [Member] | Land, Buildings and Improvements [Member]
Dispositions [Abstract]
Number of Real Estate Properties Sold	1	7
Sold Real Estate Property, Square Feet | ft²	31,000	569,000
Proceeds from Sale of Property | $	$ 3,859	$ 37,371
Southern California and Houston [Member] | Land and Land Improvements [Member]
Acquisitions [Abstract]
Land acquired, acres | a		139
Southern California and Houston [Member] | Land, Buildings and Improvements [Member]
Acquisitions [Abstract]
Number of real estate properties acquired		4
Acquired Real Estate Property, Square Feet | ft²		1,300,000
Payments to Acquire Commercial Real Estate | $		$ 123,400
[1]	Includes proceeds from the sale of 3.1 acres of land.

Segment Information Related Par

Segment Information Related Party (Details) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2015USD ($)bldg	Sep. 30, 2015USD ($)abldg
Land, Buildings and Improvements [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties Sold in a Related Party Transaction		6	36
Proceeds from Sale of Property in a Related Party Transaction | $		$ 89,784	$ 248,116
Land, Buildings and Improvements [Member] | Richmond Hampton Roads [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties Sold in a Related Party Transaction		0	22
Proceeds from Sale of Property in a Related Party Transaction | $		$ 0	$ 110,300	[1]
Land, Buildings and Improvements [Member] | Richmond Hampton Roads [Member] | Immediate Family Member of Management or Principal Owner [Member] | Richmond Hampton Roads Sale [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties Sold in a Related Party Transaction			22
Proceeds from Sale of Property in a Related Party Transaction | $	[1]		$ 110,300
Land and Land Improvements [Member] | Richmond Hampton Roads [Member]
Related Party Transaction [Line Items]
Sold Land, Acres | a			3.1
Land and Land Improvements [Member] | Richmond Hampton Roads [Member] | Immediate Family Member of Management or Principal Owner [Member] | Richmond Hampton Roads Sale [Member]
Related Party Transaction [Line Items]
Sold Land, Acres | a			3.1
[1]	Includes proceeds from the sale of 3.1 acres of land.

Segment Information Total Asset

Segment Information Total Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Assets	$ 6,689,793	$ 6,625,536
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	6,605,848	6,519,578
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Assets	83,945	105,958
North America [Member] | Operating Segments [Member] | Carolinas [Member]
Segment Reporting Information [Line Items]
Assets	336,634	325,690
North America [Member] | Operating Segments [Member] | Chicago Milwaukee [Member]
Segment Reporting Information [Line Items]
Assets	426,729	422,531
North America [Member] | Operating Segments [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Assets	520,128	418,154
North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Assets	1,094,009	1,023,641
North America [Member] | Operating Segments [Member] | Minnesota [Member]
Segment Reporting Information [Line Items]
Assets	321,194	333,506
North America [Member] | Operating Segments [Member] | Orlando [Member]
Segment Reporting Information [Line Items]
Assets	160,020	160,899
North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Assets	416,373	366,577
North America [Member] | Operating Segments [Member] | Richmond Hampton Roads [Member]
Segment Reporting Information [Line Items]
Assets	126,909	250,205
North America [Member] | Operating Segments [Member] | South Florida [Member]
Segment Reporting Information [Line Items]
Assets	419,008	400,034
North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Assets	658,063	698,163
North America [Member] | Operating Segments [Member] | Tampa [Member]
Segment Reporting Information [Line Items]
Assets	329,687	335,652
North America [Member] | Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Assets	1,577,732	1,553,250
UNITED KINGDOM | Operating Segments [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Assets	$ 219,362	$ 231,276

Accounting for the Impairment48

Accounting for the Impairment or Disposal of Long-Lived Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Discontinued Operations, Income Statement [Line Items]
Gain on property dispositions	$ 0	$ 38	$ 0	$ 46,292
Net income	0	133	0	48,276
Discontinued Operations [Member]
Discontinued Operations, Income Statement [Line Items]
Revenues	0	9	0	4,728
Operating expenses	0	86	0	(2,226)
Interest and other income	0	0	0	39
Interest expense	0	0	0	(557)
Depreciation and amortization	0	0	0	0
Income before gain on property dispositions	0	95	0	1,984
Gain on property dispositions	0	38	0	46,292
Net income	$ 0	$ 133	$ 0	$ 48,276

Accounting for the Impairment49

Accounting for the Impairment or Disposal of Long-Lived Assets Asset Impairment (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment [Line Items]
Impairment - real estate assets	$ 0	$ 0	$ 16,775,000	$ 0
Maryland [Member]
Property, Plant and Equipment [Line Items]
Impairment - real estate assets			1,000,000
Richmond Hampton Roads [Member]
Property, Plant and Equipment [Line Items]
Impairment - real estate assets			13,400,000
Southeastern PA [Member]
Property, Plant and Equipment [Line Items]
Impairment - real estate assets			$ 2,300,000

Noncontrolling Interests of t50

Noncontrolling Interests of the Trust- Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Redeemable Noncontrolling Interest [Line Items]
Limited Partners' common units outstanding	3,539,075	3,553,566
Market value of common units based on closing price	$ 111.5
Liberty Property Limited Partnership [Member]
Redeemable Noncontrolling Interest [Line Items]
Limited Partners' common units outstanding	3,539,075	3,553,566

Limited Partners' Equity of t51

Limited Partners' Equity of the Operating Partnership - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Limited Partners' Capital Account [Line Items]
Limited Partners' common units outstanding	3,539,075	3,553,566
Liberty Property Limited Partnership [Member]
Limited Partners' Capital Account [Line Items]
Limited Partners' common units outstanding	3,539,075	3,553,566
market value of the outstanding common units	$ 111.5

Noncontrolling Interest - Ope52

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Temporary Equity [Line Items]
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2015 and December 31, 2014	$ 7,537	$ 7,537
Series I 2 [Member]
Temporary Equity [Line Items]
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2015 and December 31, 2014	$ 7,537
Units	301,483	301,483
Liquidation Preference	$ 25
Dividend Rate	6.25%

Indebtedness (Details)

Indebtedness (Details) - USD ($) $ in Millions	Aug. 01, 2015	Mar. 01, 2015
Senior Notes [Member] | 5.125% Senior Notes [Member]
Unsecured Notes [Abstract]
Debt Instrument, Repurchased Face Amount		$ 300
Interest Rate		5.125%
Senior Notes [Member] | 3.75% Senior Notes [Member]
Unsecured Notes [Abstract]
Debt Instrument, Face Amount		$ 400
Interest Rate		3.75%
Mortgages [Member] | 7.0% Mortgage [Member]
Unsecured Notes [Abstract]
Debt Instrument, Repurchased Face Amount	$ 105.8
Interest Rate	7.00%

Disclosure of Fair Value of F54

Disclosure of Fair Value of Financial Instruments (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Estimate of Fair Value Measurement [Member] | Mortgage Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 381,500	$ 501,231
Estimate of Fair Value Measurement [Member] | Unsecured Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	2,621,855	2,704,069
Portion at Other than Fair Value Measurement [Member] | Mortgage Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	372,660	487,301
Portion at Other than Fair Value Measurement [Member] | Unsecured Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 2,608,307	$ 2,509,094

Unconsolidated Joint Ventures (

Unconsolidated Joint Ventures (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)ft²roomstorybldginvestment	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)ft²roomstorybldginvestment	Sep. 30, 2014USD ($)
Liberty Washington LP [Abstract]
Impairment - real estate assets	$ 0	$ 0	$ 16,775,000	$ 0
Land, Buildings and Improvements [Member]
LIberty Venture I LP [Abstract]
Proceeds from Sale of Property	$ 89,784,000		$ 248,116,000
Number of Real Estate Properties Sold | bldg	6		36
Sold Real Estate Property, Square Feet | ft²	448,000		2,476,000
Construction in Progress [Member]
Comcast Innovative and Technology Center [Abstract]
Net Rentable Area | ft²	6,600,000		6,600,000
Total anticipated development cost	$ 643,800,000		$ 643,800,000
Liberty Washington, LP [Member] | Northern Virginia [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%
Liberty Washington, LP [Member] | Northern Virginia [Member] | Mortgages [Member]
Liberty Washington LP [Abstract]
Debt Instrument, Debt Default, Amount	$ 46,400,000		$ 46,400,000
Comcast Innovation and Technology Center [Member] | Construction in Progress [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	20.00%		20.00%
Comcast Innovative and Technology Center [Abstract]
Number of equity method investments | investment	2		2
Number of stories in a high-rise building | story	59		59
Net Rentable Area | ft²	1,300,000		1,300,000
Number of hotel rooms | room	222		222
Total anticipated development cost	$ 932,000,000		$ 932,000,000
Anticipated investment in joint ventures	$ 185,000,000		$ 185,000,000
Liberty Venture I, LP [Member] | New Jersey [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%
Liberty Venture I, LP [Member] | New Jersey [Member] | Land, Buildings and Improvements [Member]
LIberty Venture I LP [Abstract]
Proceeds from Sale of Property			$ 8,500,000
Number of Real Estate Properties Sold | bldg			1
Sold Real Estate Property, Square Feet | ft²			198,000
Gain (Loss) on Investments [Member] | Company's portion [Member] | Fair Value, Inputs, Level 2 [Member] | Liberty Washington, LP [Member] | Northern Virginia [Member]
Liberty Washington LP [Abstract]
Impairment - real estate assets	$ 3,900,000		$ 11,500,000

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Interest Rate Derivatives [Abstract]
Number of interest rate swap contracts	3		3
aggregate notional amount	$ 102,000		$ 102,000		$ 103,600
Termination value of interest rate swap, including accrued interest	8,800		8,800
Interest Rate Cash Flow Hedges [Abstract]
Fair value of interest rate swaps	8,700		8,700		$ 8,500
Amount estimated to be reclassified from accumulated other comprehensive income as an increase to interest expense	1,200		1,200
Interest Rate Swap [Member] | Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain related to the effective portion recognized in other comprehensive (loss) income	(1,570)	$ 299	(2,592)	$ (2,083)
Interest Rate Swap [Member] | Interest Expense [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain related to the effective portion subsequently reclassified to earnings	(350)	(367)	(1,053)	(1,093)
Amount of (loss) gain related to the ineffective portion	$ (51)	$ 13	$ (113)	$ (42)

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Rental Payments (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
2,015	$ 250,000		$ 250,000
2,016	998,000		998,000
2,017	998,000		998,000
2,018	998,000		998,000
2,019	998,000		998,000
2020 through 2034	8,756,000		8,756,000
Total	12,998,000		12,998,000
Other Expenses [Abstract]
Operating ground lease expense	$ 224,000	$ 114,000	$ 536,000	$ 289,000

Commitments and Contingencies58

Commitments and Contingencies - Loss Contingencies (Details) $ in Millions	Sep. 30, 2015USD ($)
Legal Matters [Abstract]
Loss Contingency, Pending Claims, Number	0
Other [Abstract]
Letter of credit obligations	$ 5.4

Commitments and Contingencies59

Commitments and Contingencies - Supply Commitments (Details) $ in Thousands, ft² in Millions	Sep. 30, 2015USD ($)ft²properties	Dec. 31, 2014USD ($)
Supply Commitment [Line Items]
Development in Process	$ 338,673	$ 277,411
Construction in Progress [Member]
Supply Commitment [Line Items]
Net Rentable Area | ft²	6.6
Number of Real Estate Properties | properties	27
Total anticipated development cost	$ 643,800
Deferred Costs, Leasing, Gross	12,000
Development Not Yet Commenced [Member]
Supply Commitment [Line Items]
Total anticipated development cost	44,900
Buildings and land parcels [Member]
Supply Commitment [Line Items]
Remaining amount committed or obligated to pay for the benefit of current or future tenants	30,700
Tenant Improvements [Member]
Supply Commitment [Line Items]
Tenant improvements not yet completed	$ 36,200

Commitments and Contingencies60

Commitments and Contingencies - Purchase Commitments (Details) $ in Millions	Sep. 30, 2015USD ($)
Land Purchases [Member]
Long-term Purchase Commitment [Line Items]
Remaining amount commitment to future land purchases	$ 51.3

Supplemental Disclosure to St61

Supplemental Disclosure to Statements of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Supplemental Cash Flow Information [Abstract]
Write-off of fully depreciated/amortized property and deferred costs	$ 44,216	$ 31,322
Write-off of depreciated/amortized property and deferred costs due to sale/demolition	95,277	132,707
Unrealized loss on cash flow hedge	(1,539)	(990)
Changes in accrued development capital expenditures	5,023	7,854
Increase in investments in and advances to unconsolidated joint ventures	$ 0	$ (11,948)