Liberty Property Trust (LPT) 10-Q 3 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2016	Nov. 01, 2016
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, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		146,993,579
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, 2016	Dec. 31, 2015
Real Estate [Abstract]
Land and land improvements	$ 1,009,941	$ 1,184,927
Building and improvements	4,409,422	5,131,648
Less accumulated depreciation	(917,201)	(1,148,928)
Operating real estate	4,502,162	5,167,647
Development in progress	427,686	360,948
Land held for development	325,444	336,967
Net real estate	5,255,292	5,865,562
Cash and cash equivalents	42,290	35,353
Restricted cash	5,661	9,018
Accounts receivable	13,983	14,343
Deferred rent receivable	106,864	118,787
Deferred financing and leasing costs, net of accumulated amortization (September 30, 2016, $153,022; December 31, 2015, $175,798)	153,593	192,109
Investments in and advances to unconsolidated joint ventures	236,800	218,454
Assets held for sale	786,272	4,954
Prepaid expenses and other assets	122,167	99,049
Total assets	6,722,922	6,557,629
LIABILITIES
Mortgage loans	281,384	307,908
Unsecured notes	2,675,644	2,580,108
Credit facility	420,000	259,000
Accounts payable	76,599	51,382
Accrued interest	38,954	26,154
Dividend and distributions payable	71,378	71,787
Other liabilities	204,031	243,806
Liabilities held for sale	25,416	0
Total liabilities	3,793,406	3,540,145
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2016 and December 31, 2015	7,537	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 146,981,465 and 147,577,984 shares issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	147	148
Additional paid-in capital	3,654,652	3,669,627
Accumulated other comprehensive loss	(41,459)	(17,893)
Distributions in excess of net income	(746,530)	(698,954)
Total Liberty Property Trust shareholders' equity	2,866,810	2,952,928
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	51,250	53,100
Noncontrolling interest - consolidated joint ventures	3,919	3,919
Total owners' equity	2,921,979	3,009,947
Total liabilities, noncontrolling interest - operating partnership and equity	6,722,922	6,557,629
Liberty Property Limited Partnership [Member]
Real Estate [Abstract]
Land and land improvements	1,009,941	1,184,927
Building and improvements	4,409,422	5,131,648
Less accumulated depreciation	(917,201)	(1,148,928)
Operating real estate	4,502,162	5,167,647
Development in progress	427,686	360,948
Land held for development	325,444	336,967
Net real estate	5,255,292	5,865,562
Cash and cash equivalents	42,290	35,353
Restricted cash	5,661	9,018
Accounts receivable	13,983	14,343
Deferred rent receivable	106,864	118,787
Deferred financing and leasing costs, net of accumulated amortization (September 30, 2016, $153,022; December 31, 2015, $175,798)	153,593	192,109
Investments in and advances to unconsolidated joint ventures	236,800	218,454
Assets held for sale	786,272	4,954
Prepaid expenses and other assets	122,167	99,049
Total assets	6,722,922	6,557,629
LIABILITIES
Mortgage loans	281,384	307,908
Unsecured notes	2,675,644	2,580,108
Credit facility	420,000	259,000
Accounts payable	76,599	51,382
Accrued interest	38,954	26,154
Dividend and distributions payable	71,378	71,787
Other liabilities	204,031	243,806
Liabilities held for sale	25,416	0
Total liabilities	3,793,406	3,540,145
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2016 and December 31, 2015	7,537	7,537
EQUITY
General partner’s equity - 146,981,465 and 147,577,984 common units outstanding as of September 30, 2016 and December 31, 2015, respectively	2,866,810	2,952,928
Limited partners' equity	51,250	53,100
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	3,919	3,919
Total owners' equity	2,921,979	3,009,947
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,722,922	$ 6,557,629

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Deferred financing and leasing costs, accumulated amortization	$ 153,022,000	$ 175,798,000
Limited Partners' common units outstanding	3,530,031	3,539,075
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	146,981,465	147,577,984
Common shares of beneficial interest, shares outstanding	146,981,465	147,577,984
Liberty Property Limited Partnership [Member]
Deferred financing and leasing costs, accumulated amortization	$ 153,022,000	$ 175,798,000
Limited Partners' common units outstanding	3,530,031	3,539,075
Common shares of beneficial interest, shares outstanding	146,981,465	147,577,984
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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
OPERATING REVENUE
Rental	$ 140,697,000	$ 145,009,000	$ 418,896,000	$ 440,962,000
Operating expense reimbursement	50,160,000	53,963,000	148,757,000	168,430,000
Total operating revenue	190,857,000	198,972,000	567,653,000	609,392,000
OPERATING EXPENSE
Rental property	26,496,000	31,454,000	79,752,000	98,973,000
Real estate taxes	25,968,000	25,953,000	76,490,000	78,579,000
General and administrative	16,151,000	15,573,000	52,770,000	51,428,000
Depreciation and amortization	46,920,000	55,718,000	154,543,000	171,347,000
Impairment - real estate assets	0	0	0	16,775,000
Total operating expenses	115,535,000	128,698,000	363,555,000	417,102,000
Operating income	75,322,000	70,274,000	204,098,000	192,290,000
OTHER INCOME (EXPENSE)
Interest and other income	3,153,000	4,959,000	12,743,000	17,911,000
Loss on debt extinguishment	(3,494,000)	0	(3,494,000)	0
Interest expense	(29,528,000)	(33,559,000)	(91,071,000)	(103,295,000)
Total other income (expense)	(29,869,000)	(28,600,000)	(81,822,000)	(85,384,000)
Income before gain on property dispositions, income taxes and equity in earnings (loss) of unconsolidated joint ventures	45,453,000	41,674,000	122,276,000	106,906,000
Gain on property dispositions	1,318,000	53,467,000	25,671,000	56,987,000
Income taxes	(80,000)	(599,000)	(1,633,000)	(2,613,000)
Equity in earnings (loss) of unconsolidated joint ventures	9,043,000	(847,000)	19,540,000	805,000
Income from continuing operations	55,734,000	93,695,000	165,854,000	162,085,000
Net income	55,734,000	93,695,000	165,854,000	162,085,000
Noncontrolling interest – operating partnership	(1,424,000)	(2,306,000)	(4,250,000)	(4,117,000)
Noncontrolling interest - consolidated joint ventures	(57,000)	(58,000)	(170,000)	(171,000)
Net income available to common shareholders	54,253,000	91,331,000	161,434,000	157,797,000
Comprehensive income attributable to common shareholders
Net income	55,734,000	93,695,000	165,854,000	162,085,000
Other comprehensive loss - foreign currency translation	(4,407,000)	(7,970,000)	(23,003,000)	(6,229,000)
Other comprehensive gain (loss) - derivative instruments	663,000	(1,220,000)	(1,132,000)	(1,539,000)
Other comprehensive loss	(3,744,000)	(9,190,000)	(24,135,000)	(7,768,000)
Total comprehensive income	51,990,000	84,505,000	141,719,000	154,317,000
Less: comprehensive income attributable to noncontrolling interest	(1,393,000)	(2,148,000)	(3,851,000)	(4,105,000)
Comprehensive income attributable to common shareholders	$ 50,597,000	$ 82,357,000	$ 137,868,000	$ 150,212,000
Weighted average number of common shares outstanding
Basic	146,215	148,582	146,121	148,594
Diluted	147,107	149,176	146,788	149,220
Amounts attributable to common shareholders
Net income available to common shareholders	$ 54,253,000	$ 91,331,000	$ 161,434,000	$ 157,797,000
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental	140,697,000	145,009,000	418,896,000	440,962,000
Operating expense reimbursement	50,160,000	53,963,000	148,757,000	168,430,000
Total operating revenue	190,857,000	198,972,000	567,653,000	609,392,000
OPERATING EXPENSE
Rental property	26,496,000	31,454,000	79,752,000	98,973,000
Real estate taxes	25,968,000	25,953,000	76,490,000	78,579,000
General and administrative	16,151,000	15,573,000	52,770,000	51,428,000
Depreciation and amortization	46,920,000	55,718,000	154,543,000	171,347,000
Impairment - real estate assets			0	16,775,000
Total operating expenses	115,535,000	128,698,000	363,555,000	417,102,000
Operating income	75,322,000	70,274,000	204,098,000	192,290,000
OTHER INCOME (EXPENSE)
Interest and other income	3,153,000	4,959,000	12,743,000	17,911,000
Loss on debt extinguishment	(3,494,000)	0	(3,494,000)	0
Interest expense	(29,528,000)	(33,559,000)	(91,071,000)	(103,295,000)
Total other income (expense)	(29,869,000)	(28,600,000)	(81,822,000)	(85,384,000)
Income before gain on property dispositions, income taxes and equity in earnings (loss) of unconsolidated joint ventures	45,453,000	41,674,000	122,276,000	106,906,000
Gain on property dispositions	1,318,000	53,467,000	25,671,000	56,987,000
Income taxes	(80,000)	(599,000)	(1,633,000)	(2,613,000)
Equity in earnings (loss) of unconsolidated joint ventures	9,043,000	(847,000)	19,540,000	805,000
Net income	55,734,000	93,695,000	165,854,000	162,085,000
Noncontrolling interest - consolidated joint ventures	(57,000)	(58,000)	(170,000)	(171,000)
Preferred unit distributions	(118,000)	(118,000)	(354,000)	(354,000)
Net income available to common shareholders	55,559,000	93,519,000	165,330,000	161,560,000
Comprehensive income attributable to common shareholders
Net income	55,734,000	93,695,000	165,854,000	162,085,000
Other comprehensive loss - foreign currency translation	(4,407,000)	(7,970,000)	(23,003,000)	(6,229,000)
Other comprehensive gain (loss) - derivative instruments	663,000	(1,220,000)	(1,132,000)	(1,539,000)
Other comprehensive loss	(3,744,000)	(9,190,000)	(24,135,000)	(7,768,000)
Total comprehensive income	$ 51,990,000	$ 84,505,000	$ 141,719,000	$ 154,317,000
Weighted average number of common shares outstanding
Basic	149,751	152,121	149,659	152,134
Diluted	150,643	152,715	150,326	152,760
Net income allocated to general partners	$ 54,253,000	$ 91,331,000	$ 161,434,000	$ 157,797,000
Net income allocated to limited partners	1,424,000	2,306,000	4,250,000	4,117,000
Amounts attributable to common shareholders
Income from continuing operations	55,677,000	93,637,000	165,684,000	161,914,000
Net income available to common shareholders	$ 55,559,000	$ 93,519,000	$ 165,330,000	$ 161,560,000
Common shares [Member]
Basic:
Income per common share - basic	$ 0.37	$ 0.61	$ 1.10	$ 1.06
Diluted:
Income per common share - diluted	0.37	0.61	1.10	1.06
Distributions per common share or unit	0.475	0.475	1.425	1.425
Common Units [Member] | Liberty Property Limited Partnership [Member]
Basic:
Income per common share - basic	0.37	0.61	1.10	1.06
Diluted:
Income per common share - diluted	0.37	0.61	1.10	1.06
Distributions per common share or unit	$ 0.475	$ 0.475	$ 1.425	$ 1.425

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Accumulated Distributions in Excess of Net Income [Member]	Parent [Member]	Noncontrolling interest operating partnership Common [Member]	Noncontrolling interest-consolidated joint ventures [Member]	Liberty Property Limited Partnership [Member]	Liberty Property Limited Partnership [Member]General Partner [Member]	Liberty Property Limited Partnership [Member]Limited Partner [Member]	Liberty Property Limited Partnership [Member]Noncontrolling interest-consolidated joint ventures [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss - foreign currency translation	$ (6,229,000)								$ (6,229,000)
Other comprehensive loss - derivative instruments	(1,539,000)								(1,539,000)
Beginning Balance at Dec. 31, 2015	3,009,947,000	$ 148,000	$ 3,669,627,000	$ (17,893,000)	$ (698,954,000)	$ 2,952,928,000	$ 53,100,000	$ 3,919,000	3,009,947,000	$ 2,952,928,000	$ 53,100,000	$ 3,919,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares	11,967,000	0	11,967,000	0	0	11,967,000	0	0
Net income	165,500,000	0	0	0	161,434,000	161,434,000	3,896,000	170,000	165,500,000	161,434,000	3,896,000	170,000
Contributions from partners									25,788,000	25,788,000
Distributions	(214,225,000)	0	0	0	(209,010,000)	(209,010,000)	(5,045,000)	(170,000)
Distributions to partners									(214,225,000)	(209,010,000)	(5,045,000)	(170,000)
Share/Unit repurchase	(40,896,000)	(1,000)	(40,895,000)	0	0	(40,896,000)	0	0	(40,896,000)	(40,896,000)
Share-based compensation	13,821,000	0	13,821,000	0	0	13,821,000	0	0
Other comprehensive loss - foreign currency translation	(23,003,000)	0	0	(22,460,000)	0	(22,460,000)	(543,000)	0	(23,003,000)	(22,460,000)	(543,000)
Other comprehensive loss - derivative instruments	(1,132,000)	0	0	(1,106,000)	0	(1,106,000)	(26,000)	0	(1,132,000)	(1,106,000)	(26,000)
Redemption of noncontrolling interests - common units	0	0	132,000	0	0	132,000	(132,000)	0	0	132,000	(132,000)
Ending Balance at Sep. 30, 2016	2,921,979,000	$ 147,000	$ 3,654,652,000	$ (41,459,000)	$ (746,530,000)	$ 2,866,810,000	$ 51,250,000	$ 3,919,000	2,921,979,000	$ 2,866,810,000	$ 51,250,000	$ 3,919,000
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2015	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, 2016	$ 7,537,000								$ 7,537,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
OPERATING ACTIVITIES
Net income	$ 165,854,000	$ 162,085,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	156,562,000	173,726,000
Amortization of deferred financing costs	3,068,000	3,249,000
Impairment - real estate assets	0	16,775,000
Loss on debt extinguishment	3,494,000	0
Equity in earnings of unconsolidated joint ventures	(19,540,000)	(805,000)
Distributions from unconsolidated joint ventures	0	2,490,000
Gain on property dispositions	(25,671,000)	(56,987,000)
Share-based compensation/Non-cash compensation	12,841,000	10,709,000
Other	(5,326,000)	(8,143,000)
Changes in operating assets and liabilities:
Restricted cash	4,059,000	4,914,000
Accounts receivable	(4,980,000)	1,023,000
Deferred rent receivable	(12,948,000)	(17,122,000)
Prepaid expenses and other assets	(22,172,000)	(20,182,000)
Accounts payable	21,343,000	8,312,000
Accrued interest	12,800,000	19,258,000
Other liabilities	(2,561,000)	371,000
Net cash provided by operating activities	286,823,000	299,673,000
INVESTING ACTIVITIES
Investment in properties - acquisitions	(9,278,000)	(100,756,000)
Investment in properties - other	(44,017,000)	(58,038,000)
Investments in and advances to unconsolidated joint ventures	(50,460,000)	(30,609,000)
Distributions from unconsolidated joint ventures	49,372,000	23,093,000
Net proceeds from disposition of properties/land	142,808,000	243,943,000
Investment in development in progress	(259,193,000)	(123,547,000)
Investment in land held for development	(70,809,000)	(101,934,000)
Payment of deferred leasing costs	(22,306,000)	(34,404,000)
Investing - Other	4,874,000	(6,366,000)
Net cash used in investing activities	(259,009,000)	(188,618,000)
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	11,967,000	38,195,000
Share repurchase	(40,896,000)	(65,463,000)
Proceeds from unsecured notes	396,648,000	398,576,000
Repayment of unsecured notes including prepayment premium	(303,673,000)	(300,000,000)
Repayments of mortgage loans	(25,260,000)	(112,970,000)
Proceeds from credit facility	466,300,000	919,700,000
Repayments on credit facility	(305,300,000)	(786,700,000)
Payment of deferred financing costs	(2,600,000)	(3,478,000)
Distribution paid on common shares	(209,428,000)	(212,402,000)
Distribution paid on units	(5,690,000)	(5,704,000)
Net cash used in financing activities	(17,932,000)	(130,246,000)
Net increase (decrease) in cash and cash equivalents	9,882,000	(19,191,000)
Decrease in cash and cash equivalents related to foreign currency translation	(2,945,000)	(1,503,000)
Cash and cash equivalents at beginning of period	35,353,000	69,346,000
Cash and cash equivalents at end of period	42,290,000	48,652,000
Liberty Property Limited Partnership [Member]
OPERATING ACTIVITIES
Net income	165,854,000	162,085,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	156,562,000	173,726,000
Amortization of deferred financing costs	3,068,000	3,249,000
Impairment - real estate assets	0	16,775,000
Loss on debt extinguishment	3,494,000	0
Equity in earnings of unconsolidated joint ventures	(19,540,000)	(805,000)
Distributions from unconsolidated joint ventures	0	2,490,000
Gain on property dispositions	(25,671,000)	(56,987,000)
Share-based compensation/Non-cash compensation	12,841,000	10,709,000
Other	(5,326,000)	(8,143,000)
Changes in operating assets and liabilities:
Restricted cash	4,059,000	4,914,000
Accounts receivable	(4,980,000)	1,023,000
Deferred rent receivable	(12,948,000)	(17,122,000)
Prepaid expenses and other assets	(22,172,000)	(20,182,000)
Accounts payable	21,343,000	8,312,000
Accrued interest	12,800,000	19,258,000
Other liabilities	(2,561,000)	371,000
Net cash provided by operating activities	286,823,000	299,673,000
INVESTING ACTIVITIES
Investment in properties - acquisitions	(9,278,000)	(100,756,000)
Investment in properties - other	(44,017,000)	(58,038,000)
Investments in and advances to unconsolidated joint ventures	(50,460,000)	(30,609,000)
Distributions from unconsolidated joint ventures	49,372,000	23,093,000
Net proceeds from disposition of properties/land	142,808,000	243,943,000
Investment in development in progress	(259,193,000)	(123,547,000)
Investment in land held for development	(70,809,000)	(101,934,000)
Payment of deferred leasing costs	(22,306,000)	(34,404,000)
Investing - Other	4,874,000	(6,366,000)
Net cash used in investing activities	(259,009,000)	(188,618,000)
FINANCING ACTIVITIES
Proceeds from unsecured notes	396,648,000	398,576,000
Repayment of unsecured notes including prepayment premium	(303,673,000)	(300,000,000)
Repayments of mortgage loans	(25,260,000)	(112,970,000)
Proceeds from credit facility	466,300,000	919,700,000
Repayments on credit facility	(305,300,000)	(786,700,000)
Payment of deferred financing costs	(2,600,000)	(3,478,000)
Capital contributions	11,967,000	38,195,000
Distributions to partners	(256,014,000)	(283,569,000)
Net cash used in financing activities	(17,932,000)	(130,246,000)
Net increase (decrease) in cash and cash equivalents	9,882,000	(19,191,000)
Decrease in cash and cash equivalents related to foreign currency translation	(2,945,000)	(1,503,000)
Cash and cash equivalents at beginning of period	35,353,000	69,346,000
Cash and cash equivalents at end of period	$ 42,290,000	$ 48,652,000

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2016
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, 2016 . 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. As of January 1, 2016 under the revised accounting standard Topic 810 (see Recently Issued Accounting Standards below), the Operating Partnership is a variable interest entity ("VIE") of the Trust as the limited partners do not have substantive kick-out or participating rights. The Trust is the primary beneficiary of the Operating Partnership as it has the power to direct the activities of the Operating Partnership and the rights to absorb 97.7% of the net income of the Operating Partnership. The Trust has no significant assets or liabilities other than its investment in the Operating Partnership. As the Operating Partnership is already consolidated in the balance sheets of the Trust, the identification of this entity as a VIE has no impact on the consolidated financial statements of the Trust. In addition, the Company holds a 20% interest in Liberty/Comcast 1701 JFK Boulevard, LP which was determined to be a VIE. The Company determined that it is not the primary beneficiary as the Company and its third party partner share control of the joint venture. The Company's maximum exposure to loss is equal to its equity investment in the joint venture which was $19.3 million and $20.5 million as of September 30, 2016 and December 31, 2015, respectively. 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, 2015 . 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. 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 and has not yet selected a transition method. 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. The Company adopted ASU 2015-02 beginning January 1, 2016. The adoption of ASU 2015-02 did not have a material impact on the Company's financial position and results of operations. In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"). ASU 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU 2016-02 is effective for the Company beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. The standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The Company is evaluating the impact ASU 2016-02 will have on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships ("ASU 2016-05"). ASU 2016-05 states that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under FASB Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. ASU 2016-05 is effective for the Company beginning January 1, 2017. Early adoption of ASU 2016-05 is permitted. The standard allows application on a prospective or modified retrospective basis. The Company does not believe that ASU 2016-05 will have a material impact on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 is designed to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for the Company beginning January 1, 2017. Early adoption of ASU 2016-09 is permitted. Certain amendments in the standard are to be applied retrospectively and certain amendments are to be applied prospectively. The Company is evaluating the impact ASU 2016-09 will have on its financial position and results of operations. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 is designed to clarify how entities should classify cash receipts and cash payments in the statement of cash flows. ASU 2016-15 is effective for the Company beginning January 1, 2018. Early adoption of ASU 2016-15 is permitted. The standard requires retrospective application unless it is impracticable to do so. The Company is evaluating the impact ASU 2016-15 will have on its statement of cash flows.

Income per Common Share of the

Income per Common Share of the Trust	9 Months Ended
	Sep. 30, 2016
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, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 54,253 146,215 $ 0.37 $ 91,331 148,582 $ 0.61 Dilutive shares for long-term compensation plans — 892 — 594 Net income available to common shareholders - diluted $ 54,253 147,107 $ 0.37 $ 91,331 149,176 $ 0.61 For the Nine Months Ended For the Nine Months Ended September 30, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 161,434 146,121 $ 1.10 $ 157,797 148,594 $ 1.06 Dilutive shares for long-term compensation plans — 667 — 626 Net income available to common shareholders - diluted $ 161,434 146,788 $ 1.10 $ 157,797 149,220 $ 1.06 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, 2016 was 160,000 and 762,000 , respectively, as compared to 2,260,000 and 1,528,000 , respectively, for the same periods in 2015 . During the three and nine months ended September 30, 2016 , 241,000 and 353,000 common shares, respectively, were issued upon the exercise of options. During the year ended December 31, 2015 , 65,000 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 may 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 nine months ended September 30, 2016, the Company purchased an aggregate of 1.4 million common shares for $40.9 million at an average price of $29.28 per share as part of the share repurchase plan. There were no such purchases during the three months ended September 30, 2016 .

Income per Common Unit of the O

Income per Common Unit of the Operating Partnership	9 Months Ended
	Sep. 30, 2016
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, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 54,253 146,215 $ 0.37 $ 91,331 148,582 $ 0.61 Dilutive shares for long-term compensation plans — 892 — 594 Net income available to common shareholders - diluted $ 54,253 147,107 $ 0.37 $ 91,331 149,176 $ 0.61 For the Nine Months Ended For the Nine Months Ended September 30, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 161,434 146,121 $ 1.10 $ 157,797 148,594 $ 1.06 Dilutive shares for long-term compensation plans — 667 — 626 Net income available to common shareholders - diluted $ 161,434 146,788 $ 1.10 $ 157,797 149,220 $ 1.06 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, 2016 was 160,000 and 762,000 , respectively, as compared to 2,260,000 and 1,528,000 , respectively, for the same periods in 2015 . During the three and nine months ended September 30, 2016 , 241,000 and 353,000 common shares, respectively, were issued upon the exercise of options. During the year ended December 31, 2015 , 65,000 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 may 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 nine months ended September 30, 2016, the Company purchased an aggregate of 1.4 million common shares for $40.9 million at an average price of $29.28 per share as part of the share repurchase plan. There were no such purchases during the three months ended September 30, 2016 .
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, 2016 September 30, 2015 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income - net of noncontrolling interest - consolidated joint ventures $ 55,677 $ 93,637 Less: Preferred unit distributions (118 ) (118 ) Income available to common unitholders - basic $ 55,559 149,751 $ 0.37 $ 93,519 152,121 $ 0.61 Dilutive units for long-term compensation plans — 892 — 594 Income available to common unitholders - diluted $ 55,559 150,643 $ 0.37 $ 93,519 152,715 $ 0.61 For the Nine Months Ended For the Nine Months Ended September 30, 2016 September 30, 2015 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income - net of noncontrolling interest - consolidated joint ventures $ 165,684 $ 161,914 Less: Preferred unit distributions (354 ) (354 ) Income available to common unitholders - basic 165,330 149,659 $ 1.10 161,560 152,134 $ 1.06 Dilutive units for long-term compensation plans — 667 — 626 Income available to common unitholders - diluted $ 165,330 150,326 $ 1.10 $ 161,560 152,760 $ 1.06 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, 2016 was 160,000 and 762,000 , respectively, as compared to 2,260,000 and 1,528,000 , respectively, for the same periods in 2015 . During the three and nine months ended September 30, 2016 , 241,000 and 353,000 common units, respectively, were issued upon exercise of options. During the year ended December 31, 2015 , 65,000 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 may 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 nine months ended September 30, 2016, the Company purchased an aggregate of 1.4 million common shares for $40.9 million at an average price of $29.28 per share 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. There were no such purchases during the three months ended September 30, 2016 .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Loss The following table sets forth the components of Accumulated Other Comprehensive Loss (in thousands): As of and for the nine months ended September 30, 2016 2015 Foreign Currency Translation: Beginning balance $ (17,256 ) $ (5,823 ) Translation adjustment (23,003 ) (6,229 ) Ending balance (40,259 ) (12,052 ) Derivative Instruments: Beginning balance (865 ) (377 ) Unrealized loss (1,955 ) (2,592 ) Reclassification adjustment (1) 823 1,053 Ending balance (1,997 ) (1,916 ) Total accumulated other comprehensive loss (42,256 ) (13,968 ) Less: portion included in noncontrolling interest – operating partnership 797 131 Total accumulated other comprehensive loss included in shareholders' equity/owners' equity $ (41,459 ) $ (13,837 ) (1) Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate

Real Estate	9 Months Ended
	Sep. 30, 2016
Real Estate [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	Real Estate On October 3, 2016, the Company completed the sale of 108 properties totaling approximately 7.6 million square feet and 26.7 acres of land for $969 million . This sale did not represent a strategic shift for the Company. However, the sale does represent an individually significant disposition. The operating results for these properties and land are included in continued operations for all periods presented. Net income and net income available to common shareholders for these properties for the three and nine months ended 2016 and 2015, respectively, are as follows (in thousands): Three Months Nine Months Ended September 30, Ended September 30, 2016 2015 2016 2015 Net income $ 20,524 $ 14,595 $ 48,182 $ 45,126 Net income available to common shareholders $ 20,041 $ 14,252 $ 47,050 $ 44,079 As of September 30, 2016 these assets and liabilities were considered held for sale. These assets and liabilities consist of the following: Assets held for sale Land and land improvements $ 202,641 Building and improvements 834,286 Less accumulated depreciation (319,495 ) Operating real estate 717,432 Land held for development 15,524 Accounts receivable, net 1,358 Deferred rent receivable, net 22,140 Deferred financing and leasing costs, net 23,493 Prepaid expenses and other assets 3,595 Total assets held for sale $ 783,542 Liabilities held for sale Accounts payable $ 8,650 Other liabilities 16,766 Total liabilities held for sale $ 25,416 As of September 30, 2016, the Company also classified a parcel of land held for development with a carrying value of $2.7 million as assets held for sale. The Company's properties classified as held for sale by reportable segment as of September 30, 2016 are as follows: Properties Held for Sale Acres of Land Square Feet (000s) Minnesota 19 — 1,489 Florida 45 13.2 2,935 Southeastern PA 30 — 2,076 Other 14 18.1 1,079 Total 108 31.3 7,579 During the nine months ended September 30, 2016 , the Company acquired one operating property for a purchase price of $8.0 million . This property, comprising 73,000 square feet of leaseable space, is located in the Company's Chicago/Milwaukee reportable segment. The Company's sales by reportable segment for the three and nine months ended September 30, 2016 are as follows: Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Properties Sold Square Feet (000s) Gross Proceeds (000s) Properties Sold Square Feet (000s) Gross Proceeds (000s) Minnesota — — $ — 1 92 $ 9,200 Florida — — — 6 574 111,828 (1 ) Other 1 80 4,391 3 461 26,491 Total 1 80 $ 4,391 10 1,127 $ 147,519 (1) Includes gross proceeds from the sale of 3.5 acres of land.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2016
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. During the nine months ended September 30, 2016, the Company realigned its reportable segments as follows: • Carolinas/Richmond; • Chicago/Milwaukee; • Florida; • Houston; • Lehigh/Central PA; • Minnesota; • Philadelphia; • Southeastern PA; and • United Kingdom. Certain other segments are aggregated into an "Other" category which includes the reportable segments: Arizona; Atlanta; Cincinnati/Columbus/Indianapolis; Dallas; DC Metro; New Jersey; Northern Virginia; Southern California; and other. Comparative prior periods have been restated to reflect current segment disclosures. 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): Three Months Nine Months Ended September 30, Ended September 30, 2016 2015 2016 2015 Operating revenue Carolinas/Richmond $ 17,292 $ 15,723 $ 49,226 $ 56,271 Chicago/Milwaukee 11,384 8,872 31,896 27,596 Florida 28,115 32,072 85,230 94,430 Houston 14,870 12,981 43,840 38,455 Lehigh/Central PA 34,157 33,746 102,182 100,144 Minnesota 12,033 11,751 34,952 36,699 Philadelphia 10,513 10,552 31,253 30,422 Southeastern PA 24,563 36,718 74,789 114,430 United Kingdom 3,275 3,776 10,352 11,466 Other 34,831 32,801 104,274 99,636 Segment-level operating revenue 191,033 198,992 567,994 609,549 Reconciliation to total operating revenues Other (176 ) (20 ) (341 ) (157 ) Total operating revenue $ 190,857 $ 198,972 $ 567,653 $ 609,392 Net operating income Carolinas/Richmond $ 12,198 $ 10,809 $ 34,257 $ 37,017 Chicago/Milwaukee 7,103 5,792 20,917 18,660 Florida 18,340 19,301 53,129 57,861 Houston 7,989 7,829 24,858 22,739 Lehigh/Central PA 24,982 24,289 73,939 70,907 Minnesota 5,416 4,461 14,844 15,595 Philadelphia 7,725 7,898 23,064 22,230 Southeastern PA 16,244 20,887 44,544 63,301 United Kingdom 2,031 2,619 6,871 7,917 Other 22,643 21,750 68,422 66,138 Segment-level net operating income 124,671 125,635 364,845 382,365 Reconciliation to net income Interest expense (29,528 ) (33,559 ) (91,071 ) (103,295 ) Loss on debt extinguishment (3,494 ) — (3,494 ) — Depreciation/amortization expense (1) (34,896 ) (40,870 ) (113,855 ) (126,162 ) Impairment - real estate assets — — — (16,775 ) Gain on property dispositions 1,318 53,467 25,671 56,987 Equity in earnings (loss) of unconsolidated joint ventures 9,043 (847 ) 19,540 805 General and administrative expense (1) (10,595 ) (9,456 ) (34,209 ) (33,043 ) Income taxes (1) 17 (526 ) (1,203 ) (2,283 ) Other (802 ) (149 ) (370 ) 3,486 Net income $ 55,734 $ 93,695 $ 165,854 $ 162,085 (1) Excludes costs which are included in determining segment-level net operating income. The Company's total assets by reportable segment as of September 30, 2016 and December 31, 2015 is as follows (in thousands): September 30, 2016 December 31, 2015 Carolinas/Richmond $ 493,798 $ 467,098 Chicago/Milwaukee 433,679 429,390 Florida 796,806 874,352 Houston 530,388 522,285 Lehigh/Central PA 1,293,980 1,157,468 Minnesota 346,797 346,840 Philadelphia 517,956 444,889 Southeastern PA 449,288 448,523 United Kingdom 186,975 215,850 Other 1,601,797 1,586,481 Segment-level total assets 6,651,464 6,493,176 Corporate Other 71,458 64,453 Total assets $ 6,722,922 $ 6,557,629

Accounting for the Impairment o

Accounting for the Impairment or Disposal of Long-Lived Assets	9 Months Ended
	Sep. 30, 2016
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Asset Impairment Charges [Text Block]	Accounting for the Impairment or Disposal of Long-Lived Assets 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 and nine months ended September 30, 2016. During the three months ended September 30, 2015, the Company did not recognize any impairments. During the nine months ended September 30, 2015, the Company recognized $16.8 million in impairments, $13.4 million of which related to the Company's Carolinas/Richmond reportable segment, $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 DC Metro reportable segment. The properties included in the Carolinas/Richmond reportable segment were subsequently sold. 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 in ASC 820. These measurements have occurred throughout the respective periods as circumstances arise, and the resulting estimates of fair value are not necessarily reflective of measurements at the period’s end. 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, 2016 . In addition, the Company applied reasonable estimates and judgments in determining the level of impairments recognized. Should external or internal circumstances change requiring the need to shorten the holding periods or adjust the estimated future cash flows of the Company’s assets, the Company could be required to record impairment charges in the future.

Noncontrolling Interests of the

Noncontrolling Interests of the Trust	9 Months Ended
	Sep. 30, 2016
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 of the Operating Partnership not held by the Trust outstanding as of September 30, 2016 have the same economic characteristics as common shares of the Trust. The 3.5 million outstanding common units of the Operating Partnership 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 with unregistered common shares of the Trust. The market value of the 3.5 million outstanding common units based on the closing price of the common shares of the Trust at September 30, 2016 was $ 142.4 million .

Limited Partners' Equity of the

Limited Partners' Equity of the Operating Partnership	9 Months Ended
	Sep. 30, 2016
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 of the Operating Partnership not held by the Trust outstanding as of September 30, 2016 have the same economic characteristics as common shares of the Trust. The 3.5 million outstanding common units of the Operating Partnership 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 with unregistered common shares of the Trust. The market value of the 3.5 million outstanding common units based on the closing price of the common shares of the Trust at September 30, 2016 was $ 142.4 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 3.5 million outstanding common units as of September 30, 2016 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 with unregistered common shares of the Trust. The market value of the 3.5 million outstanding common units at September 30, 2016 based on the closing price of the common shares of the Trust at September 30, 2016 was $ 142.4 million .

Noncontrolling Interest - Opera

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units	9 Months Ended
	Sep. 30, 2016
Temporary Equity [Line Items]
Stockholders' Equity Note Disclosure [Text Block]	Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units As of September 30, 2016 , 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, 2016
Indebtedness [Abstract]
Long-term Debt [Text Block]	Indebtedness In September 2016, the Company issued $400 million of 3.25% senior unsecured notes due 2026. The Company used a substantial portion of the net proceeds from these notes to prepay its 5.5% Senior Notes due December 2016 in the amount of $300 million . This prepayment resulted in a $3.8 million loss on debt extinguishment.

Disclosure of Fair Value of Fin

Disclosure of Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2016
Debt Instrument, Fair Value Disclosure [Abstract]
Disclosure of Fair Value of Financial Instruments	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, 2016 and December 31, 2015 . 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 14 - Derivative Instruments. The Company used a discounted cash flow model to determine the estimated fair value of its debt as of September 30, 2016 and December 31, 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, 2015 and September 30, 2016 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2015 $ 307,908 $ 306,334 $ 2,580,108 $ 2,616,395 As of September 30, 2016 $ 281,384 $ 298,146 $ 2,675,644 $ 2,857,240

Unconsolidated Joint Ventures

Unconsolidated Joint Ventures	9 Months Ended
	Sep. 30, 2016
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 months ended September 30, 2016, Liberty Washington LP (a joint venture in which the Company holds a 25% interest) sold nine properties located in Northern Virginia containing 593,000 square feet and 6.0 acres of land for $106.7 million . During the nine months ended September 30, 2016, the joint venture sold 12 properties located in Northern Virginia containing 1.2 million square feet and 6.0 acres of land for $187.2 million . During the nine months ended September 30, 2016, due to adverse conditions in the Northern Virginia office market, six properties containing 698,000 square feet were transferred to mortgage lenders in satisfaction of an aggregate of $112.5 million in nonrecourse mortgage loans that were secured by the properties. The book values of these properties had been written down to fair value in prior periods. Because these loans were nonrecourse, the Company believes that the transfers described above will not have an ongoing effect on its operating results or financial condition. The Company's share of gain from property dispositions and extinguishment of debt is included in equity in earnings (loss) of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. During the nine months ended September 30, 2016, the Company's share of gain from extinguishment of debt was $4.2 million . There was no such gain during the three months ended September 30, 2016. The Company's share of gain on property dispositions for the three and nine months ended September 30, 2016 was $4.0 million and $6.0 million , respectively. Liberty Illinois, LP During the three months ended September 30, 2016, Liberty Illinois, LP (a joint venture in which the Company holds a 25% interest) sold four properties containing 636,000 square feet for $32.5 million . The Company's share of gain on property dispositions was $1.0 million . There were no other sales by this joint venture during the nine months ended September 30, 2016. Cambridge Medipark Ltd During the three and nine months ended September 30, 2016 and 2015, Cambridge Medipark, Ltd (a joint venture in which the Company holds a 50% interest) recognized gains on the sale of land leasehold interests. The Company's share of these gains was $3.3 million and $3.5 million for the three and nine months ended September 30, 2016, respectively, and $89,000 and $4.8 million , respectively, for the same periods in 2015.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2016
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. The Company's interest rate risk management objectives are to limit generally the impact of interest rate changes on earnings and cash flows and to lower the Company's overall borrowing costs. To achieve these objectives, from time to time, the Company enters 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. The Company generally does not hold or issue these derivative contracts for trading or speculative purposes. The interest rate on all of the Company's 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 (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 $99.5 million and $101.4 million at September 30, 2016 and December 31, 2015 , 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, 2016 and 2015 (in thousands): Three Months Ended Nine Months Ended September 30, 2016 September 30, 2015 September 30, 2016 September 30, 2015 Amount of gain (loss) related to the effective portion recognized in other comprehensive loss $ 415 $ (1,570 ) $ (1,928 ) $ (2,592 ) Amount of loss related to the effective portion subsequently reclassified to interest expense $ (264 ) $ (51 ) $ (823 ) $ (113 ) Amount of gain (loss) related to the ineffective portion recognized in interest expense $ 7 $ (350 ) $ (71 ) $ (1,053 ) The fair value of the Swaps in the amounts of $6.9 million and $7.1 million as of September 30, 2016 and December 31, 2015 , respectively, is included in other liabilities in the accompanying consolidated balance sheets. The Company estimates that $0.8 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 $7.0 million as of September 30, 2016 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
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, 2016 , were as follows (in thousands): Year Amount 2016 (remaining) $ 294 2017 1,429 2018 1,685 2019 1,685 2020 1,685 2021 and thereafter 36,253 Total $ 43,031 Operating ground lease expense for the three and nine months ended September 30, 2016 was $241,000 and $734,000 , respectively, as compared to $224,000 and $536,000 , respectively, for the same periods in 2015 . 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, 2016 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, 2016 , the Company had letter of credit obligations of $7.5 million . As of September 30, 2016 , the Company had 25 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 $606.2 million . At September 30, 2016 , development in progress totaled $427.7 million . In addition, as of September 30, 2016 , the Company had invested $11.3 million in deferred leasing costs related to these development buildings. Also, as of September 30, 2016 , the Company had signed an agreement, subject to the satisfaction of certain conditions, to develop an office building with a cost of approximately $96 million on land to be owned by the future occupant of the building and with funds to be advanced by the future occupant, and to guarantee the timely lien-free completion of construction of the building and the payment, subject to certain exceptions, of any cost overruns in the development of the building, all in consideration for a development fee payable to the Company. As of September 30, 2016 , the Company was committed to $38.4 million in improvements on certain buildings and land parcels. As of September 30, 2016 , the Company was committed to $29.4 million in future land purchases. As of September 30, 2016 , the Company was obligated to pay for tenant improvements not yet completed for a maximum of $30.8 million . As of September 30, 2016 , the Company was committed to fund up to $4.0 million for tenant improvements and leasing commissions under a loan to the buyer of certain of the Company's properties. Unconsolidated joint ventures in which the Company holds an interest have engaged the Company as the developer of its development properties pursuant to development agreements. The Company agrees, in consideration for a development fee, to be responsible for all aspects of the development of the properties and to guarantee the timely lien-free completion of construction of the properties and the payment, subject to certain exceptions, of any cost overruns incurred in the development of the properties. The Company is currently developing three buildings for its unconsolidated joint ventures which represent an anticipated aggregate investment by the joint ventures of $958.0 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, 2016
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, 2016 and 2015 (amounts in thousands): 2016 2015 Write-off of fully depreciated/amortized property and deferred costs $ 26,349 $ 44,216 Write-off of depreciated/amortized property and deferred costs due to sale/demolition $ 34,513 $ 95,277 Write-off of costs related to early debt extinguishment $ 109 $ — Redemption of noncontrolling interests - common units $ 132 $ 224 Unrealized loss on cash flow hedge $ (1,132 ) $ (1,539 ) Changes in accrued development capital expenditures $ (7,522 ) $ 5,023 Capitalized equity-based compensation in development in progress $ 980 $ — 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.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2016
Subsequent Event [Line Items]
Subsequent Events [Text Block]	Subsequent Events On October 3, 2016, the Company completed the sale of 108 properties totaling approximately 7.6 million square feet and 26.7 acres of land for $969 million . See Note 5: Real Estate for further details on this sale. The Company gave notice on October 5, 2016 of its intention to redeem on November 4, 2016 its 6.625% senior notes due October 2017 in the amount of $296.5 million and its 7.5% medium term notes due January 2018 in the amount of $100.0 million . The Company currently expects to incur debt extinguishment losses of approximately $23.3 million in the fourth quarter of 2016 as a result of these prepayments.

Organization and Basis of Pre24

Organization and Basis of Presentation (Policy)	9 Months Ended
	Sep. 30, 2016
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 and has not yet selected a transition method. 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. The Company adopted ASU 2015-02 beginning January 1, 2016. The adoption of ASU 2015-02 did not have a material impact on the Company's financial position and results of operations. In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"). ASU 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU 2016-02 is effective for the Company beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. The standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The Company is evaluating the impact ASU 2016-02 will have on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships ("ASU 2016-05"). ASU 2016-05 states that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under FASB Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. ASU 2016-05 is effective for the Company beginning January 1, 2017. Early adoption of ASU 2016-05 is permitted. The standard allows application on a prospective or modified retrospective basis. The Company does not believe that ASU 2016-05 will have a material impact on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 is designed to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for the Company beginning January 1, 2017. Early adoption of ASU 2016-09 is permitted. Certain amendments in the standard are to be applied retrospectively and certain amendments are to be applied prospectively. The Company is evaluating the impact ASU 2016-09 will have on its financial position and results of operations. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 is designed to clarify how entities should classify cash receipts and cash payments in the statement of cash flows. ASU 2016-15 is effective for the Company beginning January 1, 2018. Early adoption of ASU 2016-15 is permitted. The standard requires retrospective application unless it is impracticable to do so. The Company is evaluating the impact ASU 2016-15 will have on its statement of cash flows.

Income per Common Share of th25

Income per Common Share of the Trust (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 54,253 146,215 $ 0.37 $ 91,331 148,582 $ 0.61 Dilutive shares for long-term compensation plans — 892 — 594 Net income available to common shareholders - diluted $ 54,253 147,107 $ 0.37 $ 91,331 149,176 $ 0.61 For the Nine Months Ended For the Nine Months Ended September 30, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 161,434 146,121 $ 1.10 $ 157,797 148,594 $ 1.06 Dilutive shares for long-term compensation plans — 667 — 626 Net income available to common shareholders - diluted $ 161,434 146,788 $ 1.10 $ 157,797 149,220 $ 1.06

Income per Common Unit of the26

Income per Common Unit of the Operating Partnership (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 54,253 146,215 $ 0.37 $ 91,331 148,582 $ 0.61 Dilutive shares for long-term compensation plans — 892 — 594 Net income available to common shareholders - diluted $ 54,253 147,107 $ 0.37 $ 91,331 149,176 $ 0.61 For the Nine Months Ended For the Nine Months Ended September 30, 2016 September 30, 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Net income available to common shareholders - basic $ 161,434 146,121 $ 1.10 $ 157,797 148,594 $ 1.06 Dilutive shares for long-term compensation plans — 667 — 626 Net income available to common shareholders - diluted $ 161,434 146,788 $ 1.10 $ 157,797 149,220 $ 1.06
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, 2016 September 30, 2015 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income - net of noncontrolling interest - consolidated joint ventures $ 55,677 $ 93,637 Less: Preferred unit distributions (118 ) (118 ) Income available to common unitholders - basic $ 55,559 149,751 $ 0.37 $ 93,519 152,121 $ 0.61 Dilutive units for long-term compensation plans — 892 — 594 Income available to common unitholders - diluted $ 55,559 150,643 $ 0.37 $ 93,519 152,715 $ 0.61 For the Nine Months Ended For the Nine Months Ended September 30, 2016 September 30, 2015 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income - net of noncontrolling interest - consolidated joint ventures $ 165,684 $ 161,914 Less: Preferred unit distributions (354 ) (354 ) Income available to common unitholders - basic 165,330 149,659 $ 1.10 161,560 152,134 $ 1.06 Dilutive units for long-term compensation plans — 667 — 626 Income available to common unitholders - diluted $ 165,330 150,326 $ 1.10 $ 161,560 152,760 $ 1.06

Accumulated Other Comprehensi27

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2016
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 Loss (in thousands): As of and for the nine months ended September 30, 2016 2015 Foreign Currency Translation: Beginning balance $ (17,256 ) $ (5,823 ) Translation adjustment (23,003 ) (6,229 ) Ending balance (40,259 ) (12,052 ) Derivative Instruments: Beginning balance (865 ) (377 ) Unrealized loss (1,955 ) (2,592 ) Reclassification adjustment (1) 823 1,053 Ending balance (1,997 ) (1,916 ) Total accumulated other comprehensive loss (42,256 ) (13,968 ) Less: portion included in noncontrolling interest – operating partnership 797 131 Total accumulated other comprehensive loss included in shareholders' equity/owners' equity $ (41,459 ) $ (13,837 ) (1) Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate (Tables)

Real Estate (Tables)	9 Months Ended
	Sep. 30, 2016
Real Estate [Abstract]
Disposal Groups, Including Discontinued Operations [Table Text Block]	Net income and net income available to common shareholders for these properties for the three and nine months ended 2016 and 2015, respectively, are as follows (in thousands): Three Months Nine Months Ended September 30, Ended September 30, 2016 2015 2016 2015 Net income $ 20,524 $ 14,595 $ 48,182 $ 45,126 Net income available to common shareholders $ 20,041 $ 14,252 $ 47,050 $ 44,079 As of September 30, 2016 these assets and liabilities were considered held for sale. These assets and liabilities consist of the following: Assets held for sale Land and land improvements $ 202,641 Building and improvements 834,286 Less accumulated depreciation (319,495 ) Operating real estate 717,432 Land held for development 15,524 Accounts receivable, net 1,358 Deferred rent receivable, net 22,140 Deferred financing and leasing costs, net 23,493 Prepaid expenses and other assets 3,595 Total assets held for sale $ 783,542 Liabilities held for sale Accounts payable $ 8,650 Other liabilities 16,766 Total liabilities held for sale $ 25,416
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]	The Company's properties classified as held for sale by reportable segment as of September 30, 2016 are as follows: Properties Held for Sale Acres of Land Square Feet (000s) Minnesota 19 — 1,489 Florida 45 13.2 2,935 Southeastern PA 30 — 2,076 Other 14 18.1 1,079 Total 108 31.3 7,579
Real Estate Properties Sold [Table Text Block]	The Company's sales by reportable segment for the three and nine months ended September 30, 2016 are as follows: Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Properties Sold Square Feet (000s) Gross Proceeds (000s) Properties Sold Square Feet (000s) Gross Proceeds (000s) Minnesota — — $ — 1 92 $ 9,200 Florida — — — 6 574 111,828 (1 ) Other 1 80 4,391 3 461 26,491 Total 1 80 $ 4,391 10 1,127 $ 147,519 (1) Includes gross proceeds from the sale of 3.5 acres of land.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
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): Three Months Nine Months Ended September 30, Ended September 30, 2016 2015 2016 2015 Operating revenue Carolinas/Richmond $ 17,292 $ 15,723 $ 49,226 $ 56,271 Chicago/Milwaukee 11,384 8,872 31,896 27,596 Florida 28,115 32,072 85,230 94,430 Houston 14,870 12,981 43,840 38,455 Lehigh/Central PA 34,157 33,746 102,182 100,144 Minnesota 12,033 11,751 34,952 36,699 Philadelphia 10,513 10,552 31,253 30,422 Southeastern PA 24,563 36,718 74,789 114,430 United Kingdom 3,275 3,776 10,352 11,466 Other 34,831 32,801 104,274 99,636 Segment-level operating revenue 191,033 198,992 567,994 609,549 Reconciliation to total operating revenues Other (176 ) (20 ) (341 ) (157 ) Total operating revenue $ 190,857 $ 198,972 $ 567,653 $ 609,392 Net operating income Carolinas/Richmond $ 12,198 $ 10,809 $ 34,257 $ 37,017 Chicago/Milwaukee 7,103 5,792 20,917 18,660 Florida 18,340 19,301 53,129 57,861 Houston 7,989 7,829 24,858 22,739 Lehigh/Central PA 24,982 24,289 73,939 70,907 Minnesota 5,416 4,461 14,844 15,595 Philadelphia 7,725 7,898 23,064 22,230 Southeastern PA 16,244 20,887 44,544 63,301 United Kingdom 2,031 2,619 6,871 7,917 Other 22,643 21,750 68,422 66,138 Segment-level net operating income 124,671 125,635 364,845 382,365 Reconciliation to net income Interest expense (29,528 ) (33,559 ) (91,071 ) (103,295 ) Loss on debt extinguishment (3,494 ) — (3,494 ) — Depreciation/amortization expense (1) (34,896 ) (40,870 ) (113,855 ) (126,162 ) Impairment - real estate assets — — — (16,775 ) Gain on property dispositions 1,318 53,467 25,671 56,987 Equity in earnings (loss) of unconsolidated joint ventures 9,043 (847 ) 19,540 805 General and administrative expense (1) (10,595 ) (9,456 ) (34,209 ) (33,043 ) Income taxes (1) 17 (526 ) (1,203 ) (2,283 ) Other (802 ) (149 ) (370 ) 3,486 Net income $ 55,734 $ 93,695 $ 165,854 $ 162,085 (1) Excludes costs which are included in determining segment-level net operating income.
Assets by Segment and Reconciliation to Consolidated[Table Text Block]	The Company's total assets by reportable segment as of September 30, 2016 and December 31, 2015 is as follows (in thousands): September 30, 2016 December 31, 2015 Carolinas/Richmond $ 493,798 $ 467,098 Chicago/Milwaukee 433,679 429,390 Florida 796,806 874,352 Houston 530,388 522,285 Lehigh/Central PA 1,293,980 1,157,468 Minnesota 346,797 346,840 Philadelphia 517,956 444,889 Southeastern PA 449,288 448,523 United Kingdom 186,975 215,850 Other 1,601,797 1,586,481 Segment-level total assets 6,651,464 6,493,176 Corporate Other 71,458 64,453 Total assets $ 6,722,922 $ 6,557,629

Noncontrolling Interest - Ope30

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Tables)	9 Months Ended
	Sep. 30, 2016
Temporary Equity [Line Items]
Schedule of Temporary Equity [Table Text Block]	As of September 30, 2016 , 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 F31

Disclosure of Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2015 and September 30, 2016 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2015 $ 307,908 $ 306,334 $ 2,580,108 $ 2,616,395 As of September 30, 2016 $ 281,384 $ 298,146 $ 2,675,644 $ 2,857,240

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 and 2015 (in thousands): Three Months Ended Nine Months Ended September 30, 2016 September 30, 2015 September 30, 2016 September 30, 2015 Amount of gain (loss) related to the effective portion recognized in other comprehensive loss $ 415 $ (1,570 ) $ (1,928 ) $ (2,592 ) Amount of loss related to the effective portion subsequently reclassified to interest expense $ (264 ) $ (51 ) $ (823 ) $ (113 ) Amount of gain (loss) related to the ineffective portion recognized in interest expense $ 7 $ (350 ) $ (71 ) $ (1,053 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 , were as follows (in thousands): Year Amount 2016 (remaining) $ 294 2017 1,429 2018 1,685 2019 1,685 2020 1,685 2021 and thereafter 36,253 Total $ 43,031

Supplemental Disclosure to St34

Supplemental Disclosure to Statements of Cash Flows (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 and 2015 (amounts in thousands): 2016 2015 Write-off of fully depreciated/amortized property and deferred costs $ 26,349 $ 44,216 Write-off of depreciated/amortized property and deferred costs due to sale/demolition $ 34,513 $ 95,277 Write-off of costs related to early debt extinguishment $ 109 $ — Redemption of noncontrolling interests - common units $ 132 $ 224 Unrealized loss on cash flow hedge $ (1,132 ) $ (1,539 ) Changes in accrued development capital expenditures $ (7,522 ) $ 5,023 Capitalized equity-based compensation in development in progress $ 980 $ —

Organization and Basis of Pre35

Organization and Basis of Presentation (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Ownership interest in operating partnership - Limited Partnership	97.70%
Liberty Comcast 1701 JFK Boulevard, LP [Member]
Variable Interest Entity [Line Items]
Equity Method Investment, Ownership Percentage	20.00%
Liberty Comcast 1701 JFK Boulevard, LP [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Other Investments [Member]
Variable Interest Entity [Line Items]
Equity investment in joint venture	$ 19.3	$ 20.5
Maximum exposure to loss	$ 19.3	$ 20.5

Income per Common Share of th36

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income (Numerator) [Abstract]
Net income available to common shareholders	$ 54,253	$ 91,331	$ 161,434	$ 157,797
Weighted Average Shares (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	146,215	148,582	146,121	148,594
Dilutive shares for long-term compensation plans	892	594	667	626
Weighted Average Number of Shares Outstanding, Diluted	147,107	149,176	146,788	149,220
Common shares [Member]
Earnings Per Share, Basic [Abstract]
Income per common share - basic	$ 0.37	$ 0.61	$ 1.10	$ 1.06
Earnings Per Share, Diluted [Abstract]
Income per common share - diluted	$ 0.37	$ 0.61	$ 1.10	$ 1.06

Income per Common Share of th37

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock Option [Member]
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Options Excluded from Computation of Earnings Per Share	160,000	2,260,000	762,000	1,528,000

Income per Common Share of th38

Income per Common Share of the Trust - Options Exercised (Details) - shares	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Stock Option [Member] | Common shares [Member]
Stock Option Exercises [Line Items]
Amount of Options Exercises in Period	241,000	353,000	65,000

Income per Common Share of th39

Income per Common Share of the Trust - Share Repurchase (Details) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016USD ($)shares	Sep. 30, 2016USD ($)$ / sharesshares
Class of Stock [Line Items]
Amount paid for repurchase of shares		$ 40,896
Common shares [Member] | 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Authorized amount of shares available to be repurchased under a share repurchase plan	$ 250,000	$ 250,000
Number of shares repurchased during period | shares	0	1.4
Amount paid for repurchase of shares		$ 40,900
Stock Acquired, Average Cost Per Share | $ / shares		$ 29.28

Income per Common Unit of the40

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income (Numerator) [Abstract]
Net income available to common shareholders	$ 54,253	$ 91,331	$ 161,434	$ 157,797
Weighted Average Units (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	146,215	148,582	146,121	148,594
Dilutive units for long-term compensation plans	892	594	667	626
Weighted Average Number of Shares Outstanding, Diluted	147,107	149,176	146,788	149,220
Liberty Property Limited Partnership [Member]
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$ 55,677	$ 93,637	$ 165,684	$ 161,914
Less: Preferred unit distributions	(118)	(118)	(354)	(354)
Net income available to common shareholders	$ 55,559	$ 93,519	$ 165,330	$ 161,560
Weighted Average Units (Denominator) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	149,751	152,121	149,659	152,134
Dilutive units for long-term compensation plans	892	594	667	626
Weighted Average Number of Shares Outstanding, Diluted	150,643	152,715	150,326	152,760
Liberty Property Limited Partnership [Member] | Common Units [Member]
Earnings Per Unit, Basic [Abstract]
Income per common share - basic	$ 0.37	$ 0.61	$ 1.10	$ 1.06
Earnings Per Unit, Diluted [Abstract]
Income per common share - diluted	$ 0.37	$ 0.61	$ 1.10	$ 1.06

Income per Common Unit of the41

Income per Common Unit of the Operating Partnership - Anti-dilutive Options (Details) - Stock Option [Member] - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Options Excluded from Computation of Earnings Per Share	160,000	2,260,000	762,000	1,528,000
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	160,000	2,260,000	762,000	1,528,000

Income per Common Unit of the42

Income per Common Unit of the Operations Partnership - Options Exercised (Details) - shares	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Liberty Property Limited Partnership [Member] | Stock Option [Member] | Common Units [Member]
Stock Option Exercises [Line Items]
Amount of Options Exercises in Period	241,000	353,000	65,000

Income per Common Unit of the43

Income per Common Unit of the Operating Partnership - Unit Repurchase (Details) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016USD ($)shares	Sep. 30, 2016USD ($)$ / sharesshares
Class of Stock [Line Items]
Amount paid for repurchase of units		$ 40,896
Common shares [Member] | 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Authorized amount of shares available to be repurchased under a share repurchase plan	$ 250,000	$ 250,000
Number of units repurchased during period | shares	0	1,400,000
Amount paid for repurchase of units		$ 40,900
Stock Acquired, Average Cost Per Share | $ / shares		$ 29.28
Liberty Property Limited Partnership [Member]
Class of Stock [Line Items]
Amount paid for repurchase of units		$ 40,896
Liberty Property Limited Partnership [Member] | Common Units [Member] | 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Authorized amount of shares available to be repurchased under a share repurchase plan	$ 250,000	$ 250,000
Number of units repurchased during period | shares	0	1,400,000
Amount paid for repurchase of units		$ 40,900
Liberty Property Limited Partnership [Member] | Common shares [Member] | 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Acquired, Average Cost Per Share | $ / shares		$ 29.28

Accumulated Other Comprehensi44

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		$ 3,009,947
Ending Balance		2,921,979
Total accumulated other comprehensive loss		3,009,947		$ 2,921,979	$ 3,009,947
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity				2,866,810	2,952,928
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		(17,256)	$ (5,823)
Unrealized loss		(23,003)	(6,229)
Ending Balance		(40,259)	(12,052)
Total accumulated other comprehensive loss		(17,256)	(5,823)	(40,259)	(17,256)	$ (12,052)
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		(865)	(377)
Unrealized loss		(1,955)	(2,592)
Reclassification adjustment	[1]	823	1,053
Ending Balance		(1,997)	(1,916)
Total accumulated other comprehensive loss		(865)	(377)	(1,997)	(865)	(1,916)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		(42,256)	(13,968)
Total accumulated other comprehensive loss		(42,256)	(13,968)	(42,256)		(13,968)
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		797	131
Total accumulated other comprehensive loss		797	$ 131	797		131
AOCI Attributable to Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(17,893)
Ending Balance		(41,459)
Total accumulated other comprehensive loss		$ (17,893)		(41,459)	$ (17,893)
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity				$ (41,459)		$ (13,837)
[1]	Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Assets Held for Sale (Details)

Assets Held for Sale (Details) $ in Thousands, ft² in Millions	Oct. 03, 2016USD ($)ft²abldg	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Buildings and Land				$ 142,808	$ 243,943
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Total assets held for sale		$ 786,272		786,272		$ 4,954
Total liabilities held for sale		25,416		25,416		$ 0
October 2016 Sale [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Net income		20,524	$ 14,595	48,182	45,126
Net income available to common shareholders		20,041	$ 14,252	47,050	$ 44,079
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Land and Land Improvements		202,641		202,641
Building and Building Improvements		834,286		834,286
Less accumulated depreciation		(319,495)		(319,495)
Operating real estate		717,432		717,432
Land held for development		15,524		15,524
Accounts receivable, net		1,358		1,358
Deferred rent receivable, net		22,140		22,140
Deferred financing and leasing costs, net		23,493		23,493
Prepaid expenses and other assets		3,595		3,595
Total assets held for sale		783,542		783,542
Accounts payable		8,650		8,650
Other liabilities		16,766		16,766
Total liabilities held for sale		25,416		25,416
2016 held for sale [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Land held for development		$ 2,700		$ 2,700
Subsequent Event [Member] | October 2016 Sale [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties | bldg	108
Area of Real Estate Property | ft²	7.6
Area of Land | a	26.7
Proceeds from Sale of Buildings and Land	$ 969,000

Assets Held for Sale by Segment

Assets Held for Sale by Segment (Details) - Operating Segments [Member] - 2016 held for sale [Member] - Disposal Group, Held-for-sale, Not Discontinued Operations [Member] ft² in Thousands	Sep. 30, 2016ft²abldg
Land and Land Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of Land | a	31.3
Building and Building Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties | bldg	108
Net Rentable Area | ft²	7,579
Minnesota [Member] | Land and Land Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of Land | a	0
Minnesota [Member] | Building and Building Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties | bldg	19
Net Rentable Area | ft²	1,489
Florida [Member] | Land and Land Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of Land | a	13.2
Florida [Member] | Building and Building Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties | bldg	45
Net Rentable Area | ft²	2,935
Southeastern PA [Member] | Land and Land Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of Land | a	0
Southeastern PA [Member] | Building and Building Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties | bldg	30
Net Rentable Area | ft²	2,076
Other Segments [Member] | Land and Land Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of Land | a	18.1
Other Segments [Member] | Building and Building Improvements [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Real Estate Properties | bldg	14
Net Rentable Area | ft²	1,079

Building Acquisitions and Dispo

Building Acquisitions and Dispositions (Details) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2016USD ($)ft²abldg	Sep. 30, 2016USD ($)ft²abldg	Sep. 30, 2015USD ($)
Property, Plant and Equipment [Line Items]
Proceeds from Sale of Buildings and Land			$ 142,808	$ 243,943
Disposal Group, Not Discontinued Operations [Member] | 2016 sales current quarter [Member] | Operating Segments [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		1	1
Net Rentable Area | ft²		80,000	80,000
Proceeds from Sale of Buildings and Land		$ 4,391
Disposal Group, Not Discontinued Operations [Member] | 2016 sales current quarter [Member] | Operating Segments [Member] | Minnesota [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		0	0
Net Rentable Area | ft²		0	0
Proceeds from Sale of Buildings and Land		$ 0
Disposal Group, Not Discontinued Operations [Member] | 2016 sales current quarter [Member] | Operating Segments [Member] | Florida [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		0	0
Net Rentable Area | ft²		0	0
Proceeds from Sale of Buildings and Land		$ 0
Disposal Group, Not Discontinued Operations [Member] | 2016 sales current quarter [Member] | Operating Segments [Member] | Other Segments [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		1	1
Net Rentable Area | ft²		80,000	80,000
Proceeds from Sale of Buildings and Land		$ 4,391
Disposal Group, Not Discontinued Operations [Member] | 2016 sales [Member] | Operating Segments [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		10	10
Net Rentable Area | ft²		1,127,000	1,127,000
Proceeds from Sale of Buildings and Land			$ 147,519
Disposal Group, Not Discontinued Operations [Member] | 2016 sales [Member] | Operating Segments [Member] | Minnesota [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		1	1
Net Rentable Area | ft²		92,000	92,000
Proceeds from Sale of Buildings and Land			$ 9,200
Disposal Group, Not Discontinued Operations [Member] | 2016 sales [Member] | Operating Segments [Member] | Florida [Member] | Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Area of Land | a		3.5	3.5
Disposal Group, Not Discontinued Operations [Member] | 2016 sales [Member] | Operating Segments [Member] | Florida [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		6	6
Net Rentable Area | ft²		574,000	574,000
Proceeds from Sale of Buildings and Land	[1]		$ 111,828
Disposal Group, Not Discontinued Operations [Member] | 2016 sales [Member] | Operating Segments [Member] | Other Segments [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		3	3
Net Rentable Area | ft²		461,000	461,000
Proceeds from Sale of Buildings and Land			$ 26,491
2016 acquisitions [Member] | Operating Segments [Member] | Chicago Milwaukee [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Number of Real Estate Properties | bldg		1	1
Payments to Acquire Commercial Real Estate			$ 8,000
Net Rentable Area | ft²		73,000	73,000
[1]	Includes gross proceeds from the sale of 3.5 acres of land.

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Operating revenue		$ 190,857,000	$ 198,972,000	$ 567,653,000	$ 609,392,000
Net operating income		75,322,000	70,274,000	204,098,000	192,290,000
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense		(29,528,000)	(33,559,000)	(91,071,000)	(103,295,000)
Loss on debt extinguishment		(3,494,000)	0	(3,494,000)	0
Depreciation and amortization expense				(156,562,000)	(173,726,000)
Impairment - real estate assets		0	0	0	(16,775,000)
Gain on property dispositions		1,318,000	53,467,000	25,671,000	56,987,000
Equity in earnings (loss) of unconsolidated joint ventures		9,043,000	(847,000)	19,540,000	805,000
General and administrative expense		(16,151,000)	(15,573,000)	(52,770,000)	(51,428,000)
Income taxes		(80,000)	(599,000)	(1,633,000)	(2,613,000)
Net income		55,734,000	93,695,000	165,854,000	162,085,000
Carolinas Richmond [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		191,033,000	198,992,000	567,994,000	609,549,000
Net operating income		124,671,000	125,635,000	364,845,000	382,365,000
Operating Segments [Member] | Carolinas Richmond [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		17,292,000	15,723,000	49,226,000	56,271,000
Net operating income		12,198,000	10,809,000	34,257,000	37,017,000
Operating Segments [Member] | Chicago Milwaukee [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		11,384,000	8,872,000	31,896,000	27,596,000
Net operating income		7,103,000	5,792,000	20,917,000	18,660,000
Operating Segments [Member] | Florida [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		28,115,000	32,072,000	85,230,000	94,430,000
Net operating income		18,340,000	19,301,000	53,129,000	57,861,000
Operating Segments [Member] | Houston [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		14,870,000	12,981,000	43,840,000	38,455,000
Net operating income		7,989,000	7,829,000	24,858,000	22,739,000
Operating Segments [Member] | Lehigh Central PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		34,157,000	33,746,000	102,182,000	100,144,000
Net operating income		24,982,000	24,289,000	73,939,000	70,907,000
Operating Segments [Member] | Minnesota [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		12,033,000	11,751,000	34,952,000	36,699,000
Net operating income		5,416,000	4,461,000	14,844,000	15,595,000
Operating Segments [Member] | Philadelphia [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		10,513,000	10,552,000	31,253,000	30,422,000
Net operating income		7,725,000	7,898,000	23,064,000	22,230,000
Operating Segments [Member] | Southeastern PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		24,563,000	36,718,000	74,789,000	114,430,000
Net operating income		16,244,000	20,887,000	44,544,000	63,301,000
Operating Segments [Member] | United Kingdom [Member] | UNITED KINGDOM
Segment Reporting Information [Line Items]
Operating revenue		3,275,000	3,776,000	10,352,000	11,466,000
Net operating income		2,031,000	2,619,000	6,871,000	7,917,000
Operating Segments [Member] | Other Segments [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating revenue		34,831,000	32,801,000	104,274,000	99,636,000
Net operating income		22,643,000	21,750,000	68,422,000	66,138,000
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenue		(176,000)	(20,000)	(341,000)	(157,000)
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense		(29,528,000)	(33,559,000)	(91,071,000)	(103,295,000)
Loss on debt extinguishment		(3,494,000)	0	(3,494,000)	0
Depreciation and amortization expense	[1]	(34,896,000)	(40,870,000)	(113,855,000)	(126,162,000)
Impairment - real estate assets		0	0	0	(16,775,000)
Gain on property dispositions		1,318,000	53,467,000	25,671,000	56,987,000
Equity in earnings (loss) of unconsolidated joint ventures		9,043,000	(847,000)	19,540,000	805,000
General and administrative expense	[1]	(10,595,000)	(9,456,000)	(34,209,000)	(33,043,000)
Income taxes	[1]	17,000	(526,000)	(1,203,000)	(2,283,000)
Other		$ (802,000)	$ (149,000)	$ (370,000)	$ 3,486,000
[1]	Excludes costs which are included in determining segment-level net operating income.

Segment Information Total Asset

Segment Information Total Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Assets	$ 6,722,922	$ 6,557,629
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	6,651,464	6,493,176
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Assets	71,458	64,453
North America [Member] | Operating Segments [Member] | Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Assets	493,798	467,098
North America [Member] | Operating Segments [Member] | Chicago Milwaukee [Member]
Segment Reporting Information [Line Items]
Assets	433,679	429,390
North America [Member] | Operating Segments [Member] | Florida [Member]
Segment Reporting Information [Line Items]
Assets	796,806	874,352
North America [Member] | Operating Segments [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Assets	530,388	522,285
North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Assets	1,293,980	1,157,468
North America [Member] | Operating Segments [Member] | Minnesota [Member]
Segment Reporting Information [Line Items]
Assets	346,797	346,840
North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Assets	517,956	444,889
North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Assets	449,288	448,523
North America [Member] | Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Assets	1,601,797	1,586,481
UNITED KINGDOM | Operating Segments [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Assets	$ 186,975	$ 215,850

Accounting for the Impairment50

Accounting for the Impairment or Disposal of Long-Lived Assets Asset Impairment (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Impairment - real estate assets	$ 0	$ 0	$ 0	$ 16,775,000
Carolinas Richmond [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
DC Metro [Member]
Property, Plant and Equipment [Line Items]
Impairment - real estate assets				$ 1,000,000

Noncontrolling Interests of t51

Noncontrolling Interests of the Trust- Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Redeemable Noncontrolling Interest [Line Items]
Limited Partners' common units outstanding	3,530,031	3,539,075
Market value of common units based on closing price	$ 142.4
Liberty Property Limited Partnership [Member]
Redeemable Noncontrolling Interest [Line Items]
Limited Partners' common units outstanding	3,530,031	3,539,075

Limited Partners' Equity of t52

Limited Partners' Equity of the Operating Partnership - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Limited Partners' Capital Account [Line Items]
Limited Partners' common units outstanding	3,530,031	3,539,075
Liberty Property Limited Partnership [Member]
Limited Partners' Capital Account [Line Items]
Limited Partners' common units outstanding	3,530,031	3,539,075
market value of the outstanding common units	$ 142.4

Noncontrolling Interest - Ope53

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Temporary Equity [Line Items]
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of September 30, 2016 and December 31, 2015	$ 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, 2016 and December 31, 2015	$ 7,537
Units	301,483	301,483
Liquidation Preference	$ 25
Dividend Rate	6.25%

Indebtedness (Details)

Indebtedness (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 01, 2016
Debt Instrument [Line Items]
Loss on debt extinguishment	$ 3,494	$ 0	$ 3,494	$ 0
Senior Notes [Member] | 5.5% Senior Note [Member]
Debt Instrument [Line Items]
Interest rate on notes					5.50%
Debt amount repurchased					$ 300,000
Loss on debt extinguishment	$ 3,800
Senior Notes [Member] | 3.25% Senior Notes [Member]
Debt Instrument [Line Items]
Debt amount issued					$ 400,000
Interest rate on notes					3.25%

Disclosure of Fair Value of F55

Disclosure of Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage loans	$ 281,384	$ 307,908
Unsecured Debt	2,675,644	2,580,108
Unsecured Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Long-term Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt	2,857,240	2,616,395
Mortgage Loans | Fair Value, Inputs, Level 3 [Member] | Long-term Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt	$ 298,146	$ 306,334

Unconsolidated Joint Ventures (

Unconsolidated Joint Ventures (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)ft²abldg	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)ft²abldg	Sep. 30, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Gain on extinguishment of debt	$ (3,494,000)	$ 0	$ (3,494,000)	$ 0
Gain on sale of properties			$ 25,671,000	56,987,000
Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%
Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Sale [Member] | Joint venture, 2016 sales [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Net Rentable Area | ft²	1,200,000		1,200,000
Number of Real Estate Properties | bldg	12		12
Proceeds from Sale of Property			$ 187,200,000
Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Sale [Member] | Joint venture, 2016 sales [Member] | Land and Land Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Area of Land | a	6		6
Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Sale [Member] | Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Net Rentable Area | ft²	593,000		593,000
Number of Real Estate Properties | bldg	9		9
Proceeds from Sale of Property	$ 106,700,000
Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Sale [Member] | Joint venture, 2016 sales current quarter [Member] | Land and Land Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Area of Land | a	6		6
Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Means Other than Sale [Member] | Joint venture, 2016 transfer to lender [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Net Rentable Area | ft²	698,000		698,000
Number of Real Estate Properties | bldg	6		6
Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Means Other than Sale [Member] | Mortgages [Member] | Joint venture, 2016 transfer to lender [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Debt amount extinguished			$ 112,500,000
Liberty Illinois, LP [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%
Liberty Illinois, LP [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture, 2016 sales [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Net Rentable Area | ft²	636,000		636,000
Number of Real Estate Properties | bldg	4		4
Proceeds from Sale of Property			$ 32,500,000
Liberty Illinois, LP [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Net Rentable Area | ft²	636,000		636,000
Number of Real Estate Properties | bldg	4		4
Proceeds from Sale of Property	$ 32,500,000
Cambridge Medipark Ltd [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
Gain on equity method investments [Member] | Cambridge Medipark Ltd [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture, 2016 sales [Member] | Leaseholds and Leasehold Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of leasehold interests			$ 3,500,000
Gain on equity method investments [Member] | Cambridge Medipark Ltd [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture, 2016 sales current quarter [Member] | Leaseholds and Leasehold Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of leasehold interests	$ 3,300,000
Gain on equity method investments [Member] | Cambridge Medipark Ltd [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture sales, 2015 [Member] | Leaseholds and Leasehold Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of leasehold interests		$ 89,000		$ 4,800,000
General Partner [Member] | Gain on equity method investments [Member] | Liberty Washington, LP [Member] | Discontinued Operations [Member] | Joint venture, 2016 sales [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of properties			6,000,000
General Partner [Member] | Gain on equity method investments [Member] | Liberty Washington, LP [Member] | Discontinued Operations [Member] | Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of properties	4,000,000
General Partner [Member] | Gain on equity method investments [Member] | Liberty Washington, LP [Member] | Discontinued Operations [Member] | Mortgages [Member] | Joint venture, 2016 transfer to lender [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on extinguishment of debt	0		4,200,000
General Partner [Member] | Gain on equity method investments [Member] | Liberty Illinois, LP [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture, 2016 sales [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of properties			$ 1,000,000
General Partner [Member] | Gain on equity method investments [Member] | Liberty Illinois, LP [Member] | Disposal Group, Not Discontinued Operations [Member] | Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of properties	$ 1,000,000

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Interest Rate Derivatives [Abstract]
Number of interest rate swap contracts	3		3
aggregate notional amount	$ 99,500		$ 99,500		$ 101,400
Termination value of interest rate swap, including accrued interest	7,000		7,000
Interest Rate Cash Flow Hedges [Abstract]
Fair value of interest rate swaps	6,900		6,900		$ 7,100
Amount estimated to be reclassified from accumulated other comprehensive income as an increase to interest expense	800		800
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 gain (loss) related to the effective portion recognized in other comprehensive loss	415	$ (1,570)	(1,928)	$ (2,592)
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 related to the effective portion subsequently reclassified to interest expense	(264)	(51)	(823)	(113)
Amount of gain (loss) related to the ineffective portion recognized in interest expense	$ 7	$ (350)	$ (71)	$ (1,053)

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Rental Payments (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
2016 (remaining)	$ 294,000		$ 294,000
2,017	1,429,000		1,429,000
2,018	1,685,000		1,685,000
2,019	1,685,000		1,685,000
2,020	1,685,000		1,685,000
2021 and thereafter	36,253,000		36,253,000
Total	43,031,000		43,031,000
Other Expenses [Abstract]
Operating ground lease expense	$ 241,000	$ 224,000	$ 734,000	$ 536,000

Commitments and Contingencies59

Commitments and Contingencies - Loss Contingencies (Details) $ in Millions	Sep. 30, 2016USD ($)
Legal Matters [Abstract]
Loss Contingency, Pending Claims, Number	0
Other [Abstract]
Letter of credit obligations	$ 7.5
Contractual Obligation	$ 4

Commitments and Contingencies60

Commitments and Contingencies - Supply Commitments (Details) $ in Thousands, ft² in Millions	Sep. 30, 2016USD ($)ft²propertiesbldg	Dec. 31, 2015USD ($)
Supply Commitment [Line Items]
Development in progress	$ 427,686	$ 360,948
Development not owned [Member] | Construction in Progress [Member]
Supply Commitment [Line Items]
Total anticipated development cost	$ 96,000
Construction in Progress [Member]
Supply Commitment [Line Items]
Net Rentable Area | ft²	6.6
Number of Real Estate Properties | properties	25
Total anticipated development cost	$ 606,200
Deferred leasing costs in development	11,300
Buildings and land parcels [Member]
Supply Commitment [Line Items]
Remaining amount committed or obligated to pay for the benefit of current or future tenants	38,400
Tenant Improvements [Member]
Supply Commitment [Line Items]
Tenant improvements not yet completed	$ 30,800
Equity Method Investments [Member] | Construction in Progress [Member] | Construction in Progress [Member]
Supply Commitment [Line Items]
Number of Real Estate Properties | bldg	3
Total anticipated development cost	$ 958,000

Commitments and Contingencies61

Commitments and Contingencies - Purchase Commitments (Details) $ in Millions	Sep. 30, 2016USD ($)
Land Purchases [Member]
Long-term Purchase Commitment [Line Items]
Remaining amount commitment to future land purchases	$ 29.4

Supplemental Disclosure to St62

Supplemental Disclosure to Statements of Cash Flows (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Write-off of fully depreciated/amortized property and deferred costs	$ 26,349,000	$ 44,216,000
Write-off of depreciated/amortized property and deferred costs due to sale/demolition	34,513,000	95,277,000
Write-off of costs related to early debt extinguishment	109,000	0
Conversion of Stock [Line Items]
Unrealized loss on cash flow hedge	(1,132,000)	(1,539,000)
Changes in accrued development capital expenditures	(7,522,000)	5,023,000
Capitalized equity-based compensation in development in progress	980,000	0
Common units into common shares [Member]
Conversion of Stock [Line Items]
Redemption of noncontrolling interests - common units	$ 132,000	$ 224,000

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Oct. 05, 2016
Subsequent Event [Line Items]
Proceeds from Sale of Buildings and Land				$ 142,808	$ 243,943
Loss on debt extinguishment		$ 3,494	$ 0	$ 3,494	$ 0
Unsecured Debt [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Loss on debt extinguishment	$ 23,300
6.625% Senior Note [Member] | Senior Notes [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Interest rate on notes						6.625%
Debt amount to be repurchased						$ 296,500
7.5% Medium Term Note [Member] | Medium-term Notes [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Interest rate on notes						7.50%
Debt amount to be repurchased						$ 100,000