Liberty Property Limited Partnership 10-Q 8 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2019	May 06, 2019
Entity Information [Line Items]
Entity Registrant Name	LIBERTY PROPERTY TRUST
Entity Central Index Key	0000921112
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Entity Emerging Growth Company	false
Entity Small Business	false
Amendment Flag	false
Entity Common Stock, Shares Outstanding		148,276,745
Liberty Property Limited Partnership
Entity Information [Line Items]
Entity Registrant Name	LIBERTY PROPERTY LIMITED PARTNERSHIP
Entity Central Index Key	0000921113

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Real estate:
Land and land improvements	$ 1,311,504	$ 1,241,593
Building and improvements	4,564,769	4,410,324
Less accumulated depreciation	(978,406)	(945,365)
Operating real estate	4,897,867	4,706,552
Development in progress	440,593	472,169
Land held for development	297,384	296,244
Net real estate	5,635,844	5,474,965
Cash and cash equivalents	96,949	84,923
Restricted cash	17,696	10,899
Accounts receivable	15,992	14,109
Deferred rent receivable	114,944	111,627
Deferred financing and leasing costs, net of accumulated amortization (March 31, 2019, $175,126; December 31, 2018, $165,786)	163,155	157,980
Investments in and advances to unconsolidated joint ventures	353,215	350,981
Assets held for sale	423,846	477,716
Right of use asset	18,097	0
Prepaid expenses and other assets	98,841	251,192
Total assets	6,938,579	6,934,392
LIABILITIES
Mortgage loans, net	396,690	395,202
Unsecured notes, net	2,632,089	2,285,698
Credit facilities	100,000	411,846
Accounts payable	51,267	65,260
Accrued interest	37,236	22,309
Dividend and distributions payable	62,229	60,560
Lease liabilities	18,752	0
Other liabilities	218,131	272,143
Liabilities held for sale	18,035	17,065
Total liabilities	3,534,429	3,530,083
Noncontrolling interest - operating partnership - 213,483 and 301,483 preferred units outstanding as of March 31, 2019 and December 31, 2018, respectively	5,337	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 148,258,042 and 147,899,354 shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	148	148
Additional paid-in capital	3,697,783	3,691,778
Accumulated other comprehensive loss	(51,803)	(55,243)
Distributions in excess of net income	(313,279)	(306,822)
Total Liberty Property Trust shareholders’ equity	3,332,849	3,329,861
Noncontrolling interest - operating partnership
Noncontrolling interest – operating partnership - 3,520,205 common units outstanding as of March 31, 2019 and December 31, 2018	61,280	61,471
Noncontrolling interest – consolidated joint ventures	4,684	5,440
Total equity	3,398,813	3,396,772
Total liabilities, noncontrolling interest - operating partnership and equity	6,938,579	6,934,392
Liberty Property Limited Partnership
Real estate:
Land and land improvements	1,311,504	1,241,593
Building and improvements	4,564,769	4,410,324
Less accumulated depreciation	(978,406)	(945,365)
Operating real estate	4,897,867	4,706,552
Development in progress	440,593	472,169
Land held for development	297,384	296,244
Net real estate	5,635,844	5,474,965
Cash and cash equivalents	96,949	84,923
Restricted cash	17,696	10,899
Accounts receivable	15,992	14,109
Deferred rent receivable	114,944	111,627
Deferred financing and leasing costs, net of accumulated amortization (March 31, 2019, $175,126; December 31, 2018, $165,786)	163,155	157,980
Investments in and advances to unconsolidated joint ventures	353,215	350,981
Assets held for sale	423,846	477,716
Right of use asset	18,097	0
Prepaid expenses and other assets	98,841	251,192
Total assets	6,938,579	6,934,392
LIABILITIES
Mortgage loans, net	396,690	395,202
Unsecured notes, net	2,632,089	2,285,698
Credit facilities	100,000	411,846
Accounts payable	51,267	65,260
Accrued interest	37,236	22,309
Dividend and distributions payable	62,229	60,560
Lease liabilities	18,752	0
Other liabilities	218,131	272,143
Liabilities held for sale	18,035	17,065
Total liabilities	3,534,429	3,530,083
Noncontrolling interest - operating partnership - 213,483 and 301,483 preferred units outstanding as of March 31, 2019 and December 31, 2018, respectively	5,337	7,537
EQUITY
General partner’s equity - 148,258,042 and 147,899,354 common units outstanding as of March 31, 2019 and December 31, 2018, respectively	3,332,849	3,329,861
Limited partners’ equity – 3,520,205 common units outstanding as of March 31, 2019 and December 31, 2018	61,280	61,471
Noncontrolling interest - operating partnership
Noncontrolling interest – consolidated joint ventures	4,684	5,440
Total equity	3,398,813	3,396,772
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,938,579	$ 6,934,392

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Deferred financing and leasing costs, accumulated amortization	$ 175,126	$ 165,786
Limited Partners' common units outstanding	3,520,205	3,520,205
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	148,258,042	147,899,354
Common shares of beneficial interest, shares outstanding	148,258,042	147,899,354
Liberty Property Limited Partnership
Deferred financing and leasing costs, accumulated amortization	$ 175,126	$ 165,786
Limited Partners' common units outstanding	3,520,205	3,520,205
Common shares of beneficial interest, shares outstanding	148,258,042	147,899,354
Series I-2
Noncontrolling interest - operating partnership, preferred units outstanding	213,483	301,483
Series I-2 | Liberty Property Limited Partnership
Noncontrolling interest - operating partnership, preferred units outstanding	213,483	301,483

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
REVENUE
Rental revenue	$ 156,886	$ 146,361
Development service fee income	864	26,352
Total revenue	157,750	172,713
EXPENSES
Rental property	13,620	13,260
Real estate taxes	22,462	21,578
General and administrative	15,607	14,335
Leasing expense	3,208	2,812
Other operating expense	2,268	2,502
Interest expense	25,519	22,670
Depreciation and amortization	43,484	39,659
Development service fee expense	833	28,067
Impairment charges - real estate assets	99	0
Total expenses	127,100	144,883
OTHER INCOME (EXPENSE)
Interest and other income	3,394	2,494
Gain on property dispositions	741	4,158
Equity in earnings of unconsolidated joint ventures	7,009	6,764
Income from continuing operations before income taxes	41,794	41,246
Income taxes	(832)	(528)
Income from continuing operations	40,962	40,718
Discontinued operations (including gain on sale net of impairments of $8.7 million on property dispositions for the three months ended March 31, 2019 and $90.0 million for the three months ended March 31, 2018)	14,786	103,007
Net income	55,748	143,725
Noncontrolling interest – operating partnership	(1,374)	(3,457)
Noncontrolling interest – consolidated joint ventures	(44)	(87)
Net income available to common shareholders	54,330	140,181
Comprehensive income attributable to common shareholders
Net income	55,748	143,725
Other comprehensive income - foreign currency translation	5,376	7,932
Other comprehensive (loss) income - derivative instruments	(1,854)	385
Other comprehensive income	3,522	8,317
Total comprehensive income	59,270	152,042
Less: comprehensive income attributable to noncontrolling interest	(1,500)	(3,738)
Comprehensive income attributable to common shareholders	$ 57,770	$ 148,304
Weighted average number of common shares or units outstanding
Basic (in shares)	147,559	147,060
Diluted (in shares)	148,540	147,873
Amounts attributable to common shareholders or unitholders
Income from continuing operations	$ 39,887	$ 39,574
Income from discontinued operations	14,443	100,607
Net income available to common shareholders or unitholders	54,330	140,181
Liberty Property Limited Partnership
REVENUE
Rental revenue	156,886	146,361
Development service fee income	864	26,352
Total revenue	157,750	172,713
EXPENSES
Rental property	13,620	13,260
Real estate taxes	22,462	21,578
General and administrative	15,607	14,335
Leasing expense	3,208	2,812
Other operating expense	2,268	2,502
Interest expense	25,519	22,670
Depreciation and amortization	43,484	39,659
Development service fee expense	833	28,067
Impairment charges - real estate assets	99	0
Total expenses	127,100	144,883
OTHER INCOME (EXPENSE)
Interest and other income	3,394	2,494
Gain on property dispositions	741	4,158
Equity in earnings of unconsolidated joint ventures	7,009	6,764
Income from continuing operations before income taxes	41,794	41,246
Income taxes	(832)	(528)
Income from continuing operations	40,962	40,718
Discontinued operations (including gain on sale net of impairments of $8.7 million on property dispositions for the three months ended March 31, 2019 and $90.0 million for the three months ended March 31, 2018)	14,786	103,007
Net income	55,748	143,725
Noncontrolling interest – operating partnership	(44)	(87)
Noncontrolling interest – consolidated joint ventures	(84)	(118)
Net income available to common shareholders	55,620	143,520
Comprehensive income attributable to common shareholders
Net income	55,748	143,725
Other comprehensive income - foreign currency translation	5,376	7,932
Other comprehensive (loss) income - derivative instruments	(1,854)	385
Other comprehensive income	3,522	8,317
Total comprehensive income	$ 59,270	$ 152,042
Weighted average number of common shares or units outstanding
Basic (in shares)	151,079	150,580
Diluted (in shares)	152,060	151,393
Net income allocated to general partners	$ 54,330	$ 140,181
Net income allocated to limited partners	1,374	3,457
Amounts attributable to common shareholders or unitholders
Income from continuing operations	40,918	40,631
Net income available to common shareholders or unitholders	$ 55,620	$ 143,520
Common Units | Liberty Property Limited Partnership
Basic:
Income from continuing operations (in usd per share)	$ 0.27	$ 0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - basic (in usd per share)	0.37	0.95
Diluted:
Income from continuing operations (in usd per share)	0.27	0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - diluted (in usd per share)	0.37	0.95
Common shares
Basic:
Income from continuing operations (in usd per share)	0.27	0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - basic (in usd per share)	0.37	0.95
Diluted:
Income from continuing operations (in usd per share)	0.27	0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - diluted (in usd per share)	$ 0.37	$ 0.95

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Gain on property dispositions in discontinued operations	$ 8,700,000	$ 90,000,000
Liberty Property Limited Partnership
Gain on property dispositions in discontinued operations	$ 8,700,000	$ 90,000,000

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	Total	COMMON SHARES OF BENEFICIAL INTEREST	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED OTHER COMPREHENSIVE LOSS	DISTRIBUTIONS IN EXCESS OF NET INCOME	TOTAL LIBERTY PROPERTY TRUST SHAREHOLDERS’ EQUITY	NONCONTROLLING INTEREST - OPERATING PARTNERSHIP	NONCONTROLLING INTEREST - CONSOLIDATED JOINT VENTURES	Common shares	Liberty Property Limited Partnership	Liberty Property Limited PartnershipGENERAL PARTNER	Liberty Property Limited PartnershipLIMITED PARTNER	Liberty Property Limited PartnershipNONCONTROLLING INTEREST - CONSOLIDATED JOINT VENTURES	Liberty Property Limited PartnershipTOTAL OWNERS’ EQUITY	Liberty Property Limited PartnershipCommon UnitsGENERAL PARTNER	Liberty Property Limited PartnershipCommon UnitsLIMITED PARTNER	Liberty Property Limited Partnership, Preferred Activity
Common shares outstanding - Beginning Balance (shares) at Dec. 31, 2017									147,450,691
General Partner's units outstanding - Beginning Balance (units) at Dec. 31, 2017															147,450,691
Limited Partners' units outstanding - Beginning Balance (units) at Dec. 31, 2017																3,520,205
Beginning balance at Dec. 31, 2017	$ 3,148,366	$ 147	$ 3,674,978	$ (37,797)	$ (549,970)	$ 3,087,358	$ 56,159	$ 4,849			$ 3,087,358	$ 56,159	$ 4,849	$ 3,148,366
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares	3,267	1	3,266			3,267
Net proceeds from issuance of common shares (shares)									322,450
Net income	143,607				140,181	140,181	3,339	87			140,181	3,339	87	143,607
Contributions from partners											8,683			8,683
Contributions from partners (units)															322,450
Distributions to partners											(59,094)	(1,506)	(85)	(60,685)
Distributions	(60,685)				(59,094)	(59,094)	(1,506)	(85)
Share-based compensation	5,416		5,416			5,416
Other comprehensive loss - foreign currency translation activity	7,932			7,747		7,747	185			$ 7,932	7,747	185		7,932
Other comprehensive income - derivative instruments activity	385			376		376	9			$ 385	376	9		385
Common shares outstanding - Ending Balance (shares) at Mar. 31, 2018									147,773,141
General Partner's units outstanding - Ending Balance (units) at Mar. 31, 2018															147,773,141
Limited Partners' units outstanding - Ending Balance (units) at Mar. 31, 2018																3,520,205
Ending balance at Mar. 31, 2018	3,248,288	148	3,683,660	(29,674)	(468,883)	3,185,251	58,186	4,851			3,185,251	58,186	4,851	3,248,288
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2017	7,537																$ 7,537
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (Mezzanine)	118																118
Distributions	(118)																(118)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Mar. 31, 2018	$ 7,537																7,537
Common shares outstanding - Beginning Balance (shares) at Dec. 31, 2018	147,899,354								147,899,354	147,899,354
General Partner's units outstanding - Beginning Balance (units) at Dec. 31, 2018															147,899,354
Limited Partners' units outstanding - Beginning Balance (units) at Dec. 31, 2018	3,520,205									3,520,205						3,520,205
Beginning balance at Dec. 31, 2018	$ 3,396,772	148	3,691,778	(55,243)	(306,822)	3,329,861	61,471	5,440		$ 3,396,772	3,329,861	61,471	5,440	3,396,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net proceeds from the issuance of common shares	3,909	0	3,909			3,909
Net proceeds from issuance of common shares (shares)									358,688
Net income	55,664				54,330	54,330	1,290	44			54,330	1,290	44	55,664
Contributions from partners											6,005			6,005
Contributions from partners (units)															358,688
Distributions to partners											(60,787)	(1,563)	(800)	(63,150)
Distributions	(63,150)				(60,787)	(60,787)	(1,563)	(800)
Share-based compensation	2,096		2,096			2,096
Other comprehensive loss - foreign currency translation activity	5,376			5,251		5,251	125			5,376	5,251	125		5,376
Other comprehensive income - derivative instruments activity	(1,854)			(1,811)		(1,811)	(43)			$ (1,854)	(1,811)	(43)		(1,854)
Redemption of noncontrolling interest - preferred units	$ (2,200)										0			0			(2,200)
Common shares outstanding - Ending Balance (shares) at Mar. 31, 2019	148,258,042								148,258,042	148,258,042
General Partner's units outstanding - Ending Balance (units) at Mar. 31, 2019															148,258,042
Limited Partners' units outstanding - Ending Balance (units) at Mar. 31, 2019	3,520,205									3,520,205						3,520,205
Ending balance at Mar. 31, 2019	$ 3,398,813	$ 148	$ 3,697,783	$ (51,803)	$ (313,279)	$ 3,332,849	$ 61,280	$ 4,684		$ 3,398,813	$ 3,332,849	$ 61,280	$ 4,684	$ 3,398,813
Noncontrolling Interest - Operating Partnership (Mezzanine) - Beginning Balance at Dec. 31, 2018	7,537									7,537							7,537
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (Mezzanine)	84																84
Distributions	(84)																(84)
Noncontrolling Interest - Operating Partnership (Mezzanine) - Ending Balance at Mar. 31, 2019	$ 5,337									$ 5,337							$ 5,337

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES
Net income	$ 55,748	$ 143,725
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	45,721	45,144
Amortization of deferred financing costs	1,201	967
Expensed pursuit costs	122	324
Impairment charges - real estate assets	10,373	0
Equity in earnings of unconsolidated joint ventures	(7,009)	(6,764)
Gain on property dispositions	(19,682)	(94,170)
Share-based compensation	9,641	9,633
Development service fee accrual	(23,249)	2,968
Other	(1,818)	(762)
Changes in operating assets and liabilities:
Accounts receivable	(2,247)	(706)
Deferred rent receivable	(4,177)	(4,944)
Prepaid expenses and other assets	13,670	20,312
Accounts payable	(13,874)	(9,003)
Accrued interest	14,927	13,059
Other liabilities	(25,587)	(26,084)
Net cash provided by operating activities	53,760	93,699
INVESTING ACTIVITIES
Investment in properties – acquisitions	(130,432)	(95,027)
Investment in properties – other	(7,392)	(3,603)
Investments in and advances to unconsolidated joint ventures	(3,240)	(66,420)
Distributions from unconsolidated joint ventures	8,209	11,521
Net proceeds from disposition of properties/land	87,609	184,233
Investment in development in progress	(68,026)	(51,932)
Investment in land held for development	(14,000)	(18,234)
Payment of deferred leasing costs	(4,653)	(2,183)
Release of escrows and other	130,160	126,745
Net cash (used in) provided by investing activities	(1,765)	85,100
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	3,909	3,267
Share repurchases, including shares related to tax withholdings	(7,981)	(4,402)
Redemption of preferred units	(2,200)	0
Proceeds from unsecured notes	349,097	0
Repayments of mortgage loans	(1,632)	(1,714)
Proceeds from credit facility	98,294	312,993
Repayments on credit facility	(410,140)	(414,757)
Payment of deferred financing costs	(3,408)	0
Distribution paid on common shares	(59,154)	(58,980)
Distributions to partners/noncontrolling interests	(2,412)	(1,651)
Net cash used in financing activities	(35,627)	(165,244)
Net increase in cash, cash equivalents and restricted cash	16,368	13,555
Increase in cash, cash equivalents and restricted cash related to foreign currency translation	2,455	506
Cash, cash equivalents and restricted cash at beginning of period	95,822	25,685
Cash, cash equivalents and restricted cash at end of period	114,645	39,746
Liberty Property Limited Partnership
OPERATING ACTIVITIES
Net income	55,748	143,725
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	45,721	45,144
Amortization of deferred financing costs	1,201	967
Expensed pursuit costs	122	324
Impairment charges - real estate assets	10,373	0
Equity in earnings of unconsolidated joint ventures	(7,009)	(6,764)
Gain on property dispositions	(19,682)	(94,170)
Share-based compensation	9,641	9,633
Development service fee accrual	(23,249)	2,968
Other	(1,818)	(762)
Changes in operating assets and liabilities:
Accounts receivable	(2,247)	(706)
Deferred rent receivable	(4,177)	(4,944)
Prepaid expenses and other assets	13,670	20,312
Accounts payable	(13,874)	(9,003)
Accrued interest	14,927	13,059
Other liabilities	(25,587)	(26,084)
Net cash provided by operating activities	53,760	93,699
INVESTING ACTIVITIES
Investment in properties – acquisitions	(130,432)	(95,027)
Investment in properties – other	(7,392)	(3,603)
Investments in and advances to unconsolidated joint ventures	(3,240)	(66,420)
Distributions from unconsolidated joint ventures	8,209	11,521
Net proceeds from disposition of properties/land	87,609	184,233
Investment in development in progress	(68,026)	(51,932)
Investment in land held for development	(14,000)	(18,234)
Payment of deferred leasing costs	(4,653)	(2,183)
Release of escrows and other	130,160	126,745
Net cash (used in) provided by investing activities	(1,765)	85,100
FINANCING ACTIVITIES
Redemption of preferred units	(2,200)	0
Proceeds from unsecured notes	349,097	0
Repayments of mortgage loans	(1,632)	(1,714)
Proceeds from credit facility	98,294	312,993
Repayments on credit facility	(410,140)	(414,757)
Payment of deferred financing costs	(3,408)	0
Capital contributions	3,909	3,267
Distributions to partners/noncontrolling interests	(69,547)	(65,033)
Net cash used in financing activities	(35,627)	(165,244)
Net increase in cash, cash equivalents and restricted cash	16,368	13,555
Increase in cash, cash equivalents and restricted cash related to foreign currency translation	2,455	506
Cash, cash equivalents and restricted cash at beginning of period	95,822	25,685
Cash, cash equivalents and restricted cash at end of period	$ 114,645	$ 39,746

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	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 March 31, 2019 . The Company owns and operates industrial properties in the United States nationally, as well as in the United Kingdom. The Company intends to divest its remaining office properties (other than its headquarters) over the next few years and focus its efforts and capital solely on its industrial platform. 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. 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 $74.3 million and $75.1 million as of March 31, 2019 and December 31, 2018, 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 (“U.S. 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 U.S. 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, 2018 . 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. Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”), which supersedes nearly all existing revenue recognition guidance (except revenue in the scope of other accounting standards, including standards related to leasing). Subsequently, the FASB issued supplementary standards providing additional guidance and targeted improvements to ASU 2014-09 (collectively, the “Revenue Standards”). The Revenue Standards provide a unified model to determine how revenue is recognized. In accordance with the Revenue Standards, the Company performs the following steps: (i) identify the contract with the customer, (ii) identify the performance obligations within the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations and (v) recognize revenue when (or as) a performance obligation is satisfied. Upon adoption of the Revenue Standards, the Company evaluated each of its revenue streams: lease agreement revenue, development service fee revenue, deferred land sale revenue and gain or loss on sale of nonfinancial assets. The Company concluded that there are no revenue streams from its lease agreements that are covered by the Revenue Standards with the possible exception of non-lease components as further discussed below. The Revenue Standards did not have an impact on the amount and timing of recognizing the Company's development service fee income. The Company recognizes development service fee income on a variable basis as a percentage of costs incurred on third party development contracts. Property development services, which are a single performance obligation, continue to be satisfied and recognized over time. The Company measures its progress toward completing the performance obligations under each arrangement. The measurement of the transfer of value to the customer for these services utilizes the input method (actual costs incurred against anticipated project costs) since this method best depicts the actual transfer of value promised to the customer. Estimated expected losses on such contracts are accrued in the period in which they are determinable. The total amount of consideration to be received from these projects is assessed on a quarterly basis. Based on existing contracts, completion is anticipated during 2019. The Company recognizes revenues from improving land sites and selling the underlying land on behalf of its development partner to home builders in the United Kingdom. These agreements contain a pre-emption clause and a seller's call option. The Company recognizes revenue as the pre-emption period or seller's call option lapses utilizing the output method. There was $3.7 million in revenue recognized for such contracts during the three months ended March 31, 2019. The Revenue Standards did not have an impact on the gain or loss on sale of nonfinancial assets. The Revenue Standards require the Company to derecognize nonfinancial assets once it transfers control of a distinct nonfinancial asset or distinct in-substance nonfinancial asset. Additionally, when the Company transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling ownership interest, the Company is required to measure any noncontrolling interest it receives or retains at fair value. The guidance requires companies to recognize a full gain or loss on the transaction. See Notes 5 and 7 for further discussion of sales of nonfinancial assets during the three months ended March 31, 2019. Estimated gross revenue related to the remaining performance obligations under existing contracts (before allocation of related costs and expenses) as of March 31, 2019 that will be recognized as revenue in future periods was approximately $34.2 million , which is expected to be recognized in 2019 through 2021. Recently Issued Accounting Standards Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update 2016-02, Leases (“ASU 2016-02”). Additional guidance and targeted improvements to ASU 2016-02 were made through the issuances of supplementary ASUs in July 2018, December 2018 and March 2019 (collectively, the "New Lease Standard"). The New Lease Standard sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). It requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. The New Lease Standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales type leases, direct financing leases and operating leases. The New Lease Standards limit capitalization of certain initial direct costs which were previously capitalizable under previous lease standards. Such costs which were expensed during the three months ended March 31, 2019 were $ 0.3 million . The Company adopted the New Lease Standard on January 1, 2019 and applied it using a modified retrospective approach whereby the cumulative effect of the adoption was recognized on the adoption date and prior periods were not restated. There was no net cumulative effect adjustment to retained earnings as of January 1, 2019 as a result of this adoption. The following practical expedients available for implementation were elected: a. whether an expired or existing contract meets the definition of a lease b. the lease classification at the adoption date for existing or expired leases c. whether costs previously capitalized as initial direct costs would continue to be amortized Additionally, the Company has elected the practical expedient not to recognize right of use assets and lease liabilities with a term of one year or less. The Company's leases met the criteria in the New Lease Standard to not separate non-lease components from the related lease component; therefore, the accounting for these leases remained largely unchanged from the previous standard. The Company has elected to exclude sales and other similar taxes from the measurement of lease revenue and expense and the Company has excluded those costs paid directly by lessees to third parties. Lessee Disclosure As of March 31, 2019, the Company had a total of five properties subject to operating ground leases in Florida, New Jersey, Kentucky and the United Kingdom with a weighted average remaining term of 47 years. These leases have remaining terms of 11 to 110 years, expiration dates of June 2030 to June 2129, and renewal options of 25 to 48 years. The Company has included in the lease terms renewal options to the useful life of the asset constructed on the land. Payments for certain properties are subject to increases at five -year intervals based upon the agreed or appraised fair market value of the leased premises on the adjustment date or the Consumer Price Index percentage increase since the base rent date. These future changes in payments are considered variable payments and do not impact the assessment of the asset or liability unless there is a significant event that triggers reassessment, such as an amendment with a change in the terms of the lease. The Company used discount rates in a range of 4.1% to 5.0% for a weighted average discount rate of 4.6% , which was derived from the Company's assessment of credit quality of the Company adjusted to reflect secured borrowing, estimated yield curves and long-term spread adjustments over appropriate tenors. The Company also leases office space from unrelated third-parties. The Company recognized $468,000 of lease expense, of which $433,000 was paid in cash, during the three months ended March 31, 2019. The following schedule indicates the approximate future minimum lease payments for the ground and office leases as of March 31, 2019: Year Amount 2019 (remainder of year) $ 1,134 2020 1,376 2021 1,235 2022 1,137 2023 1,036 Thereafter 40,842 Total minimum payments $ 46,760 Imputed interest (27,833 ) Amortization (175 ) Lease liabilities $ 18,752 Deferred rent (655 ) Right of use asset $ 18,097 As noted above, the Company adopted the New Lease Standard effective January 1, 2019. Since the Company has applied the provisions on a modified retrospective basis, the following represents approximate future minimum lease payments by year as of December 31, 2018, as applicable under ASC 840, Leases, prior to the adoption of the New Lease Standard. Year Amount 2019 $ 1,512 2020 1,356 2021 1,205 2022 1,082 2023 981 Thereafter 40,799 $ 46,935 The Company recorded ground lease expense of $1.5 million for the year ended December 31, 2018. Lessor Disclosures The Company leases its operating properties to customers under agreements that are classified as operating leases. It manages residual risk through investing in properties that it believes will appreciate in value over time. Substantially all of the Company's operating leases contain provisions for specified annual increases over the rents of the prior year. Rental income from operating leases is generally recognized on a straight-line basis over the lease term when the Company has determined that the collectibility of substantially all the lease payments is probable. If the Company determines that it is not probable that substantially all of the lease payments will be collected, the Company accounts for the revenue under the lease on a cash basis. Changes in the assessment of probability are accounted for on a cumulative basis as if the lease had always been accounted for based on the current determination of the likelihood of collection potentially resulting in increased volatility of rental revenue. Some of the Company's leases have options to extend, terminate or purchase the facilities, which are considered when determining the lease term. Tenant rights to purchase an underlying asset are at prevailing market rates at the time of purchase. The Company does not include in measurement of lease receivables certain variable payments, including changes in an index, until the specific events that trigger the variable payments have occurred. Generally operating leases require the tenants to reimburse the Company for property tax and other expenditures that are not considered components of the lease and therefore no consideration is allocated to them as they do not result in the transfer of a good or service to the tenants. The Company has determined that all of its leases qualify for the practical expedient to not separate the lease and non-lease components because (i) the lease components are operating leases and (ii) the timing and pattern of recognition of the non-lease components are the same as the lease components. The Company applies the New Lease Standard to the combined component. Income derived from the Company's leases is recorded in rental revenue in the Company's consolidated statement of comprehensive income. Certain tenants are obligated to pay directly their obligations under their leases for real estate taxes, insurance and certain other expenses. These obligations, which have been assumed by the tenants under the terms of their respective leases, are not reflected in the Company's consolidated financial statements. To the extent any tenant responsible for these obligations under the respective lease defaults on its lease or if it is deemed probable that the tenant will fail to pay for such costs, the Company would record a liability for such obligation. The following details the rental income and variable lease income for the three months ended March 31, 2019: For the Three Months Ended March 31, 2019 (in thousands) Rental income - operating leases - continuing operations $ 121,538 Rental income - operating leases - discontinued operations 10,204 Variable lease income - operating leases - continuing operations 35,348 Variable lease income - operating leases - discontinued operations 3,060 The following amounts reflect the estimated contractual rents due to the Company for the remainder of terms of the Company's operating leases as of March 31, 2019: (in thousands) Remainder of 2019 $ 384,744 2020 481,612 2021 412,630 2022 342,633 2023 279,153 2024 227,300 Thereafter 854,364 Total $ 2,982,436 Other In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities ("ASU 2017-12"). ASU 2017-12 is designed to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. The Company adopted ASU 2017-12 on January 1, 2019 and it did not have a material impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software: Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract ("ASU 2018-15"). ASU 2018-15 amends the definition of a hosting arrangement and requires a customer in a hosting arrangement that is a service contract to capitalize certain implementation costs as if the arrangement was an internal-use software project. ASU 2018-15 is effective for the Company beginning January 1, 2020. Upon adoption, the Company does not anticipate the impact of ASU 2018-15 will have a material impact on the consolidated financial statements.

Income per Common Share of the

Income per Common Share of the Trust	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Income per Common Share of the Trust	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): Three Months Ended Three Months Ended March 31, 2019 March 31, 2018 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 39,887 147,559 $ 0.27 $ 39,574 147,060 $ 0.27 Dilutive shares for long-term compensation plans — 981 — 813 Income from continuing operations net of noncontrolling interest - diluted $ 39,887 148,540 $ 0.27 $ 39,574 147,873 $ 0.27 Discontinued operations net of noncontrolling interest - basic $ 14,443 147,559 $ 0.10 $ 100,607 147,060 $ 0.68 Dilutive shares for long-term compensation plans — 981 — 813 Discontinued operations net of noncontrolling interest - diluted $ 14,443 148,540 $ 0.10 $ 100,607 147,873 $ 0.68 Net income available to common shareholders - basic $ 54,330 147,559 $ 0.37 $ 140,181 147,060 $ 0.95 Dilutive shares for long-term compensation plans — 981 — 813 Net income available to common shareholders - diluted $ 54,330 148,540 $ 0.37 $ 140,181 147,873 $ 0.95 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. There were no anti-dilutive options excluded from the computation of diluted income per common share for the three months ended March 31, 2019 or 2018 . During the three months ended March 31, 2019 , 109,000 common shares were issued upon the exercise of options. During the year ended December 31, 2018 , 151,000 common shares were issued upon the exercise of options. Share Repurchase The Company’s Board of Trustees has authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common shares through September 28, 2019. 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. There were no purchases under the plan during the three months ended March 31, 2019 or for the year ended December 31, 2018.

Income per Common Unit of the O

Income per Common Unit of the Operating Partnership	3 Months Ended
	Mar. 31, 2019
Earnings Per Unit, Basic and Diluted [Line Items]
Income per Common Share of the Trust	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): Three Months Ended Three Months Ended March 31, 2019 March 31, 2018 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 39,887 147,559 $ 0.27 $ 39,574 147,060 $ 0.27 Dilutive shares for long-term compensation plans — 981 — 813 Income from continuing operations net of noncontrolling interest - diluted $ 39,887 148,540 $ 0.27 $ 39,574 147,873 $ 0.27 Discontinued operations net of noncontrolling interest - basic $ 14,443 147,559 $ 0.10 $ 100,607 147,060 $ 0.68 Dilutive shares for long-term compensation plans — 981 — 813 Discontinued operations net of noncontrolling interest - diluted $ 14,443 148,540 $ 0.10 $ 100,607 147,873 $ 0.68 Net income available to common shareholders - basic $ 54,330 147,559 $ 0.37 $ 140,181 147,060 $ 0.95 Dilutive shares for long-term compensation plans — 981 — 813 Net income available to common shareholders - diluted $ 54,330 148,540 $ 0.37 $ 140,181 147,873 $ 0.95 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. There were no anti-dilutive options excluded from the computation of diluted income per common share for the three months ended March 31, 2019 or 2018 . During the three months ended March 31, 2019 , 109,000 common shares were issued upon the exercise of options. During the year ended December 31, 2018 , 151,000 common shares were issued upon the exercise of options. Share Repurchase The Company’s Board of Trustees has authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common shares through September 28, 2019. 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. There were no purchases under the plan during the three months ended March 31, 2019 or for the year ended December 31, 2018.
Liberty Property Limited Partnership
Earnings Per Unit, Basic and Diluted [Line Items]
Income per Common Share of the Trust	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): Three Months Ended Three Months Ended March 31, 2019 March 31, 2018 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations - net of noncontrolling interest - consolidated joint ventures $ 40,918 $ 40,631 Less: Preferred unit distributions (84 ) (118 ) Income from continuing operations available to common unitholders - basic $ 40,834 151,079 $ 0.27 $ 40,513 150,580 $ 0.27 Dilutive units for long-term compensation plans — 981 — 813 Income from continuing operations available to common unitholders - diluted $ 40,834 152,060 $ 0.27 $ 40,513 151,393 $ 0.27 Income from discontinued operations - basic $ 14,786 151,079 $ 0.10 $ 103,007 150,580 $ 0.68 Dilutive units for long-term compensation plans — 981 — 813 Income from discontinued operations - diluted $ 14,786 152,060 $ 0.10 $ 103,007 151,393 $ 0.68 Income available to common unitholders - basic $ 55,620 151,079 $ 0.37 $ 143,520 150,580 $ 0.95 Dilutive units for long-term compensation plans — 981 — 813 Income available to common unitholders - diluted $ 55,620 152,060 $ 0.37 $ 143,520 151,393 $ 0.95 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. There were no anti-dilutive options excluded from the computation of diluted income per common unit for the three months ended March 31, 2019 or 2018 . During the three months ended March 31, 2019 , 109,000 common units were issued upon exercise of options. During the year ended December 31, 2018 , 151,000 common units were issued upon the exercise of options. Unit Repurchase The Company’s Board of Trustees has authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common units through September 28, 2019. 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. There were no purchases under the plan during the three months ended March 31, 2019 or for the year ended December 31, 2018.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Loss The following table sets forth the components of Accumulated Other Comprehensive Loss (in thousands): As of and for the three months ended March 31, 2019 2018 Foreign Currency Translation: Beginning balance $ (52,862 ) $ (38,701 ) Translation adjustment 5,376 7,932 Ending balance (47,486 ) (30,769 ) Derivative Instruments: Beginning balance (3,550 ) 150 Unrealized gain (1,830 ) 369 Reclassification adjustment (1) (24 ) 16 Ending balance (5,404 ) 535 Total accumulated other comprehensive loss (52,890 ) (30,234 ) Less: portion included in noncontrolling interest – operating partnership 1,087 560 Total accumulated other comprehensive loss included in shareholders' equity/owners' equity $ (51,803 ) $ (29,674 ) (1) Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate

Real Estate	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Real Estate	Real Estate Information on the Operating Properties and land parcels the Company acquired during the three months ended March 31, 2019 is as follows: Three Months Ended March 31, 2019 Number of Buildings Acres of Developable Land Leaseable Square Feet Purchase Price (in thousands) Dallas 2 — 509,733 $ 44,400 Southern California 1 — 289,683 31,285 United Kingdom — 25.0 — 2,658 Other: Atlanta — 154.7 — 5,000 New Jersey 2 — 270,254 51,775 5 179.7 1,069,670 $ 135,118 Information on the Operating Properties and land parcels the Company sold during the three months ended March 31, 2019 is as follows: Three Months Ended March 31, 2019 Number of Buildings Acres of Developable Land Leaseable Square Feet Gross Proceeds (in thousands) Florida 3 — 150,751 $ 23,400 Other New Jersey — 0.8 — 4,000 DC Metro 1 — 146,472 61,750 4 0.8 297,223 $ 89,150

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2019
Segment Reporting [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 three months ended March 31, 2019, the Company realigned its reportable segments as follows: • Carolinas/Richmond; • Chicago/Minneapolis; • Cincinnati/Columbus/Indianapolis; • Dallas • Florida; • Houston; • Lehigh/Central PA; • Philadelphia; • Southern California; and • United Kingdom. Certain other segments are aggregated into an "Other" category which includes the reportable segments: Arizona; Atlanta; DC Metro; New Jersey; and Southeastern Pennsylvania. 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 Ended March 31, 2019 March 31, 2018 Revenue Carolinas/Richmond $ 20,086 $ 19,793 Chicago/Minneapolis 17,415 16,517 Cincinnati/Columbus/Indianapolis 4,341 4,822 Dallas 5,517 4,085 Florida 16,283 15,408 Houston 16,091 15,862 Lehigh/Central PA 40,208 38,085 Philadelphia 11,338 12,345 Southern California 9,551 6,795 United Kingdom 5,998 4,273 Other 23,552 34,103 Segment-level revenue 170,380 172,088 Reconciliation to total revenue Development service fee income 864 26,352 Discontinued operations (13,264 ) (25,631 ) Other (230 ) (96 ) Total revenue $ 157,750 $ 172,713 Net operating income Carolinas/Richmond $ 14,332 $ 14,047 Chicago/Minneapolis 10,335 9,901 Cincinnati/Columbus/Indianapolis 2,770 3,268 Dallas 3,390 2,473 Florida 11,436 10,819 Houston 8,865 9,597 Lehigh/Central PA 28,427 27,767 Philadelphia 8,075 10,154 Southern California 7,447 5,228 United Kingdom 2,981 2,429 Other 14,214 22,471 Net operating income 112,272 118,154 Reconciliation to income from continuing operations Interest expense (1) (26,205 ) (23,459 ) Depreciation/amortization expense (1) (2) (33,585 ) (33,408 ) Gain on property dispositions 741 4,158 Equity in earnings of unconsolidated joint ventures 7,009 6,764 General and administrative expense (1) (2) (13,158 ) (10,725 ) Leasing cost (3,208 ) (2,812 ) Other operating expenses (2) (2,268 ) (2,502 ) Discontinued operations excluding gain and impairment on property dispositions (6,119 ) (12,995 ) Income taxes (1) (2) (242 ) (12 ) Other 5,725 (2,445 ) Income from continuing operations $ 40,962 $ 40,718 (1) Includes activity in discontinued operations. (2) Excludes costs that are included in determining net operating income. The Company's total assets by reportable segment as of March 31, 2019 and December 31, 2018 is as follows (in thousands): March 31, 2019 December 31, 2018 Carolinas/Richmond $ 526,631 $ 525,041 Chicago/Minnesota 588,169 591,792 Cincinnati/Columbus/Indianapolis 132,501 131,400 Dallas 305,929 261,538 Florida 543,304 547,232 Houston 586,409 568,756 Lehigh/Central PA 1,208,754 1,210,220 Philadelphia 609,011 624,373 Southern California 703,117 660,688 United Kingdom 409,821 463,162 Other 1,152,581 1,153,518 Segment-level total assets 6,766,227 6,737,720 Corporate Other 172,352 196,672 Total assets $ 6,938,579 $ 6,934,392

Impairment and Disposal of Long

Impairment and Disposal of Long-Lived Assets	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Impairment and Disposal of Long-Lived Assets	7 : Impairment or Disposal of Long-Lived Assets In 2017, the Company initiated a strategic shift whereby it planned to divest of its remaining suburban office properties. In the third quarter of 2018, the Company updated its strategy whereby it plans to divest of all of its remaining office properties. The Company determined that the strategic shift would have a major effect on its operations and financial results. As such, properties sold or those that meet the criteria to be classified as held for sale within the corporate strategy were classified within discontinued operations. Consistent with the held for sale criteria these properties are expected to be sold within one year . As the result of the classification within discontinued operations, the in-service assets and liabilities of this portfolio are required to be presented as held for sale for all prior periods presented in our Consolidated Balance Sheets. Operating results pertaining to these properties were reclassified to discontinued operations for all prior periods presented in our Consolidated Statements of Comprehensive Income. The following table illustrates the number of sold or held for sale properties included in, or excluded from, discontinued operations: Held for Sale as of March 31, 2019 Sold during the three months ended March 31, 2019 Sold during the year ended December 31, 2018 Total Properties included in discontinued operations 16 4 37 57 Properties included in continuing operations 2 — 2 4 Properties sold or classified as held for sale 18 4 39 61 The properties held for sale with operating results in discontinued operations as of March 31, 2019 were located in the following reportable segments: five properties in Southeastern PA, one property in Chicago/Minneapolis, nine properties in Philadelphia and one property in DC Metro. A summary of the results of operations for the properties classified as discontinued operations is as follows (in thousands): Three Months Ended March 31, 2019 March 31, 2018 Revenues $ 13,264 $ 25,631 Operating expenses (4,288 ) (6,572 ) Depreciation and amortization (1,981 ) (5,246 ) Impairment expense (10,274 ) — Interest and other income (158 ) (3 ) Income taxes (32 ) (26 ) Interest expense (686 ) (789 ) Gain on property dispositions 18,941 90,012 Income from discontinued operations 14,786 103,007 Noncontrolling interest - operating partnership (343 ) (2,400 ) Income from discontinued operations available to common shareholders $ 14,443 $ 100,607 Interest expense has been allocated to discontinued operations. The allocation of interest expense to discontinued operations was based on the ratio of net assets sold and held for sale included in discontinued operations to the sum of total net assets plus consolidated debt. Capital expenditures on a cash basis related to properties within discontinued operations for the three months ended March 31, 2019 and 2018 were $1.5 million and $16.2 million , respectively. Assets Held for Sale As of March 31, 2019 , 18 properties were classified as held for sale, of which 16 properties met the criteria to be classified within discontinued operations and two properties were classified within continuing operations. The following table illustrates aggregate balance sheet information for all held for sale properties (in thousands): March 31, 2019 December 31, 2018 Included in Continuing Operations Included in Discontinued Operations Total Included in Continuing Operations Included in Discontinued Operations Total Land and land improvements $ 2,444 $ 88,251 $ 90,695 $ 1,301 $ 108,001 $ 109,302 Buildings and improvements 16,577 297,375 313,952 5,638 371,461 377,099 Land held for development 36,957 — 36,957 26,253 — 26,253 Accumulated depreciation (2,814 ) (45,440 ) (48,254 ) (1,546 ) (66,176 ) (67,722 ) Deferred financing and leasing costs, net 382 12,443 12,825 58 13,539 13,597 Other assets 796 16,875 17,671 164 19,023 19,187 Total assets held for sale $ 54,342 $ 369,504 $ 423,846 $ 31,868 $ 445,848 $ 477,716 Total liabilities held for sale $ 3,695 $ 14,340 $ 18,035 $ 141 $ 16,924 $ 17,065 Impairment Charges - Real Estate Assets The Company recorded $10.4 million of impairment charges during the three months ended March 31, 2019 . There were no such charges during the three months ended March 31, 2018. Of the impairment charges recorded in the current year quarter, $10.3 million was related to an office building held for sale in the Company's DC Metro segment and is included in discontinued operations in the Company's Consolidated Statements of Comprehensive Income. The remaining $99,000 of impairment was related to a land parcel held for sale in the Company's Houston segment and is classified as continuing operations. 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. The Company has applied reasonable estimates and judgments in evaluating each of its properties and land held for development and has determined that there are no additional valuation adjustments necessary at March 31, 2019 . 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 additional impairment charges in the future.

Noncontrolling Interests of the

Noncontrolling Interests of the Trust	3 Months Ended
	Mar. 31, 2019
Stockholders' Equity Attributable to Noncontrolling Interest [Abstract]
Noncontrolling Interests of the Trust	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 March 31, 2019 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 March 31, 2019 was $ 170.4 million .

Limited Partners' Equity and No

Limited Partners' Equity and Noncontrolling Interest of the Operating Partnership	3 Months Ended
	Mar. 31, 2019
Preferred Units [Line Items]
Limited Partners' Equity and Noncontrolling Interest of the Operating Partnership	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 March 31, 2019 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 March 31, 2019 was $ 170.4 million .
Liberty Property Limited Partnership
Preferred Units [Line Items]
Limited Partners' Equity and Noncontrolling Interest of the Operating Partnership	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 March 31, 2019 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 based on the closing price of the common shares of the Trust at March 31, 2019 was $ 170.4 million .

Noncontrolling Interest - Opera

Noncontrolling Interest - Operating Partnership/Limited Partnership/Limited Partners' Equity - Preferred Units	3 Months Ended
	Mar. 31, 2019
Temporary Equity [Line Items]
Noncontrolling Interest - Operating Partnership/Limited Partnership/Limited Partners' Equity - Preferred Units	Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units As of March 31, 2019 , 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 $ 5,337 213 $ 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. During the three months ended March 31, 2019, 88,000 preferred units were redeemed for $2.2 million .

Indebtedness

Indebtedness	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Indebtedness	Indebtedness In January 2019, the Company issued $350 million of 4.375% senior unsecured notes due 2029. The net proceeds from this issuance were used to repay borrowings under the Company's unsecured credit facilities and for general corporate purposes.

Disclosure of Fair Value of Fin

Disclosure of Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2019
Debt Instrument, Fair Value Disclosure [Abstract]
Disclosure of Fair Value of Financial Instruments	Fair Value of Financial Instruments ASC 820, Fair Value Measurements and Disclosures , provides guidance on the fair value measurement of a financial asset or liability. Inputs used to develop fair value are classified in one of three categories: Level 1 inputs (quoted prices (unadjusted) in active markets for identical assets or liabilities), Level 2 inputs (inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly) and Level 3 inputs (unobservable inputs for the asset or liability). 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 December 31, 2018 and March 31, 2019 . 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 facilities 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 December 31, 2018 and March 31, 2019 . 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, 2018 and March 31, 2019 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2018 $ 395,202 $ 397,167 $ 2,285,698 $ 2,295,699 As of March 31, 2019 $ 396,690 $ 396,930 $ 2,632,089 $ 2,722,758

Unconsolidated Joint Ventures

Unconsolidated Joint Ventures	3 Months Ended
	Mar. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Unconsolidated Joint Ventures	Unconsolidated Joint Ventures Liberty Property 18th & Arch LP and Liberty Property 18th & Arch Hotel, LP On June 30, 2014, the Company entered into two joint ventures for the purpose of developing and owning the Comcast Technology Center (the “Project”) located in Philadelphia, Pennsylvania as part of a mixed-use development. The 60 -story building includes 1.3 million square feet of leasable office space (the “Office”), which is substantially complete, and will include a 219 -room Four Seasons Hotel (the “Hotel”) (collectively, “Liberty Property 18th and Arch”). Project costs for the development of the Project, exclusive of tenant-funded interior improvements, are anticipated to be approximately $962 million . As of March 31, 2019, the Company's investment in the project is $193 million and is reflected in investments in and advances to unconsolidated joint ventures in the Company's consolidated balance sheet. These joint ventures are part of the Company's Philadelphia reportable segment. As of March 31, 2019 the Office was substantially complete and the Hotel, representing an aggregate Total Investment by the Hotel joint venture of $226.1 million when completed, continued to be developed by the Hotel joint venture. The two joint ventures have engaged the Company as the developer of the Project pursuant to a Development Agreement by which the Company agrees, in consideration for a development fee, to be responsible for all aspects of the development of the Project and to guarantee the timely lien-free completion of construction of the Project as well as the payment, subject to certain exceptions, of any cost overruns incurred in the development of the Project. To mitigate its risk, the Company entered into guaranteed maximum price contracts with a third party contractor (the "GMP Contracts") to construct the Project. The Company has been notified by its third-party contractor that the contractor has incurred cost overruns and expects to incur additional construction costs in connection with completing the Project in excess of the guaranteed maximum price payable to the contractor under the GMP Contracts, which guaranteed maximum price has been previously adjusted pursuant to accepted change orders. The Company intends to pursue all remedies to recover from the third-party contractor any amounts expended by the Company or the joint ventures in excess of their contractual obligations. However, the general contractor has generally refused to fund the additional costs, and the Company has funded, and may continue to fund, cost overruns in compliance with its obligations under its development cost guarantee to the joint ventures. Accordingly, reflective of amounts funded by the Company, a s of March 31, 2019 and December 31, 2018, the Company's accrual was $44.5 million and $67.3 million , respectively, relating to the above-described development cost guarantees, which are included in other liabilities in the accompanying consolidated balance sheets. The Company is accounting for the development of the Project using the percentage of completion method. The Company recognized a loss of $1.8 million for the three months ended March 31, 2018 in development service fee income, net of development service fee expense and other related expenses. There was no loss or gain recognized related to the Project during the three months ended March 31, 2019. In addition to the costs to comply with the Company's obligations under its development cost guarantee, claims have been asserted by the third-party contractor and certain subcontractors. There can be no assurances that amounts incurred, including as a result of such claims, will not exceed the above estimates. The Company is not able to reasonably estimate the amount of additional expenses, if any, that it may incur as a result of such claims, and accordingly any potential exposure of the Company for such claims is not included within the accrual described above. If the Company were to incur additional expenses in connection with its development cost guarantee or in connection with such claims, such amounts would be accrued when they are determined to be probable of being incurred and are reasonably estimable, and could be material to the Company’s results of operations in future periods. If the Company were to subsequently recover any of the cost overruns initially funded by the Company, such recoveries would be recorded when and if realized in future periods. Cambridge Medipark Ltd During the three months ended March 31, 2019 and 2018, 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 $775,000 and $2.0 million for the three months ended March 31, 2019 and 2018, respectively.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	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. Other 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. 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 changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive loss and noncontrolling interest (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 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 two 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 $66.3 million and $66.8 million at March 31, 2019 and December 31, 2018 , respectively, and expire in 2020 . In addition, in 2018, in anticipation of conducting the offering of senior notes described in Note 11, the Operating Partnership entered into two interest rate lock agreements tied to the U.S. treasury rate for an aggregate notional amount of $200 million . An interest rate lock is a tool used to manage interest-rate risk by effectively securing interest rates on federal government securities as of the agreement date, to cover future expenses that will be financed by a debt offering. One agreement had a notional amount of $100 million and expired and was settled in 2018 for $2.4 million . The second agreement had a notional amount of $100 million and expired in 2019. It was settled prior to consummation of the January 2019 offering of senior notes for $3.3 million . The interest rate lock agreements qualified as cash flow hedges with respect to the senior notes offering and, as such, the settlements of $5.7 million will be amortized into interest expense over the respective term of the notes. The Company accounts for the changes in the fair value of a derivative in accumulated other comprehensive loss and subsequently reclassifies amounts to earnings over the term that the hedged transaction affects 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 months ended March 31, 2019 and 2018 (in thousands): Three Months Ended March 31, 2019 March 31, 2018 Amount of gain related to the effective portion recognized in other comprehensive (loss) income $ 559 $ 402 Total Amount of Interest Expense Presented in the Consolidated Statements of Comprehensive Income 25,519 22,670 The following table presents the fair value of the Company’s derivative financial instruments as well as their classification on the accompanying consolidated balance sheets as of March 31, 2019 and December 31, 2018 (amounts in thousands): Derivatives Fair Value at: Balance Sheet Location March 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest Rate Swaps Other Liabilities $ 591 $ 677 Interest Rate Treasury Locks Other Liabilities — 3,972 Total $ 591 $ 4,649 Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt. The Company estimates that $0.2 million will be reclassified from accumulated other comprehensive loss as an increase to interest expense over the next 12 months. The Company has agreements with its derivative counterparties that contain a provision whereby if the Company defaults on any of its indebtedness, including defaults where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. If the Company were to breach any of the contractual provisions of the derivative contracts, it would be required to settle its obligations under the agreements at their termination value including accrued interest, which totaled approximately $0.7 million as of March 31, 2019 .

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
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. 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 March 31, 2019 there were no legal proceedings, claims or assessments that the Company expects to have a material adverse effect on the Company. However, see Note 13 for discussion of Comcast Technology Center. Other As of March 31, 2019 , the Company had letter of credit obligations of $8.3 million . As of March 31, 2019 , the Company had 25 buildings under development. These buildings are expected to contain, when completed, a total of 7.5 million square feet of leasable space and represent an anticipated aggregate investment of $661.1 million . At March 31, 2019 , development in progress totaled $440.6 million . In addition, as of March 31, 2019 , the Company had invested $9.1 million in deferred leasing costs related to these development buildings. The Company is currently developing two properties for its unconsolidated joint ventures which represent an anticipated aggregate investment by the joint ventures of $ 236.4 million . As of March 31, 2019, the Company was committed to the following: • $13.3 million in improvements on certain buildings and land parcels; • $44.5 million in future land acquisitions which it expects to complete during the year ending December 31, 2019; • up to $19.4 million of tenant improvements not yet completed; and • infrastructure improvements of $564,000 . 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. Two unconsolidated joint ventures in which the Company holds an interest have engaged the Company as the developer of the Comcast Technology Center (the “Project") pursuant to a Development Agreement by which the Company agrees, in consideration for a development fee, to be responsible for all aspects of the development of the Project and to guarantee the timely lien-free completion of construction of the Project as well as the payment, subject to certain exceptions, of any cost overruns incurred in the development of the Project. See Note 13 for details on the commitments and contingencies associated with the Project.

Supplemental Disclosure to Stat

Supplemental Disclosure to Statements of Cash Flows	3 Months Ended
	Mar. 31, 2019
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 three months ended March 31, 2019 and 2018 (amounts in thousands): 2019 2018 Write-off of fully depreciated/amortized property and deferred costs - properties included in continuing operations $ 1,105 $ 6,903 Write-off of fully depreciated/amortized property and deferred costs - properties included in discontinued operations $ — $ 6 Write-off of depreciated property and deferred costs due to sale - properties included in continuing operations $ — $ 3,045 Write-off of depreciated property and deferred costs due to sale - properties included in discontinued operations $ 12,049 $ 96,936 Changes in accrued development capital expenditures - properties included in continuing operations $ (1,981 ) $ 622 Changes in accrued development capital expenditures - properties included in discontinued operations $ (806 ) $ (2,664 ) Unrealized (loss) gain on cash flow hedge $ (1,854 ) $ 385 Capitalized equity-based compensation $ 436 $ 185 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. The following is a reconciliation of the Company's cash and cash equivalents and restricted cash at the beginning and end of the three months ended March 31, 2019 and 2018 (amounts in thousands): 2019 2018 Cash and cash equivalents at beginning of period $ 84,923 $ 11,882 Restricted cash at beginning of period 10,899 13,803 Cash and cash equivalents and restricted cash at beginning of period $ 95,822 $ 25,685 Cash and cash equivalents at end of period $ 96,949 $ 30,380 Restricted cash at end of period 17,696 9,366 Cash and cash equivalents and restricted cash at end of period $ 114,645 $ 39,746 Restricted cash includes tenant security deposits and escrow funds that the Company maintains pursuant to certain mortgage loans. Restricted cash also includes the undistributed proceeds from the sale of land in Kent County, United Kingdom.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Policy)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recently Issued Accounting Standards	Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”), which supersedes nearly all existing revenue recognition guidance (except revenue in the scope of other accounting standards, including standards related to leasing). Subsequently, the FASB issued supplementary standards providing additional guidance and targeted improvements to ASU 2014-09 (collectively, the “Revenue Standards”). The Revenue Standards provide a unified model to determine how revenue is recognized. In accordance with the Revenue Standards, the Company performs the following steps: (i) identify the contract with the customer, (ii) identify the performance obligations within the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations and (v) recognize revenue when (or as) a performance obligation is satisfied. Upon adoption of the Revenue Standards, the Company evaluated each of its revenue streams: lease agreement revenue, development service fee revenue, deferred land sale revenue and gain or loss on sale of nonfinancial assets. The Company concluded that there are no revenue streams from its lease agreements that are covered by the Revenue Standards with the possible exception of non-lease components as further discussed below. The Revenue Standards did not have an impact on the amount and timing of recognizing the Company's development service fee income. The Company recognizes development service fee income on a variable basis as a percentage of costs incurred on third party development contracts. Property development services, which are a single performance obligation, continue to be satisfied and recognized over time. The Company measures its progress toward completing the performance obligations under each arrangement. The measurement of the transfer of value to the customer for these services utilizes the input method (actual costs incurred against anticipated project costs) since this method best depicts the actual transfer of value promised to the customer. Estimated expected losses on such contracts are accrued in the period in which they are determinable. The total amount of consideration to be received from these projects is assessed on a quarterly basis. Based on existing contracts, completion is anticipated during 2019. The Company recognizes revenues from improving land sites and selling the underlying land on behalf of its development partner to home builders in the United Kingdom. These agreements contain a pre-emption clause and a seller's call option. The Company recognizes revenue as the pre-emption period or seller's call option lapses utilizing the output method. There was $3.7 million in revenue recognized for such contracts during the three months ended March 31, 2019. The Revenue Standards did not have an impact on the gain or loss on sale of nonfinancial assets. The Revenue Standards require the Company to derecognize nonfinancial assets once it transfers control of a distinct nonfinancial asset or distinct in-substance nonfinancial asset. Additionally, when the Company transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling ownership interest, the Company is required to measure any noncontrolling interest it receives or retains at fair value. The guidance requires companies to recognize a full gain or loss on the transaction. See Notes 5 and 7 for further discussion of sales of nonfinancial assets during the three months ended March 31, 2019. Estimated gross revenue related to the remaining performance obligations under existing contracts (before allocation of related costs and expenses) as of March 31, 2019 that will be recognized as revenue in future periods was approximately $34.2 million , which is expected to be recognized in 2019 through 2021. Recently Issued Accounting Standards Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update 2016-02, Leases (“ASU 2016-02”). Additional guidance and targeted improvements to ASU 2016-02 were made through the issuances of supplementary ASUs in July 2018, December 2018 and March 2019 (collectively, the "New Lease Standard"). The New Lease Standard sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). It requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. The New Lease Standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales type leases, direct financing leases and operating leases. The New Lease Standards limit capitalization of certain initial direct costs which were previously capitalizable under previous lease standards. Such costs which were expensed during the three months ended March 31, 2019 were $ 0.3 million . The Company adopted the New Lease Standard on January 1, 2019 and applied it using a modified retrospective approach whereby the cumulative effect of the adoption was recognized on the adoption date and prior periods were not restated. There was no net cumulative effect adjustment to retained earnings as of January 1, 2019 as a result of this adoption. The following practical expedients available for implementation were elected: a. whether an expired or existing contract meets the definition of a lease b. the lease classification at the adoption date for existing or expired leases c. whether costs previously capitalized as initial direct costs would continue to be amortized Additionally, the Company has elected the practical expedient not to recognize right of use assets and lease liabilities with a term of one year or less. The Company's leases met the criteria in the New Lease Standard to not separate non-lease components from the related lease component; therefore, the accounting for these leases remained largely unchanged from the previous standard. The Company has elected to exclude sales and other similar taxes from the measurement of lease revenue and expense and the Company has excluded those costs paid directly by lessees to third parties. Lessee Disclosure As of March 31, 2019, the Company had a total of five properties subject to operating ground leases in Florida, New Jersey, Kentucky and the United Kingdom with a weighted average remaining term of 47 years. These leases have remaining terms of 11 to 110 years, expiration dates of June 2030 to June 2129, and renewal options of 25 to 48 years. The Company has included in the lease terms renewal options to the useful life of the asset constructed on the land. Payments for certain properties are subject to increases at five -year intervals based upon the agreed or appraised fair market value of the leased premises on the adjustment date or the Consumer Price Index percentage increase since the base rent date. These future changes in payments are considered variable payments and do not impact the assessment of the asset or liability unless there is a significant event that triggers reassessment, such as an amendment with a change in the terms of the lease. The Company used discount rates in a range of 4.1% to 5.0% for a weighted average discount rate of 4.6% , which was derived from the Company's assessment of credit quality of the Company adjusted to reflect secured borrowing, estimated yield curves and long-term spread adjustments over appropriate tenors. The Company also leases office space from unrelated third-parties. The Company recognized $468,000 of lease expense, of which $433,000 was paid in cash, during the three months ended March 31, 2019. The following schedule indicates the approximate future minimum lease payments for the ground and office leases as of March 31, 2019: Year Amount 2019 (remainder of year) $ 1,134 2020 1,376 2021 1,235 2022 1,137 2023 1,036 Thereafter 40,842 Total minimum payments $ 46,760 Imputed interest (27,833 ) Amortization (175 ) Lease liabilities $ 18,752 Deferred rent (655 ) Right of use asset $ 18,097 As noted above, the Company adopted the New Lease Standard effective January 1, 2019. Since the Company has applied the provisions on a modified retrospective basis, the following represents approximate future minimum lease payments by year as of December 31, 2018, as applicable under ASC 840, Leases, prior to the adoption of the New Lease Standard. Year Amount 2019 $ 1,512 2020 1,356 2021 1,205 2022 1,082 2023 981 Thereafter 40,799 $ 46,935 The Company recorded ground lease expense of $1.5 million for the year ended December 31, 2018. Lessor Disclosures The Company leases its operating properties to customers under agreements that are classified as operating leases. It manages residual risk through investing in properties that it believes will appreciate in value over time. Substantially all of the Company's operating leases contain provisions for specified annual increases over the rents of the prior year. Rental income from operating leases is generally recognized on a straight-line basis over the lease term when the Company has determined that the collectibility of substantially all the lease payments is probable. If the Company determines that it is not probable that substantially all of the lease payments will be collected, the Company accounts for the revenue under the lease on a cash basis. Changes in the assessment of probability are accounted for on a cumulative basis as if the lease had always been accounted for based on the current determination of the likelihood of collection potentially resulting in increased volatility of rental revenue. Some of the Company's leases have options to extend, terminate or purchase the facilities, which are considered when determining the lease term. Tenant rights to purchase an underlying asset are at prevailing market rates at the time of purchase. The Company does not include in measurement of lease receivables certain variable payments, including changes in an index, until the specific events that trigger the variable payments have occurred. Generally operating leases require the tenants to reimburse the Company for property tax and other expenditures that are not considered components of the lease and therefore no consideration is allocated to them as they do not result in the transfer of a good or service to the tenants. The Company has determined that all of its leases qualify for the practical expedient to not separate the lease and non-lease components because (i) the lease components are operating leases and (ii) the timing and pattern of recognition of the non-lease components are the same as the lease components. The Company applies the New Lease Standard to the combined component. Income derived from the Company's leases is recorded in rental revenue in the Company's consolidated statement of comprehensive income. Certain tenants are obligated to pay directly their obligations under their leases for real estate taxes, insurance and certain other expenses. These obligations, which have been assumed by the tenants under the terms of their respective leases, are not reflected in the Company's consolidated financial statements. To the extent any tenant responsible for these obligations under the respective lease defaults on its lease or if it is deemed probable that the tenant will fail to pay for such costs, the Company would record a liability for such obligation. The following details the rental income and variable lease income for the three months ended March 31, 2019: For the Three Months Ended March 31, 2019 (in thousands) Rental income - operating leases - continuing operations $ 121,538 Rental income - operating leases - discontinued operations 10,204 Variable lease income - operating leases - continuing operations 35,348 Variable lease income - operating leases - discontinued operations 3,060 The following amounts reflect the estimated contractual rents due to the Company for the remainder of terms of the Company's operating leases as of March 31, 2019: (in thousands) Remainder of 2019 $ 384,744 2020 481,612 2021 412,630 2022 342,633 2023 279,153 2024 227,300 Thereafter 854,364 Total $ 2,982,436 Other In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities ("ASU 2017-12"). ASU 2017-12 is designed to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. The Company adopted ASU 2017-12 on January 1, 2019 and it did not have a material impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software: Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract ("ASU 2018-15"). ASU 2018-15 amends the definition of a hosting arrangement and requires a customer in a hosting arrangement that is a service contract to capitalize certain implementation costs as if the arrangement was an internal-use software project. ASU 2018-15 is effective for the Company beginning January 1, 2020. Upon adoption, the Company does not anticipate the impact of ASU 2018-15 will have a material impact on the consolidated financial statements.
Segment Reporting	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.
Discontinued Operations	The Company determined that the strategic shift would have a major effect on its operations and financial results. As such, properties sold or those that meet the criteria to be classified as held for sale within the corporate strategy were classified within discontinued operations. Consistent with the held for sale criteria these properties are expected to be sold within one year . As the result of the classification within discontinued operations, the in-service assets and liabilities of this portfolio are required to be presented as held for sale for all prior periods presented in our Consolidated Balance Sheets. Operating results pertaining to these properties were reclassified to discontinued operations for all prior periods presented in our Consolidated Statements of Comprehensive Income.
Fair Value of Financial Instruments	ASC 820, Fair Value Measurements and Disclosures , provides guidance on the fair value measurement of a financial asset or liability. Inputs used to develop fair value are classified in one of three categories: Level 1 inputs (quoted prices (unadjusted) in active markets for identical assets or liabilities), Level 2 inputs (inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly) and Level 3 inputs (unobservable inputs for the asset or liability). 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 December 31, 2018 and March 31, 2019 . 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 facilities 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 December 31, 2018 and March 31, 2019 . 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.

Organization and Basis of Pre_3

Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of future minimum rent payments	. The following schedule indicates the approximate future minimum lease payments for the ground and office leases as of March 31, 2019: Year Amount 2019 (remainder of year) $ 1,134 2020 1,376 2021 1,235 2022 1,137 2023 1,036 Thereafter 40,842 Total minimum payments $ 46,760 Imputed interest (27,833 ) Amortization (175 ) Lease liabilities $ 18,752 Deferred rent (655 ) Right of use asset $ 18,097
Future minimum rental payments	Since the Company has applied the provisions on a modified retrospective basis, the following represents approximate future minimum lease payments by year as of December 31, 2018, as applicable under ASC 840, Leases, prior to the adoption of the New Lease Standard. Year Amount 2019 $ 1,512 2020 1,356 2021 1,205 2022 1,082 2023 981 Thereafter 40,799 $ 46,935
Schedule of lease income	The following details the rental income and variable lease income for the three months ended March 31, 2019: For the Three Months Ended March 31, 2019 (in thousands) Rental income - operating leases - continuing operations $ 121,538 Rental income - operating leases - discontinued operations 10,204 Variable lease income - operating leases - continuing operations 35,348 Variable lease income - operating leases - discontinued operations 3,060
Schedule of lease payments receivable	The following amounts reflect the estimated contractual rents due to the Company for the remainder of terms of the Company's operating leases as of March 31, 2019: (in thousands) Remainder of 2019 $ 384,744 2020 481,612 2021 412,630 2022 342,633 2023 279,153 2024 227,300 Thereafter 854,364 Total $ 2,982,436

Income per Common Share of th_2

Income per Common Share of the Trust (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of earnings per share	The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): Three Months Ended Three Months Ended March 31, 2019 March 31, 2018 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 39,887 147,559 $ 0.27 $ 39,574 147,060 $ 0.27 Dilutive shares for long-term compensation plans — 981 — 813 Income from continuing operations net of noncontrolling interest - diluted $ 39,887 148,540 $ 0.27 $ 39,574 147,873 $ 0.27 Discontinued operations net of noncontrolling interest - basic $ 14,443 147,559 $ 0.10 $ 100,607 147,060 $ 0.68 Dilutive shares for long-term compensation plans — 981 — 813 Discontinued operations net of noncontrolling interest - diluted $ 14,443 148,540 $ 0.10 $ 100,607 147,873 $ 0.68 Net income available to common shareholders - basic $ 54,330 147,559 $ 0.37 $ 140,181 147,060 $ 0.95 Dilutive shares for long-term compensation plans — 981 — 813 Net income available to common shareholders - diluted $ 54,330 148,540 $ 0.37 $ 140,181 147,873 $ 0.95

Income per Common Unit of the_2

Income per Common Unit of the Operating Partnership (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Unit, Basic and Diluted [Line Items]
Schedule of earnings per share	The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): Three Months Ended Three Months Ended March 31, 2019 March 31, 2018 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 39,887 147,559 $ 0.27 $ 39,574 147,060 $ 0.27 Dilutive shares for long-term compensation plans — 981 — 813 Income from continuing operations net of noncontrolling interest - diluted $ 39,887 148,540 $ 0.27 $ 39,574 147,873 $ 0.27 Discontinued operations net of noncontrolling interest - basic $ 14,443 147,559 $ 0.10 $ 100,607 147,060 $ 0.68 Dilutive shares for long-term compensation plans — 981 — 813 Discontinued operations net of noncontrolling interest - diluted $ 14,443 148,540 $ 0.10 $ 100,607 147,873 $ 0.68 Net income available to common shareholders - basic $ 54,330 147,559 $ 0.37 $ 140,181 147,060 $ 0.95 Dilutive shares for long-term compensation plans — 981 — 813 Net income available to common shareholders - diluted $ 54,330 148,540 $ 0.37 $ 140,181 147,873 $ 0.95
Liberty Property Limited Partnership
Earnings Per Unit, Basic and Diluted [Line Items]
Schedule of earnings per share	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): Three Months Ended Three Months Ended March 31, 2019 March 31, 2018 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations - net of noncontrolling interest - consolidated joint ventures $ 40,918 $ 40,631 Less: Preferred unit distributions (84 ) (118 ) Income from continuing operations available to common unitholders - basic $ 40,834 151,079 $ 0.27 $ 40,513 150,580 $ 0.27 Dilutive units for long-term compensation plans — 981 — 813 Income from continuing operations available to common unitholders - diluted $ 40,834 152,060 $ 0.27 $ 40,513 151,393 $ 0.27 Income from discontinued operations - basic $ 14,786 151,079 $ 0.10 $ 103,007 150,580 $ 0.68 Dilutive units for long-term compensation plans — 981 — 813 Income from discontinued operations - diluted $ 14,786 152,060 $ 0.10 $ 103,007 151,393 $ 0.68 Income available to common unitholders - basic $ 55,620 151,079 $ 0.37 $ 143,520 150,580 $ 0.95 Dilutive units for long-term compensation plans — 981 — 813 Income available to common unitholders - diluted $ 55,620 152,060 $ 0.37 $ 143,520 151,393 $ 0.95

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of accumulated other comprehensive income	The following table sets forth the components of Accumulated Other Comprehensive Loss (in thousands): As of and for the three months ended March 31, 2019 2018 Foreign Currency Translation: Beginning balance $ (52,862 ) $ (38,701 ) Translation adjustment 5,376 7,932 Ending balance (47,486 ) (30,769 ) Derivative Instruments: Beginning balance (3,550 ) 150 Unrealized gain (1,830 ) 369 Reclassification adjustment (1) (24 ) 16 Ending balance (5,404 ) 535 Total accumulated other comprehensive loss (52,890 ) (30,234 ) Less: portion included in noncontrolling interest – operating partnership 1,087 560 Total accumulated other comprehensive loss included in shareholders' equity/owners' equity $ (51,803 ) $ (29,674 ) (1) Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate (Tables)

Real Estate (Tables)	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Schedule of operating properties and land parcels	Information on the Operating Properties and land parcels the Company acquired during the three months ended March 31, 2019 is as follows: Three Months Ended March 31, 2019 Number of Buildings Acres of Developable Land Leaseable Square Feet Purchase Price (in thousands) Dallas 2 — 509,733 $ 44,400 Southern California 1 — 289,683 31,285 United Kingdom — 25.0 — 2,658 Other: Atlanta — 154.7 — 5,000 New Jersey 2 — 270,254 51,775 5 179.7 1,069,670 $ 135,118 Information on the Operating Properties and land parcels the Company sold during the three months ended March 31, 2019 is as follows: Three Months Ended March 31, 2019 Number of Buildings Acres of Developable Land Leaseable Square Feet Gross Proceeds (in thousands) Florida 3 — 150,751 $ 23,400 Other New Jersey — 0.8 — 4,000 DC Metro 1 — 146,472 61,750 4 0.8 297,223 $ 89,150

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Schedule of operating information by reportable segment	The operating information by reportable segment is as follows (in thousands): Three Months Ended March 31, 2019 March 31, 2018 Revenue Carolinas/Richmond $ 20,086 $ 19,793 Chicago/Minneapolis 17,415 16,517 Cincinnati/Columbus/Indianapolis 4,341 4,822 Dallas 5,517 4,085 Florida 16,283 15,408 Houston 16,091 15,862 Lehigh/Central PA 40,208 38,085 Philadelphia 11,338 12,345 Southern California 9,551 6,795 United Kingdom 5,998 4,273 Other 23,552 34,103 Segment-level revenue 170,380 172,088 Reconciliation to total revenue Development service fee income 864 26,352 Discontinued operations (13,264 ) (25,631 ) Other (230 ) (96 ) Total revenue $ 157,750 $ 172,713 Net operating income Carolinas/Richmond $ 14,332 $ 14,047 Chicago/Minneapolis 10,335 9,901 Cincinnati/Columbus/Indianapolis 2,770 3,268 Dallas 3,390 2,473 Florida 11,436 10,819 Houston 8,865 9,597 Lehigh/Central PA 28,427 27,767 Philadelphia 8,075 10,154 Southern California 7,447 5,228 United Kingdom 2,981 2,429 Other 14,214 22,471 Net operating income 112,272 118,154 Reconciliation to income from continuing operations Interest expense (1) (26,205 ) (23,459 ) Depreciation/amortization expense (1) (2) (33,585 ) (33,408 ) Gain on property dispositions 741 4,158 Equity in earnings of unconsolidated joint ventures 7,009 6,764 General and administrative expense (1) (2) (13,158 ) (10,725 ) Leasing cost (3,208 ) (2,812 ) Other operating expenses (2) (2,268 ) (2,502 ) Discontinued operations excluding gain and impairment on property dispositions (6,119 ) (12,995 ) Income taxes (1) (2) (242 ) (12 ) Other 5,725 (2,445 ) Income from continuing operations $ 40,962 $ 40,718 (1) Includes activity in discontinued operations. (2) Excludes costs that are included in determining net operating income.
Schedule of total assets by reportable segments	The Company's total assets by reportable segment as of March 31, 2019 and December 31, 2018 is as follows (in thousands): March 31, 2019 December 31, 2018 Carolinas/Richmond $ 526,631 $ 525,041 Chicago/Minnesota 588,169 591,792 Cincinnati/Columbus/Indianapolis 132,501 131,400 Dallas 305,929 261,538 Florida 543,304 547,232 Houston 586,409 568,756 Lehigh/Central PA 1,208,754 1,210,220 Philadelphia 609,011 624,373 Southern California 703,117 660,688 United Kingdom 409,821 463,162 Other 1,152,581 1,153,518 Segment-level total assets 6,766,227 6,737,720 Corporate Other 172,352 196,672 Total assets $ 6,938,579 $ 6,934,392

Impairment and Disposal of Lo_2

Impairment and Disposal of Long-Lived Assets Impairment and Disposal of Long-Lived Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Schedule of disposal groups	The following table illustrates aggregate balance sheet information for all held for sale properties (in thousands): March 31, 2019 December 31, 2018 Included in Continuing Operations Included in Discontinued Operations Total Included in Continuing Operations Included in Discontinued Operations Total Land and land improvements $ 2,444 $ 88,251 $ 90,695 $ 1,301 $ 108,001 $ 109,302 Buildings and improvements 16,577 297,375 313,952 5,638 371,461 377,099 Land held for development 36,957 — 36,957 26,253 — 26,253 Accumulated depreciation (2,814 ) (45,440 ) (48,254 ) (1,546 ) (66,176 ) (67,722 ) Deferred financing and leasing costs, net 382 12,443 12,825 58 13,539 13,597 Other assets 796 16,875 17,671 164 19,023 19,187 Total assets held for sale $ 54,342 $ 369,504 $ 423,846 $ 31,868 $ 445,848 $ 477,716 Total liabilities held for sale $ 3,695 $ 14,340 $ 18,035 $ 141 $ 16,924 $ 17,065 The following table illustrates the number of sold or held for sale properties included in, or excluded from, discontinued operations: Held for Sale as of March 31, 2019 Sold during the three months ended March 31, 2019 Sold during the year ended December 31, 2018 Total Properties included in discontinued operations 16 4 37 57 Properties included in continuing operations 2 — 2 4 Properties sold or classified as held for sale 18 4 39 61 A summary of the results of operations for the properties classified as discontinued operations is as follows (in thousands): Three Months Ended March 31, 2019 March 31, 2018 Revenues $ 13,264 $ 25,631 Operating expenses (4,288 ) (6,572 ) Depreciation and amortization (1,981 ) (5,246 ) Impairment expense (10,274 ) — Interest and other income (158 ) (3 ) Income taxes (32 ) (26 ) Interest expense (686 ) (789 ) Gain on property dispositions 18,941 90,012 Income from discontinued operations 14,786 103,007 Noncontrolling interest - operating partnership (343 ) (2,400 ) Income from discontinued operations available to common shareholders $ 14,443 $ 100,607

Noncontrolling Interest - Ope_2

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Tables)	3 Months Ended
	Mar. 31, 2019
Temporary Equity [Line Items]
Schedule of preferred units	As of March 31, 2019 , 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 $ 5,337 213 $ 25 6.25 %

Disclosure of Fair Value of F_2

Disclosure of Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Instrument, Fair Value Disclosure [Abstract]
Schedule of fair value	The following summarizes the fair value of the Company's mortgage loans and unsecured notes as of December 31, 2018 and March 31, 2019 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2018 $ 395,202 $ 397,167 $ 2,285,698 $ 2,295,699 As of March 31, 2019 $ 396,690 $ 396,930 $ 2,632,089 $ 2,722,758

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of gains or losses recognized related to derivatives	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 months ended March 31, 2019 and 2018 (in thousands): Three Months Ended March 31, 2019 March 31, 2018 Amount of gain related to the effective portion recognized in other comprehensive (loss) income $ 559 $ 402 Total Amount of Interest Expense Presented in the Consolidated Statements of Comprehensive Income 25,519 22,670
Schedule of derivative instruments, classification on the accompanying balance sheets	The following table presents the fair value of the Company’s derivative financial instruments as well as their classification on the accompanying consolidated balance sheets as of March 31, 2019 and December 31, 2018 (amounts in thousands): Derivatives Fair Value at: Balance Sheet Location March 31, 2019 December 31, 2018 Derivatives designated as hedging instruments: Interest Rate Swaps Other Liabilities $ 591 $ 677 Interest Rate Treasury Locks Other Liabilities — 3,972 Total $ 591 $ 4,649

Supplemental Disclosure to St_2

Supplemental Disclosure to Statements of Cash Flows (Tables)	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Schedule of supplemental disclosure to statement of cash flows	The following is a reconciliation of the Company's cash and cash equivalents and restricted cash at the beginning and end of the three months ended March 31, 2019 and 2018 (amounts in thousands): 2019 2018 Cash and cash equivalents at beginning of period $ 84,923 $ 11,882 Restricted cash at beginning of period 10,899 13,803 Cash and cash equivalents and restricted cash at beginning of period $ 95,822 $ 25,685 Cash and cash equivalents at end of period $ 96,949 $ 30,380 Restricted cash at end of period 17,696 9,366 Cash and cash equivalents and restricted cash at end of period $ 114,645 $ 39,746 The following are supplemental disclosures to the consolidated statements of cash flows for the three months ended March 31, 2019 and 2018 (amounts in thousands): 2019 2018 Write-off of fully depreciated/amortized property and deferred costs - properties included in continuing operations $ 1,105 $ 6,903 Write-off of fully depreciated/amortized property and deferred costs - properties included in discontinued operations $ — $ 6 Write-off of depreciated property and deferred costs due to sale - properties included in continuing operations $ — $ 3,045 Write-off of depreciated property and deferred costs due to sale - properties included in discontinued operations $ 12,049 $ 96,936 Changes in accrued development capital expenditures - properties included in continuing operations $ (1,981 ) $ 622 Changes in accrued development capital expenditures - properties included in discontinued operations $ (806 ) $ (2,664 ) Unrealized (loss) gain on cash flow hedge $ (1,854 ) $ 385 Capitalized equity-based compensation $ 436 $ 185

Organization and Basis of Pre_4

Organization and Basis of Presentation - Organization (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Ownership interest in operating partnership - Limited Partnership	97.70%
Liberty Comcast 1701 JFK Boulevard, LP
Variable Interest Entity [Line Items]
Ownership percentage of equity method investment	20.00%
Liberty Comcast 1701 JFK Boulevard, LP | Variable Interest Entity, Not Primary Beneficiary | Other Investments
Variable Interest Entity [Line Items]
Equity investment in joint venture	$ 74.3	$ 75.1

Organization and Basis of Pre_5

Organization and Basis of Presentation - Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from improving land sites	$ 864	$ 26,352
Revenue from remaining performance obligation	34,200
United Kingdom
Disaggregation of Revenue [Line Items]
Revenue from improving land sites	$ 3,700

Organization and Basis of Pre_6

Organization and Basis of Presentation - Ground Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)properties	Mar. 31, 2018USD ($)
Lessee, Lease, Description [Line Items]
Leasing expense	$ 3,208	$ 2,812
Number of properties subject to ground lease (in properties) | properties	5
Weighted average remaining lease term	47 years
Term of contract	11 years
Useful life increase interval	5 years
Weighted average discount rate	4.60%
Leasing expense	$ 468
Cash portion of lease expense	$ 433
Minimum
Lessee, Lease, Description [Line Items]
Renewal term	25 years
Weighted average discount rate	4.10%
Maximum
Lessee, Lease, Description [Line Items]
Term of contract	110 years
Renewal term	48 years
Weighted average discount rate	5.00%
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Leasing expense	$ 300

Organization and Basis of Pre_7

Organization and Basis of Presentation - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Mar. 31, 2019
Ground Leases Disclosures [Abstract]
2019 (remainder of year)		$ 1,134
2020		1,376
2021		1,235
2022		1,137
2023		1,036
Thereafter		40,842
Total minimum payments		46,760
Imputed interest		(27,833)
Amortization		(175)
Lease liabilities	$ 0	18,752
Deferred rent		(655)
Right of use asset	0	18,097
Leases, Operating [Abstract]
2019	1,512
2020	1,356
2021	1,205
2022	1,082
2023	981
Thereafter	40,799
Future minimum payments due	46,935
Rent expense	$ 1,500
Operating Leases Receivable
Remainder of 2019		384,744
2020		481,612
2021		412,630
2022		342,633
2023		279,153
2024		227,300
Thereafter		854,364
Total		$ 2,982,436

Organization and Basis of Pre_8

Organization and Basis of Presentation - Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Rental income - operating leases - continuing operations	$ 121,538
Rental income - operating leases - discontinued operations	10,204
Variable lease income - operating leases - continuing operations	35,348
Variable lease income - operating leases - discontinued operations	$ 3,060

Income per Common Share of th_3

Income per Common Share of the Trust (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest	$ 39,887	$ 39,574
Income from discontinued operations net of noncontrolling interest	14,443	100,607
Net income available to common shareholders	$ 54,330	$ 140,181
Weighted Average Shares (Denominator) [Abstract]
Income from continuing operations net of noncontrolling interest - basic, weighted average shares (in shares)	147,559	147,060
Dilutive shares for long-term compensation plans, weighted average shares (in shares)	981	813
Income from continuing operations net of noncontrolling interest - diluted, weighted average shares (in shares)	148,540	147,873
Common shares
Earnings Per Share, Basic [Abstract]
Income from continuing operations (in usd per share)	$ 0.27	$ 0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - basic (in usd per share)	0.37	0.95
Earnings Per Share, Diluted [Abstract]
Income from continuing operations (in usd per share)	0.27	0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - diluted (in usd per share)	$ 0.37	$ 0.95

Income per Common Share of th_4

Income per Common Share of the Trust Income per Common Share of the Trust - Anti-dilutive Options (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Stock Option
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive options excluded from computation of earnings per share	0	0

Income per Common Share of th_5

Income per Common Share of the Trust - Options Exercised (Details) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Stock Option | Common shares
Stock Option Exercises [Line Items]
Amount of options exercised in period	109,000	151,000

Income per Common Share of th_6

Income per Common Share of the Trust - Share Repurchase (Details) - 2017 Share Repurchase Program - Common shares - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount	$ 250
Stock repurchased in period (in shares)	0	0

Income per Common Unit of the_3

Income per Common Unit of the Operating Partnership - Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$ 39,887	$ 39,574
Income from discontinued operations	14,786	103,007
Net income available to common shareholders	$ 54,330	$ 140,181
Weighted Average Units (Denominator) [Abstract]
Income from continuing operations net of noncontrolling interest - basic, weighted average shares (in shares)	147,559	147,060
Dilutive units for long-term compensation plans	981	813
Income from continuing operations net of noncontrolling interest - diluted, weighted average shares (in shares)	148,540	147,873
Liberty Property Limited Partnership
Income (Numerator) [Abstract]
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$ 40,918	$ 40,631
Income from continuing operations available to common unitholders	40,834	40,513
Income from discontinued operations	14,786	103,007
Net income available to common shareholders	$ 55,620	$ 143,520
Weighted Average Units (Denominator) [Abstract]
Income from continuing operations net of noncontrolling interest - basic, weighted average shares (in shares)	151,079	150,580
Dilutive units for long-term compensation plans	981	813
Income from continuing operations net of noncontrolling interest - diluted, weighted average shares (in shares)	152,060	151,393
Liberty Property Limited Partnership | Common Units
Earnings Per Unit, Basic [Abstract]
Income from continuing operations (in usd per share)	$ 0.27	$ 0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - basic (in usd per share)	0.37	0.95
Earnings Per Unit, Diluted [Abstract]
Income from continuing operations (in usd per share)	0.27	0.27
Income from discontinued operations (in usd per share)	0.10	0.68
Income per common share or unit - diluted (in usd per share)	$ 0.37	$ 0.95

Income per Common Unit of the_4

Income per Common Unit of the Operating Partnership - Anti-dilutive Options (Details) - Stock Option - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive options excluded from computation of earnings per share	0	0
Liberty Property Limited Partnership
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive options excluded from computation of earnings per share	0	0

Income per Common Unit of the_5

Income per Common Unit of the Operations Partnership - Options Exercised (Details) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Liberty Property Limited Partnership | Stock Option | Common Units
Stock Option Exercises [Line Items]
Amount of options exercised in period	109,000	151,000

Income per Common Unit of the_6

Income per Common Unit of the Operating Partnership Unit Repurchase (Details) - Liberty Property Limited Partnership - 2017 Share Repurchase Program - Common Units - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount	$ 250
Stock repurchased in period (in shares)	0	0

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 3,396,772	$ 3,148,366
Ending balance	3,398,813	3,248,288
Total accumulated other comprehensive loss	3,396,772	3,148,366	$ 3,398,813	$ 3,396,772	$ 3,248,288
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity			3,332,849	3,329,861
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(52,862)	(38,701)
Unrealized income (loss)	5,376	7,932
Ending balance	(47,486)	(30,769)
Total accumulated other comprehensive loss	(52,862)	(38,701)	(47,486)	(52,862)	(30,769)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(3,550)	150
Unrealized income (loss)	(1,830)	369
Reclassification adjustment	(24)	16
Ending balance	(5,404)	535
Total accumulated other comprehensive loss	(3,550)	150	(5,404)	(3,550)	535
AOCI Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending balance	(52,890)	(30,234)
Total accumulated other comprehensive loss	(52,890)	(30,234)	(52,890)		(30,234)
AOCI Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending balance	1,087	560
Total accumulated other comprehensive loss	1,087	560	1,087		560
AOCI Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(55,243)	(37,797)
Ending balance	(51,803)	(29,674)
Total accumulated other comprehensive loss	$ (55,243)	$ (37,797)	(51,803)	$ (55,243)	(29,674)
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity			$ (51,803)		$ (29,674)

Real Estate (Details)

Real Estate (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)ft²abldg
Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	5
Leaseable Square Feet (in sqft) | ft²	1,069,670
Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	179.7
Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Purchase Price (in thousands) | $	$ 135,118
Dallas | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	2
Leaseable Square Feet (in sqft) | ft²	509,733
Dallas | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0
Dallas | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Purchase Price (in thousands) | $	$ 44,400
Southern California | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	1
Leaseable Square Feet (in sqft) | ft²	289,683
Southern California | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0
Southern California | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Purchase Price (in thousands) | $	$ 31,285
United Kingdom | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	0
Leaseable Square Feet (in sqft) | ft²	0
United Kingdom | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	25
United Kingdom | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Purchase Price (in thousands) | $	$ 2,658
Atlanta | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	0
Leaseable Square Feet (in sqft) | ft²	0
Atlanta | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	154.7
Atlanta | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Purchase Price (in thousands) | $	$ 5,000
New Jersey | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	2
Leaseable Square Feet (in sqft) | ft²	270,254
New Jersey | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0
New Jersey | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Purchase Price (in thousands) | $	$ 51,775
Disposal Group, Not Discontinued Operations | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	4
Leaseable Square Feet (in sqft) | ft²	297,223
Disposal Group, Not Discontinued Operations | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0.8
Disposal Group, Not Discontinued Operations | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Gross Proceeds (in thousands) | $	$ 89,150
Disposal Group, Not Discontinued Operations | Florida | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	3
Leaseable Square Feet (in sqft) | ft²	150,751
Disposal Group, Not Discontinued Operations | Florida | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0
Disposal Group, Not Discontinued Operations | Florida | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Gross Proceeds (in thousands) | $	$ 23,400
Disposal Group, Not Discontinued Operations | New Jersey | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	0
Leaseable Square Feet (in sqft) | ft²	0
Disposal Group, Not Discontinued Operations | New Jersey | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0.8
Disposal Group, Not Discontinued Operations | New Jersey | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Gross Proceeds (in thousands) | $	$ 4,000
Disposal Group, Not Discontinued Operations | DC Metro | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Number of buildings (in buildings) | bldg	1
Leaseable Square Feet (in sqft) | ft²	146,472
Disposal Group, Not Discontinued Operations | DC Metro | Acres of Developable Land
Property, Plant and Equipment [Line Items]
Acres of Developable Land (in acres) | a	0
Disposal Group, Not Discontinued Operations | DC Metro | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Gross Proceeds (in thousands) | $	$ 61,750

Segment Information - Income St

Segment Information - Income Statement (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 157,750,000	$ 172,713,000
Interest expense	(25,519,000)	(22,670,000)
Depreciation and amortization expense	(43,484,000)	(39,659,000)
Gain on property dispositions	741,000	4,158,000
Equity in earnings of unconsolidated joint ventures	7,009,000	6,764,000
General and administrative expense	(15,607,000)	(14,335,000)
Leasing cost	3,208,000	2,812,000
Other operating expense	2,268,000	2,502,000
Income taxes	(832,000)	(528,000)
Income from continuing operations	40,962,000	40,718,000
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	0	0
Operating Segments
Segment Reporting Information [Line Items]
Revenue	170,380,000	172,088,000
Net operating income	112,272,000	118,154,000
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Revenue	(230,000)	(96,000)
Interest expense	(26,205,000)	(23,459,000)
Depreciation and amortization expense	(33,585,000)	(33,408,000)
Equity in earnings of unconsolidated joint ventures	7,009,000	6,764,000
General and administrative expense	(13,158,000)	(10,725,000)
Leasing cost	(3,208,000)	(2,812,000)
Other operating expense	(2,268,000)	(2,502,000)
Discontinued operations excluding (loss) gain on property dispositions	(6,119,000)	(12,995,000)
Income taxes	(242,000)	(12,000)
Other	5,725,000	(2,445,000)
Development service fee income | Segment Reconciling Items
Segment Reporting Information [Line Items]
Revenue	864,000	26,352,000
Discontinued operations | Segment Reconciling Items
Segment Reporting Information [Line Items]
Revenue	(13,264,000)	(25,631,000)
Carolinas/Richmond | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	20,086,000	19,793,000
Net operating income	14,332,000	14,047,000
Chicago/Minneapolis | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	17,415,000	16,517,000
Net operating income	10,335,000	9,901,000
Cincinnati/Columbus/Indianapolis | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	4,341,000	4,822,000
Net operating income	2,770,000	3,268,000
Dallas | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	5,517,000	4,085,000
Net operating income	3,390,000	2,473,000
Florida | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	16,283,000	15,408,000
Net operating income	11,436,000	10,819,000
Houston | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	16,091,000	15,862,000
Net operating income	8,865,000	9,597,000
Lehigh/Central PA | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	40,208,000	38,085,000
Net operating income	28,427,000	27,767,000
Philadelphia | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	11,338,000	12,345,000
Net operating income	8,075,000	10,154,000
Southern California | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	9,551,000	6,795,000
Net operating income	7,447,000	5,228,000
United Kingdom | Operating Segments | United Kingdom
Segment Reporting Information [Line Items]
Revenue	5,998,000	4,273,000
Net operating income	2,981,000	2,429,000
Other | Operating Segments
Segment Reporting Information [Line Items]
Revenue	23,552,000	34,103,000
Net operating income	$ 14,214,000	$ 22,471,000

Segment Information - Total Ass

Segment Information - Total Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Assets	$ 6,938,579	$ 6,934,392
Operating Segments
Segment Reporting Information [Line Items]
Assets	6,766,227	6,737,720
Operating Segments | Other
Segment Reporting Information [Line Items]
Assets	1,152,581	1,153,518
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Assets	172,352	196,672
North America | Operating Segments | Carolinas/Richmond
Segment Reporting Information [Line Items]
Assets	526,631	525,041
North America | Operating Segments | Chicago/Minneapolis
Segment Reporting Information [Line Items]
Assets	588,169	591,792
North America | Operating Segments | Cincinnati/Columbus/Indianapolis
Segment Reporting Information [Line Items]
Assets	132,501	131,400
North America | Operating Segments | Dallas
Segment Reporting Information [Line Items]
Assets	305,929	261,538
North America | Operating Segments | Florida
Segment Reporting Information [Line Items]
Assets	543,304	547,232
North America | Operating Segments | Houston
Segment Reporting Information [Line Items]
Assets	586,409	568,756
North America | Operating Segments | Lehigh/Central PA
Segment Reporting Information [Line Items]
Assets	1,208,754	1,210,220
North America | Operating Segments | Philadelphia
Segment Reporting Information [Line Items]
Assets	609,011	624,373
North America | Operating Segments | Southern California
Segment Reporting Information [Line Items]
Assets	703,117	660,688
United Kingdom | Operating Segments | United Kingdom
Segment Reporting Information [Line Items]
Assets	$ 409,821	$ 463,162

Impairment and Disposal of Lo_3

Impairment and Disposal of Long-Lived Assets - Discontinued Operations (Details)	3 Months Ended
	Mar. 31, 2019USD ($)bldg	Mar. 31, 2018USD ($)	Dec. 31, 2018bldg
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income taxes	$ (832,000)	$ (528,000)
Gain on property dispositions	8,700,000	90,000,000
Income from discontinued operations	14,786,000	103,007,000
Income from discontinued operations available to common shareholders	14,443,000	100,607,000
Discontinued operations
Discontined Operations Income Statement [Line Items]
Capital expenditures	1,500,000	16,200,000
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	13,264,000	25,631,000
Operating expenses	(4,288,000)	(6,572,000)
Depreciation and amortization	(1,981,000)	(5,246,000)
Impairment expense	(10,274,000)	0
Interest and other income	(158,000)	(3,000)
Income taxes	(32,000)	(26,000)
Interest expense	(686,000)	(789,000)
Gain on property dispositions	18,941,000	90,012,000
Income from discontinued operations	14,786,000	103,007,000
Noncontrolling interest - operating partnership	(343,000)	(2,400,000)
Income from discontinued operations available to common shareholders	$ 14,443,000	$ 100,607,000
Properties included in discontinued operations, held for sale
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	16
Properties included in discontinued operations, held for sale | Southeastern PA
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	5
Properties included in discontinued operations, held for sale | Chicago/Minneapolis
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	1
Properties included in discontinued operations, held for sale | Philadelphia
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	9
Properties included in discontinued operations, held for sale | DC Metro
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	1
Properties included in discontinued operations, sold
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	4		37
Properties included in discontinued operations, total
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	57
Properties included in continuing operations, held for sale
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	2
Properties included in continuing operations, sold
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	0		2
Properties included in continuing operations, total
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	4
Properties sold or classified as held for sale, held for sale
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	18
Properties sold or classified as held for sale, sold
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	4		39
Properties sold or classified as held for sale, total
Discontined Operations Income Statement [Line Items]
Number of buildings (in buildings) | bldg	61

Impairment and Disposal of Lo_4

Impairment and Disposal of Long-Lived Assets - Assets Held for Sale (Details) $ in Thousands	Mar. 31, 2019USD ($)bldg	Dec. 31, 2018USD ($)
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Total assets held for sale	$ 423,846	$ 477,716
Liabilities held for sale	$ 18,035	17,065
Included in Continuing Operations
Balance Sheet Disclosures by Disposal Groups [Line Items]
Number of buildings (in buildings) | bldg	2
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Land and land improvements	$ 2,444	1,301
Buildings and improvements	16,577	5,638
Land held for development	36,957	26,253
Accumulated depreciation	(2,814)	(1,546)
Deferred financing and leasing costs, net	382	58
Other assets	796	164
Total assets held for sale	54,342	31,868
Liabilities held for sale	$ 3,695	141
Included in Discontinued Operations
Balance Sheet Disclosures by Disposal Groups [Line Items]
Number of buildings (in buildings) | bldg	16
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Land and land improvements	$ 88,251	108,001
Buildings and improvements	297,375	371,461
Land held for development	0	0
Accumulated depreciation	(45,440)	(66,176)
Deferred financing and leasing costs, net	12,443	13,539
Other assets	16,875	19,023
Total assets held for sale	369,504	445,848
Liabilities held for sale	$ 14,340	16,924
Total
Balance Sheet Disclosures by Disposal Groups [Line Items]
Number of buildings (in buildings) | bldg	18
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Land and land improvements	$ 90,695	109,302
Buildings and improvements	313,952	377,099
Land held for development	36,957	26,253
Accumulated depreciation	(48,254)	(67,722)
Deferred financing and leasing costs, net	12,825	13,597
Other assets	17,671	19,187
Total assets held for sale	423,846	477,716
Liabilities held for sale	$ 18,035	$ 17,065

Impairment and Disposal of Lo_5

Impairment and Disposal of Long-Lived Assets - Impairment Charges - Real Estate Assets (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges	$ 10,400,000
Impairment charges - real estate assets	99,000	$ 0
Valuation adjustment	0
Office Building | DC Metro
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges - real estate assets	10,300,000
Land | Houston
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges - real estate assets	$ 99,000

Noncontrolling Interests of t_2

Noncontrolling Interests of the Trust- Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Redeemable Noncontrolling Interest [Line Items]
Limited Partners' common units outstanding	3,520,205	3,520,205
Liberty Property Limited Partnership
Redeemable Noncontrolling Interest [Line Items]
Limited Partners' common units outstanding	3,520,205	3,520,205
Market value of common units based on closing price	$ 170.4

Limited Partners' Equity and _2

Limited Partners' Equity and Noncontrolling Interest of the Operating Partnership (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Limited Partners' Capital Account [Line Items]
Limited Partners' common units outstanding	3,520,205	3,520,205
Liberty Property Limited Partnership
Limited Partners' Capital Account [Line Items]
Limited Partners' common units outstanding	3,520,205	3,520,205
Market value of common units based on closing price	$ 170.4

Noncontrolling Interest - Ope_3

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Temporary Equity [Line Items]
AMOUNT	$ 5,337	$ 7,537	$ 7,537	$ 7,537
Preferred units redeemed (in shares)	88,000
Preferred units redeemed, value	$ 2,200
Series I-2
Temporary Equity [Line Items]
UNITS	213,483	301,483
LIQUIDATION PREFERENCE (in usd per share)	$ 25
DIVIDEND RATE	6.25%

Indebtedness (Details)

Indebtedness (Details) - 4.375% Senior Unsecured Notes	Jan. 31, 2019USD ($)
Debt Instrument [Line Items]
Debt issued, face amount	$ 350,000,000
Debt instrument, stated percentage	4.375%

Disclosure of Fair Value of F_3

Disclosure of Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Mortgage Loans | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 396,690	$ 395,202
Mortgage Loans | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	396,930	397,167
Unsecured Notes | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	2,632,089	2,285,698
Unsecured Notes | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 2,722,758	$ 2,295,699

Unconsolidated Joint Ventures -

Unconsolidated Joint Ventures - Liberty Property 18th & Arch LP and Liberty Property 18th & Arch, Hotel, LP (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)ft²investment	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Jun. 30, 2014ft²roomstoryinvestment
Schedule of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated joint ventures	$ 353,215		$ 350,981
Building and Building Improvements
Schedule of Equity Method Investments [Line Items]
Leaseable square feet (in sqft) | ft²	1,069,670
Philadelphia | Liberty Property 18th & Arch
Schedule of Equity Method Investments [Line Items]
Number of equity method investments (in investments) | investment	2			2
Anticipated Aggregate Investment	$ 962,000
Investments in and advances to unconsolidated joint ventures	193,000
Philadelphia | Construction in Progress | Liberty Property 18th & Arch
Schedule of Equity Method Investments [Line Items]
Number of stories in a high-rise building (in stories) | story				60
Number of hotel rooms (in rooms) | room				219
Leaseable square feet (in sqft) | ft²				1,300,000
Philadelphia | Building and Building Improvements | Liberty Property 18th & Arch
Schedule of Equity Method Investments [Line Items]
Anticipated Aggregate Investment	226,100
Other Liabilities | Philadelphia | Liberty Property 18th & Arch | Guarantee Obligations
Schedule of Equity Method Investments [Line Items]
Loss contingency accrual	44,500		$ 67,300
Equity Method Investee | Liberty Property 18th & Arch | Philadelphia
Schedule of Equity Method Investments [Line Items]
Net operating income	$ 0	$ (1,800)

Unconsolidated Joint Ventures_2

Unconsolidated Joint Ventures - Cambridge Medipark Ltd (Details) - Cambridge Medipark Ltd - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule of Equity Method Investments [Line Items]
Ownership percentage of equity method investment	50.00%	50.00%
Leaseholds and Leasehold Improvements | Other Income | Disposal Group, Not Discontinued Operations
Schedule of Equity Method Investments [Line Items]
Gain on sale of leasehold interests	$ 775	$ 2,000

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2019USD ($)	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)contract
Derivative Instruments, Gain (Loss) [Line Items]
Total Amount of Interest Expense Presented in the Consolidated Statements of Comprehensive Income		$ 25,519	$ 22,670
Interest Rate Derivatives [Abstract]
Number of interest rate swaps		2
Fair value		$ 591		$ 4,649
Reclassification during next 12 months		200
Termination value		700
Interest Rate Swap
Interest Rate Derivatives [Abstract]
Aggregate notional amount		66,300		$ 66,800
Interest Rate Swap | Other Comprehensive Income (Loss) | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain related to the effective portion recognized in other comprehensive (loss) income		559	402
Interest Rate Swap | Interest Expense | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Amount of loss related to the effective portion subsequently reclassified to interest expense		24	$ 16
Interest Rate Lock Commitments
Interest Rate Derivatives [Abstract]
Number of interest rate swaps | contract				2
Aggregate notional amount				$ 200,000
Interest Rate Lock Agreement A
Interest Rate Derivatives [Abstract]
Aggregate notional amount				100,000
Derivative, gain on derivative				$ 2,400
Number of derivative instruments expired | contract				1
Interest Rate Lock Agreement B
Interest Rate Derivatives [Abstract]
Aggregate notional amount	$ 100,000
Gain (loss) on contract termination	$ 3,300
Other Liabilities | Interest Rate Swap
Interest Rate Derivatives [Abstract]
Fair value		591		$ 677
Other Liabilities | Interest Rate Lock Commitments
Interest Rate Derivatives [Abstract]
Fair value		$ 0		$ 3,972

Commitments and Contingencies -

Commitments and Contingencies - Legal Matters (Details)	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Number of legal claims	0

Commitments and Contingencies_2

Commitments and Contingencies - Other (Details)	Mar. 31, 2019USD ($)ft²propertiesbldginvestment	Dec. 31, 2018USD ($)	Jun. 30, 2014ft²investment
Loss Contingencies [Line Items]
Letters of credit outstanding	$ 8,300,000
Development in progress	440,593,000	$ 472,169,000
Acres of developable land | Land Purchases
Loss Contingencies [Line Items]
Remaining amount committed to future acquisitions	$ 44,500,000
Building and Building Improvements
Loss Contingencies [Line Items]
Leaseable square feet (in sqft) | ft²	1,069,670
Number of buildings (in buildings) | bldg	5
Supply Commitment | Leasehold Improvements
Loss Contingencies [Line Items]
Remaining maximum amount committed for tenant improvements	$ 19,400,000
Supply Commitment | Construction in Progress
Loss Contingencies [Line Items]
Leaseable square feet (in sqft) | ft²	7,500,000
Number of buildings (in buildings) | bldg	25
Total anticipated development cost	$ 661,100,000
Deferred leasing costs in development	$ 9,100,000
Supply Commitment | Construction in Progress | Equity Method Investments
Loss Contingencies [Line Items]
Number of buildings (in buildings) | properties	2
Remaining amount committed or obligated to pay	$ 564,000
Supply Commitment | Land, Buildings and Improvements
Loss Contingencies [Line Items]
Remaining amount committed or obligated to pay	$ 13,300,000
Philadelphia | Liberty Property 18th & Arch
Loss Contingencies [Line Items]
Number of equity method investments (in investments) | investment	2		2
Total anticipated development cost	$ 962,000,000
Philadelphia | Liberty Property 18th & Arch | Construction in Progress
Loss Contingencies [Line Items]
Leaseable square feet (in sqft) | ft²			1,300,000
Philadelphia | Liberty Property 18th & Arch | Building and Building Improvements
Loss Contingencies [Line Items]
Total anticipated development cost	226,100,000
American Water Works, Inc | Supply Commitment | Building and Building Improvements
Loss Contingencies [Line Items]
Other commitment	$ 236,400,000

Supplemental Disclosure to St_3

Supplemental Disclosure to Statements of Cash Flows - Schedule of Supplemental Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Continuing Operations
Other Significant Noncash Transactions [Line Items]
Write off of fully depreciated property and deferred costs	$ 1,105	$ 6,903
Write of depreciated property and deferred costs due to sale/demolition	0	3,045
Change in accrued development capital expenditures	(1,981)	622
Unrealized gain (loss) on cash flow hedge, non cash transaction	(1,854)	385
Capitalized equity-based compensation	436	185
Discontinued operations
Other Significant Noncash Transactions [Line Items]
Write off of fully depreciated property and deferred costs	0	6
Write of depreciated property and deferred costs due to sale/demolition	12,049	96,936
Change in accrued development capital expenditures	$ (806)	$ (2,664)

Supplemental Disclosure to St_4

Supplemental Disclosure to Statements of Cash Flows - Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash and cash equivalents	$ 96,949	$ 84,923	$ 30,380	$ 11,882
Restricted cash	17,696	10,899	9,366	13,803
Cash, cash equivalents and restricted cash	$ 114,645	$ 95,822	$ 39,746	$ 25,685