Liberty Property Trust (LPT) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Feb. 26, 2018	Jun. 30, 2017
Document Information [Line Items]
Entity Registrant Name	LIBERTY PROPERTY TRUST
Entity Central Index Key	921,112
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		147,460,813
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Public Float			$ 5.9
Liberty Property Limited Partnership [Member]
Document Information [Line Items]
Entity Registrant Name	LIBERTY PROPERTY LIMITED PARTNERSHIP
Entity Central Index Key	921,113

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Real estate:
Land and land improvements	$ 1,153,680	$ 1,060,065
Building and improvements	4,443,583	4,298,012
Less accumulated depreciation	(940,613)	(847,106)
Operating real estate	4,656,650	4,510,971
Development in progress	378,472	267,450
Land held for development	330,748	336,569
Net real estate	5,365,870	5,114,990
Cash and cash equivalents	11,882	43,642
Restricted cash	13,803	12,383
Accounts receivable, net	11,230	13,365
Deferred rent receivable, net	115,141	102,878
Deferred financing and leasing costs, net	159,250	147,038
Investments in and advances to unconsolidated joint ventures	288,456	245,078
Assets held for sale	182,228	164,888
Prepaid expenses and other assets	291,897	148,551
Total assets	6,439,757	5,992,813
LIABILITIES
Mortgage loans, net	267,093	276,650
Unsecured notes, net	2,283,513	2,280,286
Credit facilities	358,939	0
Accounts payable	79,605	64,951
Accrued interest	21,796	21,878
Dividend and distributions payable	60,330	71,501
Other liabilities	208,027	199,008
Liabilities held for sale	4,551	8,079
Total liabilities	3,283,854	2,922,353
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of December 31, 2017 and December 31, 2016	7,537	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 147,450,691 and 146,993,018 shares issued and outstanding as of December 31, 2017 and December 31, 2016, respectively	147	147
Additional paid-in capital	3,674,978	3,655,910
Accumulated other comprehensive loss	(37,797)	(56,031)
Distributions in excess of net income	(549,970)	(596,635)
Total Liberty Property Trust shareholders’ equity	3,087,358	3,003,391
Noncontrolling interest – operating partnership
3,520,205 and 3,530,031 common units outstanding as of December 31, 2017 and December 31, 2016, respectively	56,159	54,631
Noncontrolling interest – consolidated joint ventures	4,849	4,901
Total equity	3,148,366	3,062,923
Total liabilities, noncontrolling interest - operating partnership and equity	6,439,757	5,992,813
Liberty Property Limited Partnership [Member]
Real estate:
Land and land improvements	1,153,680	1,060,065
Building and improvements	4,443,583	4,298,012
Less accumulated depreciation	(940,613)	(847,106)
Operating real estate	4,656,650	4,510,971
Development in progress	378,472	267,450
Land held for development	330,748	336,569
Net real estate	5,365,870	5,114,990
Cash and cash equivalents	11,882	43,642
Restricted cash	13,803	12,383
Accounts receivable, net	11,230	13,365
Deferred rent receivable, net	115,141	102,878
Deferred financing and leasing costs, net	159,250	147,038
Investments in and advances to unconsolidated joint ventures	288,456	245,078
Assets held for sale	182,228	164,888
Prepaid expenses and other assets	291,897	148,551
Total assets	6,439,757	5,992,813
LIABILITIES
Mortgage loans, net	267,093	276,650
Unsecured notes, net	2,283,513	2,280,286
Credit facilities	358,939	0
Accounts payable	79,605	64,951
Accrued interest	21,796	21,878
Dividend and distributions payable	60,330	71,501
Other liabilities	208,027	199,008
Liabilities held for sale	4,551	8,079
Total liabilities	3,283,854	2,922,353
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of December 31, 2017 and December 31, 2016	7,537	7,537
EQUITY
General partner’s equity - 147,450,691 and 146,993,018 common units outstanding as of December 31, 2017 and December 31, 2016, respectively	3,087,358	3,003,391
Limited partners’ equity – 3,520,205 and 3,530,031 common units outstanding as of December 31, 2017 and December 31, 2016, respectively	56,159	54,631
Noncontrolling interest – operating partnership
Noncontrolling interest – consolidated joint ventures	4,849	4,901
Total equity	3,148,366	3,062,923
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,439,757	$ 5,992,813

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Par value (USD per share)	$ 0.001	$ 0.001
Common shares authorized	283,987,000	283,987,000
Common shares issued	147,450,691	146,993,018
Common shares outstanding	147,450,691	146,993,018
Redeemable Preferred Stock [Member]
Redeemable stock, preferred units outstanding	301,483	301,483
Liberty Property Limited Partnership [Member]
Common shares outstanding	147,450,691	146,993,018
Common units outstanding	3,520,205	3,530,031
Liberty Property Limited Partnership [Member] | Redeemable Preferred Stock [Member]
Redeemable stock, preferred units outstanding	301,483	301,483

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING REVENUE
Rental		$ 486,195	$ 519,368	$ 561,434
Operating expense reimbursement		150,910	178,389	212,526
Development service fee income	[1]	82,673	12,941	0
Total operating revenue		719,778	710,698	773,960
OPERATING EXPENSE
Rental property		66,018	94,177	123,997
Real estate taxes		90,187	95,202	101,647
General and administrative		56,975	67,088	68,264
Expensed pursuit costs		5,066	1,016	605
Depreciation and amortization		175,137	196,705	217,864
Development service fee expense		85,805	12,165	0
Impairment - real estate assets		3,946	3,879	17,215
Total operating expense		483,134	470,232	529,592
Operating income		236,644	240,466	244,368
OTHER INCOME (EXPENSE)
Interest and other income		7,778	13,817	23,758
Loss on debt extinguishment		(49)	(27,099)	0
Interest expense		(88,857)	(112,299)	(133,557)
Total other income (expense)		(81,128)	(125,581)	(109,799)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures		155,516	114,885	134,569
Gain on property dispositions		100,387	219,270	100,314
Income taxes		(1,992)	(1,971)	(2,673)
Equity in earnings of unconsolidated joint ventures		17,155	21,970	3,149
Income from continuing operations		271,066	354,154	235,359
Discontinued operations (including net gain on property dispositions of $14,578 for the year ended December 31, 2017)		18,979	11,991	10,565
Net income		290,045	366,145	245,924
Noncontrolling interest – operating partnership		(7,224)	(9,070)	(6,192)
Noncontrolling interest – consolidated joint ventures		(481)	(258)	(249)
Income available to common shareholders		282,340	356,817	239,483
Comprehensive income attributable to common shareholders
Net income		290,045	366,145	245,924
Other comprehensive income (loss) - foreign currency translation		18,066	(34,744)	(12,540)
Other comprehensive income (loss) - derivative instruments		605	410	(488)
Other comprehensive loss		18,671	(34,334)	(13,028)
Total comprehensive income		308,716	331,811	232,896
Less: comprehensive income attributable to noncontrolling interest		(8,142)	(8,519)	(6,135)
Comprehensive income attributable to common shareholders		$ 300,574	$ 323,292	$ 226,761
Weighted average number of common shares outstanding
Basic (shares)		146,742	146,204	148,243
Diluted (shares)		147,541	146,889	148,843
Amounts attributable to common shareholders
Income from continuing operations		$ 263,805	$ 345,108	$ 229,164
Discontinued operations		18,535	11,709	10,319
Income available to common shareholders		$ 282,340	$ 356,817	$ 239,483
Common shares [Member]
Basic:
Income from continuing operations (USD per share/unit)		$ 1.79	$ 2.36	$ 1.55
Income from discontinued operations (USD per share/unit)		0.13	0.08	0.07
Income per common share - basic (USD per share/unit)		1.92	2.44	1.62
Diluted:
Income from continuing operations (USD per share/unit)		1.78	2.35	1.54
Income from discontinued operations (USD per share/unit)		0.13	0.08	0.07
Income per common share - diluted (USD per share/unit)		$ 1.91	$ 2.43	$ 1.61
Liberty Property Limited Partnership [Member]
OPERATING REVENUE
Rental		$ 486,195	$ 519,368	$ 561,434
Operating expense reimbursement		150,910	178,389	212,526
Development service fee income		82,673	12,941	0
Total operating revenue		719,778	710,698	773,960
OPERATING EXPENSE
Rental property		66,018	94,177	123,997
Real estate taxes		90,187	95,202	101,647
General and administrative		56,975	67,088	68,264
Expensed pursuit costs		5,066	1,016	605
Depreciation and amortization		175,137	196,705	217,864
Development service fee expense		85,805	12,165	0
Impairment - real estate assets		3,946	3,879	17,215
Total operating expense		483,134	470,232	529,592
Operating income		236,644	240,466	244,368
OTHER INCOME (EXPENSE)
Interest and other income		7,778	13,817	23,758
Loss on debt extinguishment		(49)	(27,099)	0
Interest expense		(88,857)	(112,299)	(133,557)
Total other income (expense)		(81,128)	(125,581)	(109,799)
Income before gain on property dispositions, income taxes and equity in earnings of unconsolidated joint ventures		155,516	114,885	134,569
Gain on property dispositions		100,387	219,270	100,314
Income taxes		(1,992)	(1,971)	(2,673)
Equity in earnings of unconsolidated joint ventures		17,155	21,970	3,149
Income from continuing operations		271,066	354,154	235,359
Discontinued operations (including net gain on property dispositions of $14,578 for the year ended December 31, 2017)		18,979	11,991	10,565
Net income		290,045	366,145	245,924
Noncontrolling interest – consolidated joint ventures		(481)	(258)	(249)
Preferred unit distributions		(472)	(472)	(472)
Income available to common shareholders		289,092	365,415	245,203
Comprehensive income attributable to common shareholders
Net income		290,045	366,145	245,924
Other comprehensive income (loss) - foreign currency translation		18,066	(34,744)	(12,540)
Other comprehensive income (loss) - derivative instruments		605	410	(488)
Other comprehensive loss		18,671	(34,334)	(13,028)
Total comprehensive income		$ 308,716	$ 331,811	$ 232,896
Weighted average number of common shares outstanding
Basic (shares)		150,270	149,740	151,783
Diluted (shares)		151,069	150,425	152,383
Net Income Allocated to General Partners		$ 282,340	$ 356,817	$ 239,483
Net Income Allocated to Limited Partners		7,224	9,070	6,192
Amounts attributable to common shareholders
Income from continuing operations		270,585	353,896	235,110
Income available to common shareholders		$ 289,092	$ 365,415	$ 245,203
Liberty Property Limited Partnership [Member] | Common units [Member]
Basic:
Income from continuing operations (USD per share/unit)		$ 1.79	$ 2.36	$ 1.55
Income from discontinued operations (USD per share/unit)		0.13	0.08	0.07
Income per common share - basic (USD per share/unit)		1.92	2.44	1.62
Diluted:
Income from continuing operations (USD per share/unit)		1.78	2.35	1.54
Income from discontinued operations (USD per share/unit)		0.13	0.08	0.07
Income per common share - diluted (USD per share/unit)		$ 1.91	$ 2.43	$ 1.61
[1]	(1) Prior to the fourth quarter of 2016, development service fee income had been classified as other income and development service fee expense had been classified as general and administrative expense. See Note 2.

Consolidated Statements of Com5

Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Discontinued operations, net gain on property dispositions	$ 14,578	$ 0	$ 0
Liberty Property Limited Partnership [Member]
Discontinued operations, net gain on property dispositions	$ 14,578	$ 0	$ 0

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($) $ in Thousands	Total	Liberty Property Limited Partnership [Member]	Liberty Property Limited Partnership [Member]Noncontrolling Interest-Consolidated Joint Ventures [Member]	Liberty Property Limited Partnership [Member]General Partner [Member]	Liberty Property Limited Partnership [Member]Limited Partner [Member]	Common shares [Member]	Common units [Member]Liberty Property Limited Partnership [Member]General Partner [Member]	Common units [Member]Liberty Property Limited Partnership [Member]Limited Partner [Member]	Common Shares Of Beneficial Interest [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Distributions in Excess of Net Income [Member]	Total Liberty Property Trust Shareholders' Equity [Member]	Noncontrolling Interest- Operating Partnership - Common	Noncontrolling Interest-Consolidated Joint Ventures [Member]
Beginning Balance at Dec. 31, 2014	$ 3,106,312	$ 3,106,312	$ 3,919	$ 3,046,961	$ 55,432				$ 149	$ 3,688,644	$ (9,784)	$ (632,048)	$ 3,046,961	$ 55,432	$ 3,919
Common shares outstanding - Beginning Balance (shares) at Dec. 31, 2014						148,557,270
General Partner's units outstanding - Beginning Balance (shares) at Dec. 31, 2014							148,557,270
Limited Partners' units outstanding - Beginning Balance (shares) at Dec. 31, 2014								3,553,566
Increase (Decrease) in Stockholders' Equity
Net proceeds from the issuance of common shares	38,797									38,797			38,797
Net proceeds from the issuance of common shares (shares)						1,328,017
Net income	245,452	245,452	249	239,483	5,720							239,483	239,483	5,720	249
Distributions	(289,240)											(282,123)	(282,123)	(6,868)	(249)
Share-based compensation	13,763									13,763			13,763
Contributions from partners		52,560		52,560
Contributions from partners (shares)							1,328,017
Distributions to partners		(289,240)	(249)	(282,123)	(6,868)
Other comprehensive income (loss) - foreign currency translation	(12,540)	(12,540)		(12,245)	(295)						(12,245)		(12,245)	(295)
Other comprehensive (loss) income - derivative instruments	(488)	(488)		(477)	(11)						(477)		(477)	(11)
Redemption of noncontrolling interests – common units										224			224	(224)
Redemption of noncontrolling interests – common units (shares)						14,491	14,491
Redemption of limited partners common units for common shares				224	(224)
Redemption of limited partners common units for common shares (shares)								(14,491)
Share repurchase	(71,802)	(71,802)		(71,802)					(1)	(71,801)			(71,802)
Share repurchase (shares)						(2,321,794)	(2,321,794)
Common shares outstanding - Ending Balance (shares) at Dec. 31, 2015						147,577,984
Limited Partners' units outstanding - Ending Balance (shares) at Dec. 31, 2015								3,539,075
General Partner's units outstanding - Ending Balance (shares) at Dec. 31, 2015							147,577,984
Ending Balance at Dec. 31, 2015	3,030,254	3,030,254	3,919	2,972,581	53,754				148	3,669,627	(22,506)	(674,688)	2,972,581	53,754	3,919
Noncontrolling interest - operating partnership (mezzanine) - Beginning of Period at Dec. 31, 2014	7,537	7,537
Increase (Decrease) in Limited Partners' Equity
Temporary Equity, Net Income	472	472
Temporary Equity, Distributions	(472)	(472)
Noncontrolling interest - operating partnership (mezzanine) - End of Period at Dec. 31, 2015	7,537	7,537
Increase (Decrease) in Stockholders' Equity
Net proceeds from the issuance of common shares	13,029									13,029			13,029
Net proceeds from the issuance of common shares (shares)						802,834
Net income	365,673	365,673	258	356,817	8,598							356,817	356,817	8,598	258
Distributions	(285,802)											(278,764)	(278,764)	(6,780)	(258)
Share-based compensation	15,699									15,699			15,699
Contributions from partners		28,728		28,728
Contributions from partners (shares)							802,834
Distributions to partners		(285,802)	(258)	(278,764)	(6,780)
Other comprehensive income (loss) - foreign currency translation	(34,744)	(34,744)		(33,925)	(819)						(33,925)		(33,925)	(819)
Other comprehensive (loss) income - derivative instruments	410	410		400	10						400		400	10
Acquisition of noncontrolling interests	(700)	(700)	982	(1,682)						(1,682)			(1,682)		982
Redemption of noncontrolling interests – common units										132			132	(132)
Redemption of noncontrolling interests – common units (shares)						9,044	9,044
Redemption of limited partners common units for common shares				132	(132)
Redemption of limited partners common units for common shares (shares)								(9,044)
Share repurchase	$ (40,896)	$ (40,896)		(40,896)					(1)	(40,895)			(40,896)
Share repurchase (shares)						(1,396,844)	(1,396,844)
Common shares outstanding - Ending Balance (shares) at Dec. 31, 2016	146,993,018	146,993,018				146,993,018
Limited Partners' units outstanding - Ending Balance (shares) at Dec. 31, 2016		3,530,031						3,530,031
General Partner's units outstanding - Ending Balance (shares) at Dec. 31, 2016							146,993,018
Ending Balance at Dec. 31, 2016	$ 3,062,923	$ 3,062,923	4,901	3,003,391	54,631				147	3,655,910	(56,031)	(596,635)	3,003,391	54,631	4,901
Increase (Decrease) in Limited Partners' Equity
Temporary Equity, Net Income	472	472
Temporary Equity, Distributions	(472)	(472)
Noncontrolling interest - operating partnership (mezzanine) - End of Period at Dec. 31, 2016	7,537	7,537
Increase (Decrease) in Stockholders' Equity
Net proceeds from the issuance of common shares	8,808									8,808			8,808
Net proceeds from the issuance of common shares (shares)						447,847
Net income	289,573	289,573	481	282,340	6,752							282,340	282,340	6,752	481
Distributions	(241,717)											(235,675)	(235,675)	(5,509)	(533)
Share-based compensation	10,108									10,108			10,108
Contributions from partners		18,916		18,916
Contributions from partners (shares)							447,847
Distributions to partners		(241,717)	(533)	(235,675)	(5,509)
Other comprehensive income (loss) - foreign currency translation	18,066	18,066		17,643	423						17,643		17,643	423
Other comprehensive (loss) income - derivative instruments	$ 605	$ 605		591	14						591		591	14
Redemption of noncontrolling interests – common units										152			152	(152)
Redemption of noncontrolling interests – common units (shares)						9,826	9,826
Redemption of limited partners common units for common shares				152	(152)
Redemption of limited partners common units for common shares (shares)								(9,826)
Common shares outstanding - Ending Balance (shares) at Dec. 31, 2017	147,450,691	147,450,691				147,450,691
Limited Partners' units outstanding - Ending Balance (shares) at Dec. 31, 2017		3,520,205						3,520,205
General Partner's units outstanding - Ending Balance (shares) at Dec. 31, 2017							147,450,691
Ending Balance at Dec. 31, 2017	$ 3,148,366	$ 3,148,366	$ 4,849	$ 3,087,358	$ 56,159				$ 147	$ 3,674,978	$ (37,797)	$ (549,970)	$ 3,087,358	$ 56,159	$ 4,849
Increase (Decrease) in Limited Partners' Equity
Temporary Equity, Net Income	472	472
Temporary Equity, Distributions	(472)	(472)
Noncontrolling interest - operating partnership (mezzanine) - End of Period at Dec. 31, 2017	$ 7,537	$ 7,537

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
OPERATING ACTIVITIES
Net income	$ 290,045	$ 366,145	$ 245,924
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	183,887	207,673	229,779
Amortization of deferred financing costs	3,750	3,974	4,395
Expensed pursuit costs	5,066	1,016	605
Impairment - real estate assets	10,632	3,879	18,244
Loss on debt extinguishment	49	27,099	0
Equity in earnings of unconsolidated joint ventures	(17,155)	(21,970)	(3,149)
Distributions from unconsolidated joint ventures	0	0	2,444
Gain on property dispositions	(114,965)	(219,270)	(100,314)
Share-based compensation	14,119	19,850	17,152
Other	824	(6,128)	(9,937)
Changes in operating assets and liabilities:
Accounts receivable	3,512	421	1,009
Deferred rent receivable	(19,605)	(16,927)	(23,167)
Prepaid expenses and other assets	(33,663)	(32,442)	(15,145)
Accounts payable	10,151	8,943	1,822
Accrued interest	(82)	(4,276)	1,641
Other liabilities	66	3,075	7,818
Net cash provided by operating activities	336,631	341,062	379,121
INVESTING ACTIVITIES
Investment in properties – acquisitions	(255,639)	(9,216)	(111,811)
Investment in properties – other	(56,104)	(55,406)	(77,626)
Investments in and advances to unconsolidated joint ventures	(46,567)	(70,581)	(43,676)
Distributions from unconsolidated joint ventures	21,042	63,048	33,195
Net proceeds from disposition of properties/land	379,139	1,192,918	530,440
Investment in development in progress	(260,447)	(342,489)	(210,677)
Investment in land held for development	(105,564)	(107,400)	(150,523)
Payment of deferred leasing costs	(37,678)	(32,682)	(48,672)
Increase in escrows	(108,420)	(25,254)	(8,216)
Other	4,586	1,989	(2,094)
Net cash (used in) provided by investing activities	(465,652)	614,927	(89,660)
FINANCING ACTIVITIES
Net proceeds from issuance of common shares	8,808	13,029	38,797
Share repurchases, including shares related to tax withholdings	(5,107)	(46,268)	(76,035)
Proceeds from unsecured notes	0	396,648	398,576
Repayments of unsecured notes including prepayment premium	0	(723,368)	(316,000)
Repayments of mortgage loans	(7,795)	(29,538)	(175,364)
Proceeds from credit facility	835,036	591,300	1,122,700
Repayments on credit facility	(476,097)	(850,300)	(1,030,700)
Payment of deferred financing costs	(5,190)	(3,550)	(3,656)
Distribution paid on common shares	(246,589)	(279,248)	(282,582)
Distribution paid on units/noncontrolling interests	(6,835)	(8,212)	(7,596)
Net cash provided by (used in) financing activities	96,231	(939,507)	(331,860)
Net (decrease) increase in cash, cash equivalents and restricted cash	(32,790)	16,482	(42,399)
Increase (decrease) in cash, cash equivalents and restricted cash related to foreign currency translation	2,450	(4,828)	(2,901)
Cash, cash equivalents and restricted cash	25,685	56,025	44,371
Liberty Property Limited Partnership [Member]
OPERATING ACTIVITIES
Net income	290,045	366,145	245,924
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	183,887	207,673	229,779
Amortization of deferred financing costs	3,750	3,974	4,395
Expensed pursuit costs	5,066	1,016	605
Impairment - real estate assets	10,632	3,879	18,244
Loss on debt extinguishment	49	27,099	0
Equity in earnings of unconsolidated joint ventures	(17,155)	(21,970)	(3,149)
Distributions from unconsolidated joint ventures	0	0	2,444
Gain on property dispositions	(114,965)	(219,270)	(100,314)
Share-based compensation	14,119	19,850	17,152
Other	824	(6,128)	(9,937)
Changes in operating assets and liabilities:
Accounts receivable	3,512	421	1,009
Deferred rent receivable	(19,605)	(16,927)	(23,167)
Prepaid expenses and other assets	(33,663)	(32,442)	(15,145)
Accounts payable	10,151	8,943	1,822
Accrued interest	(82)	(4,276)	1,641
Other liabilities	66	3,075	7,818
Net cash provided by operating activities	336,631	341,062	379,121
INVESTING ACTIVITIES
Investment in properties – acquisitions	(255,639)	(9,216)	(111,811)
Investment in properties – other	(56,104)	(55,406)	(77,626)
Investments in and advances to unconsolidated joint ventures	(46,567)	(70,581)	(43,676)
Distributions from unconsolidated joint ventures	21,042	63,048	33,195
Net proceeds from disposition of properties/land	379,139	1,192,918	530,440
Investment in development in progress	(260,447)	(342,489)	(210,677)
Investment in land held for development	(105,564)	(107,400)	(150,523)
Payment of deferred leasing costs	(37,678)	(32,682)	(48,672)
Increase in escrows	(108,420)	(25,254)	(8,216)
Other	4,586	1,989	(2,094)
Net cash (used in) provided by investing activities	(465,652)	614,927	(89,660)
FINANCING ACTIVITIES
Proceeds from unsecured notes	0	396,648	398,576
Repayments of unsecured notes including prepayment premium	0	(723,368)	(316,000)
Repayments of mortgage loans	(7,795)	(29,538)	(175,364)
Proceeds from credit facility	835,036	591,300	1,122,700
Repayments on credit facility	(476,097)	(850,300)	(1,030,700)
Payment of deferred financing costs	(5,190)	(3,550)	(3,656)
Capital contributions	8,808	13,029	38,797
Distributions to partners/noncontrolling interests	(258,531)	(333,728)	(366,213)
Net cash provided by (used in) financing activities	96,231	(939,507)	(331,860)
Net (decrease) increase in cash, cash equivalents and restricted cash	(32,790)	16,482	(42,399)
Increase (decrease) in cash, cash equivalents and restricted cash related to foreign currency translation	2,450	(4,828)	(2,901)
Cash, cash equivalents and restricted cash	$ 25,685	$ 56,025	$ 44,371

Organization

Organization	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	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 December 31, 2017 . The Company owns and operates industrial properties nationally and owns and operates office properties in a focused group of office markets. Additionally, the Company owns certain assets in the United Kingdom. Unless otherwise indicated, the notes to the Consolidated Financial Statements apply to both the Trust and the Operating Partnership. The terms the "Company,” “we,” “our” and “us” means 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 $17.3 million and $18.7 million as of December 31, 2017 and 2016, respectively. All square footage amounts are unaudited.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles ("US GAAP") requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Principles of Consolidation The consolidated financial statements of the Company include the Trust, the Operating Partnership, wholly owned subsidiaries and those subsidiaries in which the Company owns a majority voting interest with the ability to control operations of the subsidiaries and where no approval, veto or other important rights have been granted to the noncontrolling shareholders. The Company consolidates joint ventures that are considered to be variable interest entities (“VIEs”) where we are the primary beneficiary. The Company (i) evaluates the sufficiency of the total equity investment at risk, (ii) reviews the voting rights and decision-making authority of the equity investment holders as a group and whether there are any guaranteed returns, protection against losses, or capping of residual returns within the group and (iii) establishes whether activities within the venture are on behalf of an investor with disproportionately few voting rights in making this VIE determination. To the extent that the Company (i) is the sole entity that has the power to direct the activities of the VIE and (ii) has the obligation or rights to absorb the VIE's losses or receive its benefits, then the Company would be the primary beneficiary and would consolidate the VIE. All significant intercompany transactions and accounts have been eliminated. Reclassifications Certain amounts from prior years have been reclassified to conform to current-year presentation including reclassifying the accompanying consolidated balance sheets for assets held for sale and the consolidated statements of comprehensive income for discontinued operations. In 2017, the Company began to separately classify expensed pursuit costs in the Consolidated Statements of Comprehensive Income. These costs, which were reclassed retrospectively for all periods, were formerly classified as general and administrative expense. Concentration of Credit Risk As of December 31, 2017, wholly owned properties were leased to 1,091 customers. The geographic locations that comprise greater than 10% of our rental and other revenues were Lehigh Valley/Central PA and Philadelphia. Our customers engage in a wide variety of businesses. No single customer generated more than 4.6% of our consolidated operating rental revenues during 2017. Real Estate and Depreciation The properties are recorded at cost and are depreciated using the straight line method over their estimated useful lives. The estimated useful lives are as follows: Building and improvements 40 years (blended) Capital improvements 15 - 20 years Equipment 5 - 10 years Tenant improvements Term of the related lease The Company capitalizes costs associated with development and redevelopment activities, capital improvements, tenant improvements and leasing activities, including compensation costs. Expenditures directly related to the improvement of real estate, including interest and other costs capitalized on development and redevelopment projects and land being readied for development, are included in net real estate and are stated at cost. The Company considers a development property substantially complete upon the completion of tenant build-out, but no later than one year after the completion of major construction activity. These capitalized costs include pre-construction costs essential to the development of the property, construction costs, interest costs, real estate taxes, development related compensation and other costs incurred during the period of development. The determination to capitalize rather than expense costs requires the Company to evaluate the status of the development activity. The total of capitalized compensation costs directly related to development, redevelopment, capital improvements, and tenant improvements for the years ended December 31, 2017 , 2016 and 2015 was $5.5 million , $7.2 million and $5.5 million , respectively. Construction related payables at December 31, 2017 and 2016 were $49.3 million and $37.1 million , respectively. The Company allocates the purchase price of real estate acquired to land, building and improvements and intangibles based on the relative fair value of each component. Lease values for acquired properties are determined based on the present value (using a discount rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management's estimate of fair market lease rates for each corresponding in-place lease ("Market Value Intangible"). Origination values are also assigned to in-place leases, and, where appropriate, value is assigned to customer relationships ("Origination Value Intangible"). Acquisition-related costs for vacant properties are capitalized and included in net real estate at cost. Beginning on October 1, 2016, acquisition-related costs for properties with in-place leases deemed to be asset acquisitions are also capitalized and included in net real estate at cost. Expenditures for maintenance and repairs are charged to operations as incurred. The Company depreciates the amounts allocated to building and improvements over 40 years and amortizes the amounts allocated to intangibles relating to in-place leases, which are included in deferred financing and leasing costs and other liabilities in the accompanying consolidated balance sheets, over the remaining term of the related leases. Market Value Intangible amortization is recorded as rental revenue. Origination Value Intangible amortization is recorded as depreciation and amortization. This calculation includes both the remaining noncancelable period and any bargain renewal option periods. Once a property is designated as held for sale, no further depreciation expense is recorded. The Company evaluates its real estate investments upon occurrence of a significant adverse change in its operations to assess whether any impairment indicators are present that affect the recovery of the recorded value. If indicators of impairment are identified, the Company estimates the future undiscounted cash flows from the use and eventual disposition of the property and compares this amount to the carrying value of the property. If any real estate investment is considered impaired, a loss is recognized to reduce the carrying value of the property to its estimated fair value. If held for sale, a property is not considered impaired unless its estimated fair value (less costs to sell) is less than the property's book value at the balance sheet date. Investments in Unconsolidated Joint Ventures The Company accounts for its investments in unconsolidated joint ventures using the equity method of accounting as the Company exercises significant influence, but does not control these entities. Under the equity method of accounting, the net equity investment of the Company is reflected in the accompanying consolidated balance sheets and the Company's share of net income from the joint ventures is included in the accompanying consolidated statements of comprehensive income. On a periodic basis, management assesses whether there are any indicators that the value of the Company's investments in unconsolidated joint ventures may be other-than-temporarily-impaired. An investment is impaired only if management's estimate of the value of the investment is less than the carrying value of the investment, and such decline in value is deemed to be other-than-temporary. To the extent impairment has occurred, the loss is measured as the excess of the carrying amount of the investment over the estimated fair value of the investment. The estimated fair value of the investments is determined using a discounted cash flow model which is a Level 3 valuation under ASC 820, " Fair Value Measurement ." The Company considers a number of assumptions that are subject to economic and market uncertainties including, among others, demand for space, competition for tenants, changes in market rental rates, operating costs, capitalization rates, holding periods and discount rates. No other-than-temporary impairment losses on the Company's investments in unconsolidated joint ventures were recognized during the years ended December 31, 2015, 2016 or 2017. Cash and Cash Equivalents Highly liquid investments with a maturity of three months or less when purchased are classified as cash equivalents. Restricted Cash 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 residential land in Kent County, United Kingdom. Accounts Receivable/Deferred Rent Receivable The Company's accounts receivable are comprised of rents and charges for property operating costs due from tenants. The Company's deferred rent receivable represents the cumulative difference between rent revenue recognized on a straight line basis and contractual payments due under the terms of tenant leases. The Company periodically performs a detailed review of amounts due from tenants to determine if accounts receivable and deferred rent receivable balances are collectible. Based on this review, accounts receivable and deferred rent receivable are reduced by an allowance for doubtful accounts. The Company considers tenant credit quality and payment history and general economic conditions in determining the allowance for doubtful accounts. If the accounts receivable balance or the deferred rent receivable balance is subsequently deemed uncollectible, the receivable and allowance for doubtful account balance are written off. The allowance for doubtful accounts at December 31, 2017 and 2016 was $6.6 million and $7.3 million , respectively. The Company recognized bad debt expense of $0.6 million , $0.6 million and $2.0 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Revenue Recognition The Company earns rental income under operating leases with tenants. Rental income is recognized on a straight line basis over the applicable non-cancelable lease term. Operating expense reimbursements consisting of amounts due from tenants for real estate taxes, utilities and other recoverable costs are recognized as revenue in the period in which the corresponding expenses are incurred. The Company considers any renewal options in determining the lease term. To the extent a lease includes a tenant option to renew or extend the duration of the lease at a fixed or determinable rental rate, the Company evaluates whether or not that option represents a bargain renewal option by analyzing if there is reasonable assurance at lease inception that the tenant will exercise the option because the rental rate is sufficiently lower than the expected rental rate for equivalent property under similar terms and conditions at the exercise date. Termination fees (included in rental revenue) are fees that the Company has agreed to accept in consideration for permitting certain tenants to terminate their lease prior to the contractual expiration date. The Company recognizes termination fees during the period that landlord services are rendered in accordance with Securities and Exchange Commission Staff Accounting Bulletin 104, " Revenue Recognition ," after the following conditions are met: a. the termination agreement is executed, b. the termination fee is determinable, and c. collectability of the termination fee is assured. In the fourth quarter of 2016, the Company entered into an agreement relating to the fee development of an office building at its Camden Waterfront project in Camden, NJ. Project revenues and related costs and expenses are presented on a gross basis as "Development service fee income" and "Development service fee expense" in the Consolidated Statements of Comprehensive Income. Additionally, at the same time, the Company began classifying development fees and expenses relating to its fee development arrangements for certain unconsolidated joint venture projects in a manner consistent with the Camden project described above. Previously, development service fee income relating to its unconsolidated joint ventures had been classified as other income and development service fee expense had been classified as general and administrative expense in amounts as follows: Nine months ended Year ended September 30, 2016 December 31, 2015 (unaudited) Other income $ 3,789 $ 6,159 General and administrative expense $ 3,210 $ 3,730 Revenue and expense associated with service fee development is accounted for under the percentage of completion method. Revenues are recognized on the percentage of completion method based on applicable costs incurred with respect to each development agreement. The Company uses the relative sales value method to allocate costs and recognize profits from service fee development. Under the relative sales value method, estimates of aggregate project revenues and aggregate project costs are used to determine the allocation of project cost of sales and the resulting profit in each accounting period. In subsequent periods, cost of sale allocations and the resulting profits are adjusted to reflect changes in the actual and estimated costs and revenues of each project. Provisions for estimated losses on uncompleted contracts are recognized immediately in the period in which such losses are determined. Deferred Financing and Leasing Costs Costs incurred in connection with the financing of the credit facilities or leasing are capitalized and amortized on a straight line basis over the term of the related loan or lease. Costs incurred in connection with the financing of mortgage loans or unsecured notes are reported as a deduction from the face amount of that liability and amortized on a straight line basis over the term of the related loan. Deferred financing cost amortization is reported as interest expense. Certain employees of the Company are compensated for leasing services related to the Company's properties. The compensation directly related to these leasing services is capitalized and amortized as a deferred leasing cost over the term of the related lease. The total of this capitalized compensation was $3.6 million , $3.8 million and $4.6 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Fair Value of Financial Instruments ASC 820, Fair Value Measurements and Disclosures , gives 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, 2017 and December 31, 2016 . 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 also 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 20 - Derivative Instruments. The Company used a discounted cash flow model to determine the estimated fair value of its debt as of December 31, 2017 and December 31, 2016 . 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 at December 31, 2016 and December 31, 2017 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2016 $ 276,650 $ 286,684 $ 2,280,286 $ 2,340,762 As of December 31, 2017 $ 267,093 $ 267,298 $ 2,283,513 $ 2,359,998 Income Taxes The Company has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the "Code"). As a result, the Company generally is not subject to federal income taxation at the corporate level to the extent it distributes annually at least 100% of its REIT taxable income, as defined in the Code, to its shareholders and satisfies certain other organizational and operational requirements. The Company has met these requirements and, accordingly, no provision has been made for federal income taxes in the accompanying consolidated financial statements. If the Company fails to qualify as a REIT in any taxable year, the Company will be subject to federal income tax on its taxable income at regular corporate rates (including any alternative minimum tax) and may not be able to qualify as a REIT for the four subsequent taxable years. Even as a REIT, the Company may still be subject to certain state and local income and property taxes, and to federal income and excise taxes on undistributed taxable income. The Company has considered the provisions of the Tax Cuts and Jobs Act (the "TCJA"), which was signed into law on December 22, 2017 and which generally takes effect for taxable years beginning on or after January 1, 2018, and does not expect the TCJA to have a material impact on its overall business operations or ability to continue to qualify as a REIT. Several of the Company's subsidiaries are taxable REIT subsidiaries (each a "TRS") and are subject to federal and state income taxes separate from the Company. In general, a TRS may perform additional services for tenants and generally may engage in real estate or non-real estate businesses that are not permitted REIT activities. The Company itself is also subject to tax in certain states and the United Kingdom. Accordingly, the Company recognizes federal, state and foreign income taxes in accordance with US GAAP, as applicable. In addition, the TCJA implemented a one-time deemed repatriation tax on offshore corporate profits, including any such profits which the Company may have accumulated over the years in its offshore TRSs, at the reduced rates of 15.5% on cash assets and 8% on noncash assets. The Company has reviewed its accumulated offshore earnings through December 31, 2017 and does not expect this provision of the TCJA will have a material impact on the Company’s overall financial condition or results of operation. There are no uncertain tax positions or possibly significant unrecognized tax benefits that are reasonably expected to occur within the next 12 months. The Company's policy is to recognize interest accrued related to unrecognized benefits in interest expense and penalties in other expense. There were no interest or penalties deducted in any of the years ended December 31, 2017 , 2016 and 2015 and no interest and penalties accrued at December 31, 2017 or December 31, 2016 which related to any uncertain tax positions or significant unrecognized tax benefits. Certain of the Company's TRSs had net operating loss ("NOL") carryforwards available of approximately $40.6 million as of December 31, 2017 . The TCJA reduced the corporate federal tax rate in the U.S. to 21.0% effective for tax years beginning after December 31, 2017. As such, deferred tax assets and liabilities, where applicable, were remeasured using the lower corporate federal tax rate at December 31, 2017. These NOL carryforwards begin to expire in 2018 . After taking into consideration future taxable income and consistent with prior periods, the Company has determined that a valuation allowance for the full carrying value of NOL carryforwards is appropriate. The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction, certain state and local jurisdictions, the United Kingdom and (in prior years) Luxembourg. With few exceptions, the Company and its subsidiaries are no longer subject to examination by taxing authorities in these jurisdictions for years prior to 2011. The Federal tax cost basis of the wholly owned real estate was $6.8 billion and $6.5 billion at December 31, 2017 and 2016 , respectively. Share-Based Compensation Share-based compensation cost is measured at the grant date, based on the fair value of the award, and is recognized as expense over the employees' requisite service period. The Company recognizes forfeitures on share based compensation as they occur. Expensed Pursuit Costs The Company capitalizes pre-development costs incurred in pursuit of new development opportunities for which the Company currently believes future development is probable. Future development is dependent upon various factors, including zoning and regulatory approval, rental market conditions and construction costs. Initial pre-development costs incurred for pursuits for which future development is not yet considered probable are expensed as incurred. In addition, if the status of a future development by the Company is no longer probable, any capitalized pre-development costs are written off with a charge to expense. Derivative Financial Instruments We borrow funds at a combination of fixed and variable rates. Borrowings under our revolving credit facility and certain bank mortgage loans bear interest at variable rates. Our long-term debt typically bears interest at fixed rates. Our interest rate risk management objectives are to limit generally the impact of interest rate changes on earnings and cash flows and to lower our overall borrowing costs. To achieve these objectives, from time to time, we enter into interest rate hedge contracts such as collars, swaps, caps and treasury lock agreements in order to mitigate our interest rate risk with respect to various debt instruments. We generally do not hold or issue these derivative contracts for trading or speculative purposes. The interest rate on all of our variable rate debt is generally adjusted at one or three month intervals, subject to settlements under interest rate hedge contracts. Interest rate swaps involve the receipt of variable-rate amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive loss (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. Foreign Currency The functional currency of the Company's United Kingdom operations is pounds sterling. The Company translates the financial statements for the United Kingdom operations into US dollars. For the Trust, gains and losses resulting from this translation are included in accumulated other comprehensive loss as a separate component of shareholders' equity and a proportionate amount of gain or loss is allocated to noncontrolling interest - operating partnership - common units. For the Operating Partnership, gains and losses resulting from this translation are included in general partner's equity and limited partners' equity - common units. Upon sale or upon complete or substantially complete liquidation of the Company's foreign investment, the gain or loss on the sale will include the cumulative translation adjustments that have been previously recorded in accumulated other comprehensive loss and noncontrolling interest - operating partnership - common units (for the Trust) and in general partner's equity and limited partners' equity - common units (for the Operating Partnership). Comprehensive Income Comprehensive income, as reflected on the consolidated statements of comprehensive income, is defined as all changes in equity during each period except for those resulting from investments by or distributions to shareholders. Accumulated other comprehensive loss, as reflected on the Company's consolidated balance sheets and consolidated statements of equity, reflects the effective portion of the cumulative changes in the fair value of derivatives in qualifying cash flow hedge relationships as well as gains and losses resulting from foreign currency translation. Sales of Real Estate The Company accounts for the sale of real estate assets and any related gain recognition in accordance with the accounting guidance applicable to sales of real estate, which establishes standards for recognition of profit on all real estate sales transactions, other than retail land sales. The Company recognizes the sale, and associated gain or loss from the disposition, provided that the earnings process is complete and the Company is not obligated to perform significant activities after the sale. Earnings Per Share of the REIT Basic earnings per share is calculated by dividing the income available to common shareholders for the period by the weighted average number of common shares outstanding during the period using the two class method. Diluted earnings per share is calculated by dividing the net income available to common shareholders for the period by the weighted average number of common and dilutive securities outstanding during the period. Earnings Per Unit of the Operating Partnership Basic earnings per unit is calculated by dividing the income available to common unitholders for the period by the weighted average number of common units outstanding during the period using the two class method. Diluted earnings per unit is calculated by dividing the income available to common unitholders for the period by the weighted average number of common and dilutive securities outstanding during the period. Recently Issued Accounting Standards 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 the following standards related to ASU 2014-09: ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations; ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ; ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ; and ASU 2017-13, Revenue from Contracts with Customers (Topic 606): Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments (collectively, the “New Revenue Standards”). The New Revenue Standards clarify the required factors that an entity must consider when recognizing revenue and require additional disclosures concerning contracts with customers, judgments concerning revenue recognition, and assets recognized for the costs to obtain or fulfill a contract. The Company concluded that there are no revenue streams from its lease agreements that are covered by the New Revenue Standards with the exception of non-lease components as further discussed below. Once the new guidance setting forth principles for the recognition, measurement, presentation and disclosure of leases goes into effect on January 1, 2019, the Company believes that the New Revenue Standards will apply to components of revenue due under leases that are deemed to be non-lease components (such as common area maintenance and provision of utilities), which could affect the recognition pattern for such revenue. The Company has completed its evaluation of the New Revenue Standards' impact on its remaining revenue streams. The Company adopted this standard effective January 1, 2018 using the modified retrospective approach, which requires applying the new standard to all existing contracts not yet completed as of the effective date and recording a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The New Revenue Standards will not have a material impact on the measurement and recognition of gains and losses on the sale of properties. The New Revenue Standards will not have a material impact on the amount and timing of recognizing its development service fee income, which is currently accounted for under the percentage of completion method based on applicable costs incurred and estimated to be incurred. The Company has completed its evaluation of the standard's impact on its revenue streams. The Company does not believe the adoption of the New Revenue Standards will have a material impact on the consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"). ASU 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU 2016-02 is effective for the Company beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. The standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. For leases in which the Company is the lessor, the standard requires that the lease and non-lease components of the lease agreement should be separated. Revenue related to the lease component of the contract will be recognized on a straight-line basis, while revenue related to the non-lease component will be recognized under the provisions of the New Revenue Standards. For lease agreements longer than one year in which the Company is the lessee, the Company will measure the present value of the future lease payments and recognize a right-of-use asset and corresponding lease liability on its balance sheet. In addition, the new standard states that only direct leasing costs may be capitalized. The Company is evaluating the impact ASU 2016-02 will have on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships ("ASU 2016-05"). ASU 2016-05 states that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under FASB Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted ASU 2016-05 beginning January 1, 2017 on a prospective basis.

Income per Common Share of the

Income per Common Share of the Trust	12 Months Ended
	Dec. 31, 2017
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): 2017 2016 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 $ 263,805 146,742 $ 1.79 $ 345,108 146,204 $ 2.36 Dilutive shares for long-term compensation plans — 799 — 685 Income from continuing operations net of noncontrolling interest - diluted $ 263,805 147,541 $ 1.78 $ 345,108 146,889 $ 2.35 Discontinued operations net of noncontrolling interest - basic $ 18,535 146,742 $ 0.13 $ 11,709 146,204 $ 0.08 Dilutive shares for long-term compensation plans — 799 — 685 Discontinued operations net of noncontrolling interest - diluted $ 18,535 147,541 $ 0.13 $ 11,709 146,889 $ 0.08 Net income available to common shareholders - basic $ 282,340 146,742 $ 1.92 $ 356,817 146,204 $ 2.44 Dilutive shares for long-term compensation plans — 799 — 685 Net income available to common shareholders - diluted $ 282,340 147,541 $ 1.91 $ 356,817 146,889 $ 2.43 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 229,164 148,243 $ 1.55 Dilutive shares for long-term compensation plans — 600 Income from continuing operations net of noncontrolling interest - diluted $ 229,164 148,843 $ 1.54 Discontinued operations net of noncontrolling interest - basic $ 10,319 148,243 $ 0.07 Dilutive shares for long-term compensation plans — 600 Discontinued operations net of noncontrolling interest - diluted $ 10,319 148,843 $ 0.07 Net income available to common shareholders - basic $ 239,483 148,243 $ 1.62 Dilutive shares for long-term compensation plans — 600 Net income available to common shareholders - diluted $ 239,483 148,843 $ 1.61 Dilutive shares for long-term compensation plans represent the unvested common shares outstanding during the year as well as the dilutive effect of outstanding options. There were no anti-dilutive options in 2017. The amounts of anti-dilutive options that were excluded from the computation of diluted income per common share as the exercise price was higher than the average share price of the Company in 2016 and 2015 were 0.8 million and 1.5 million , respectively. During the years ended December 31, 2017 , 2016 and 2015 , 193,000 , 369,000 and 65,000 common shares, respectively, were issued upon the exercise of options. During the years ended December 31, 2017 , 2016 and 2015 , individuals acquired 9,826 , 9,044 and 14,491 common shares, respectively, in exchange for the same number of common units. These individuals acquired these common units in connection with their contributions to the Operating Partnership of certain assets in prior years. The exchange of common shares for the common units is exempt from the registration requirement of the Securities Act of 1933, as amended, pursuant to Section 4(2) thereunder. During the years ended December 31, 2017 , 2016 and 2015 , declared dividends per common share were $1.60 , $ 1.90 and $ 1.90 , respectively.

Income per Common Unit of the O

Income per Common Unit of the Operating Partnership	12 Months Ended
	Dec. 31, 2017
Earnings Per Unit, Basic and Diluted [Line Items]
Income per Common Unit of the Operating Partnership	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): 2017 2016 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 $ 263,805 146,742 $ 1.79 $ 345,108 146,204 $ 2.36 Dilutive shares for long-term compensation plans — 799 — 685 Income from continuing operations net of noncontrolling interest - diluted $ 263,805 147,541 $ 1.78 $ 345,108 146,889 $ 2.35 Discontinued operations net of noncontrolling interest - basic $ 18,535 146,742 $ 0.13 $ 11,709 146,204 $ 0.08 Dilutive shares for long-term compensation plans — 799 — 685 Discontinued operations net of noncontrolling interest - diluted $ 18,535 147,541 $ 0.13 $ 11,709 146,889 $ 0.08 Net income available to common shareholders - basic $ 282,340 146,742 $ 1.92 $ 356,817 146,204 $ 2.44 Dilutive shares for long-term compensation plans — 799 — 685 Net income available to common shareholders - diluted $ 282,340 147,541 $ 1.91 $ 356,817 146,889 $ 2.43 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 229,164 148,243 $ 1.55 Dilutive shares for long-term compensation plans — 600 Income from continuing operations net of noncontrolling interest - diluted $ 229,164 148,843 $ 1.54 Discontinued operations net of noncontrolling interest - basic $ 10,319 148,243 $ 0.07 Dilutive shares for long-term compensation plans — 600 Discontinued operations net of noncontrolling interest - diluted $ 10,319 148,843 $ 0.07 Net income available to common shareholders - basic $ 239,483 148,243 $ 1.62 Dilutive shares for long-term compensation plans — 600 Net income available to common shareholders - diluted $ 239,483 148,843 $ 1.61 Dilutive shares for long-term compensation plans represent the unvested common shares outstanding during the year as well as the dilutive effect of outstanding options. There were no anti-dilutive options in 2017. The amounts of anti-dilutive options that were excluded from the computation of diluted income per common share as the exercise price was higher than the average share price of the Company in 2016 and 2015 were 0.8 million and 1.5 million , respectively. During the years ended December 31, 2017 , 2016 and 2015 , 193,000 , 369,000 and 65,000 common shares, respectively, were issued upon the exercise of options. During the years ended December 31, 2017 , 2016 and 2015 , individuals acquired 9,826 , 9,044 and 14,491 common shares, respectively, in exchange for the same number of common units. These individuals acquired these common units in connection with their contributions to the Operating Partnership of certain assets in prior years. The exchange of common shares for the common units is exempt from the registration requirement of the Securities Act of 1933, as amended, pursuant to Section 4(2) thereunder. During the years ended December 31, 2017 , 2016 and 2015 , declared dividends per common share were $1.60 , $ 1.90 and $ 1.90 , respectively.
Liberty Property Limited Partnership [Member]
Earnings Per Unit, Basic and Diluted [Line Items]
Income per Common Unit of the Operating Partnership	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): 2017 2016 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 $ 270,585 $ 353,896 Less: Preferred unit distributions (472 ) (472 ) Income from continuing operations available to common unitholders - basic $ 270,113 150,270 $ 1.79 $ 353,424 149,740 $ 2.36 Dilutive units for long-term compensation plans — 799 — 685 Income from continuing operations available to common unitholders - diluted $ 270,113 151,069 $ 1.78 $ 353,424 150,425 $ 2.35 Income from discontinued operations - basic $ 18,979 150,270 $ 0.13 $ 11,991 149,740 $ 0.08 Dilutive units for long-term compensation plans 799 685 Income from discontinued operations - diluted $ 18,979 151,069 $ 0.13 $ 11,991 150,425 $ 0.08 Income available to common unitholders - basic $ 289,092 150,270 $ 1.92 $ 365,415 149,740 $ 2.44 Dilutive units for long-term compensation plans 799 685 Income available to common unitholders - diluted $ 289,092 151,069 $ 1.91 $ 365,415 150,425 $ 2.43 2015 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations net of noncontrolling interest - consolidated joint ventures $ 235,110 Less: Preferred unit distributions (472 ) Income from continuing operations available to common unitholders - basic $ 234,638 151,783 $ 1.55 Dilutive units for long-term compensation plans — 600 Income from continuing operations available to common unitholders - diluted $ 234,638 152,383 $ 1.54 Income from discontinued operations - basic $ 10,565 151,783 $ 0.07 Dilutive units for long-term compensation plans — 600 Income from discontinued operations - diluted $ 10,565 152,383 $ 0.07 Income available to common unitholders - basic $ 245,203 151,783 $ 1.62 Dilutive units for long-term compensation plans — 600 Income available to common unitholders - diluted $ 245,203 152,383 $ 1.61 Dilutive units for long-term compensation plans represent the unvested common units outstanding during the year as well as the dilutive effect of outstanding options. There were no anti-dilutive options in 2017. The amounts of anti-dilutive options that were excluded from the computation of diluted income per common unit as the exercise price was higher than the average unit price of the Company in 2016 and 2015 were 0.8 million and 1.5 million , respectively. During the years ended December 31, 2017 , 2016 and 2015 , 193,000 , 369,000 and 65,000 common units, respectively, were issued upon the exercise of options. During the years ended December 31, 2017 , 2016 and 2015 , individuals acquired 9,826 , 9,044 and 14,491 common shares of the Trust in exchange for the same number of common units of the Operating Partnership. These individuals acquired these common units in connection with their contributions to the Operating Partnership of certain assets in prior years. The exchange of common shares for the common units is exempt from the registration requirement of the Securities Act of 1933, as amended, pursuant to Section 4(2) thereunder. During the years ended December 31, 2017 , 2016 and 2015 , declared dividends per common unit were $1.60 , $1.90 and $1.90 , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	ACCUMULATED OTHER COMPREHENSIVE LOSS The following table sets forth the components of Accumulated Other Comprehensive Loss (in thousands): December 31, 2017 2016 Foreign Currency Translation: Beginning balance $ (56,767 ) $ (22,023 ) Translation adjustment 18,066 (34,744 ) Ending balance (38,701 ) (56,767 ) Derivative Instruments: Beginning balance (455 ) (865 ) Unrealized loss 152 (659 ) Reclassification adjustment (1) 453 1,069 Ending balance 150 (455 ) Total accumulated other comprehensive loss (38,551 ) (57,222 ) Less: portion included in noncontrolling interest – operating partnership 754 1,191 Total accumulated other comprehensive loss included in shareholders' equity $ (37,797 ) $ (56,031 ) (1) Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate

Real Estate	12 Months Ended
	Dec. 31, 2017
Real Estate [Abstract]
Real Estate	REAL ESTATE The Company owns and operates industrial and office properties. The carrying value of these operating properties by type as of December 31, 2017 and 2016 is as follows (in thousands): Land Building and Land and Accumulated Improvements Improvements Total Depreciation 2017 Industrial properties $ 1,001,454 $ 3,873,830 $ 4,875,284 $ 814,301 Office properties 152,226 569,753 721,979 126,312 2017 Total $ 1,153,680 $ 4,443,583 $ 5,597,263 $ 940,613 2016 Industrial properties $ 914,428 $ 3,725,331 $ 4,639,759 $ 719,658 Office properties 145,637 572,681 718,318 127,448 2016 Total $ 1,060,065 $ 4,298,012 $ 5,358,077 $ 847,106 Depreciation expense was $148.9 million , $166.8 million and $181.0 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Information on the operating properties the Company sold during the years ended December 31, 2017 , 2016 and 2015 is as follows: 2017 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Chicago/Minneapolis 3 — 136,110 $ 8,917 Florida — 16 — 13,256 Houston 1 42 206,808 36,145 Lehigh/Central PA 2 44 1,683,876 249,045 Southeastern PA 4 3 313,410 56,156 Other — 8 — 3,739 Total 10 113 2,340,204 $ 367,258 2016 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Chicago/Minneapolis 24 5 2,037,275 $ 199,825 Florida 51 12 3,509,641 505,828 Lehigh/Central PA 1 — 120,777 11,200 Philadelphia — 1 — 2,640 Southeastern PA 31 — 2,165,002 266,821 Other 18 18 1,631,295 224,241 Total 125 36 9,463,990 $ 1,210,555 2015 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Carolinas/Richmond 22 3 1,319,299 $ 110,054 Chicago/Minneapolis 2 — 222,642 25,700 Florida 4 — 874,125 55,425 Southeastern PA 46 20 2,724,489 316,583 Other 7 — 569,618 37,371 Total 81 23 5,710,173 $ 545,133 Included in the sales for the year ended December 31, 2015 are 22 properties and three acres of land in the Carolinas/Richmond segment that the Company sold for $110.3 million to a firm in which the brother of David L. Lingerfelt, a member of the Company's Board of Trustees, has an equity interest. During the year ended December 31, 2015, the Company completed a portfolio sale consisting of 41 properties and 20 acres of land in the Southeastern PA segment. As of December 31, 2016, the Company had deferred gain recognition related to this sale in the amount of $14.3 million which is recorded in other liabilities on the accompanying consolidated balance sheets. During the year ended December 31, 2017, the contingency related to the portfolio sale was settled and the Company recognized the deferred gain in the accompanying statements of comprehensive income. Information on the operating properties and land parcels the Company acquired during the years ended December 31, 2017 , 2016 and 2015 is as follows: 2017 Acquisitions Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Purchase Price (in thousands) Carolinas/Richmond — 11 — $ 1,242 Lehigh/Central PA — 95 — 17,798 United Kingdom — 35 — 12,550 Other 8 113 1,861,879 264,808 Total 8 254 1,861,879 $ 296,398 2016 Acquisitions Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Purchase Price (in thousands) Carolinas/Richmond — 13 — $ 2,251 Chicago/Minneapolis 1 6 73,160 11,064 Lehigh/Central PA — 76 — 15,395 Philadelphia — 6 — 13,943 Southeastern PA — 8 — 3,344 Other — 108 — 14,895 Total 1 217 73,160 $ 60,892 2015 Acquisitions Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Purchase Price (in thousands) Carolinas/Richmond — 94 — $ 1,727 Chicago/Minneapolis 1 188 197,956 24,541 Houston 3 139 921,196 86,497 Lehigh/Central PA — 281 — 62,402 Other 1 56 410,059 45,248 Total 5 758 1,529,211 $ 220,415 Subsequent to December 31, 2017, the Company closed on the acquisition of a 400,000 square foot property in its Southern California segment for a Total Investment of $92.7 million .

Investments in Unconsolidated J

Investments in Unconsolidated Joint Ventures	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Joint Ventures	INVESTMENTS IN UNCONSOLIDATED JOINT VENTURES Listed below are the unconsolidated joint ventures in which the Company has a noncontrolling interest. The Company receives fees from these joint ventures for services it provides. These services include property management, leasing, development and administration. These fees are generally included in interest and other income in the accompanying consolidated statements of comprehensive income. For the three months ended December 31, 2016, the Company began including development-related fees in development service income in the consolidated statements of comprehensive income. The Company may also receive a promoted interest if certain return thresholds are met. The accounting policies for the unconsolidated joint ventures in which the Company has a noncontrolling interest are the same as those for the Company. On a periodic basis, management assesses whether there are any indicators that the value of the properties owned by the unconsolidated joint ventures may be impaired. As detailed below, management has determined that certain assets are impaired as the unconsolidated joint ventures dispose of and anticipate the potential disposition of certain properties prior to the end of their remaining useful lives. Liberty Venture I, LP As of December 31, 2017 , the Company had a 25% interest in Liberty Venture I, LP, an entity engaged in the ownership of industrial properties in New Jersey. This joint venture is part of the Company's New Jersey reportable segment. As of December 31, 2017 , the joint venture owned 28 industrial properties totaling 4.5 million square feet. The joint venture also had one property under development, which is expected to comprise, upon completion, 302,000 square feet and is expected to represent a Total Investment of $21.1 million . During the year ended December 31, 2015, the joint venture realized gross proceeds of $8.5 million from the sale of one property totaling 198,000 square feet. The Company had a receivable from Liberty Venture I, LP for $223,000 and $250,000 as of December 31, 2017 and 2016, respectively. This related party receivable is reflected as prepaid expenses and other assets in the Company's consolidated balance sheets. The Company recognized $1.6 million , $2.3 million and $1.6 million in fees for services during the years ended December 31, 2017 , 2016 and 2015 , respectively. Kings Hill Unit Trust As of December 31, 2017 , the Company had a 20% interest in Kings Hill Unit Trust, an entity engaged in the ownership of office properties in the County of Kent, United Kingdom. This joint venture is part of the Company's United Kingdom reportable segment. As of December 31, 2017 , the joint venture owned 14 office properties totaling 489,000 square feet. A cash sweep of net cash flow is required to be implemented under the mortgage loan encumbering such properties until such time as a loan-to-value milestone is satisfied. In lieu thereof, the joint venture and the bank have agreed to a partial pay down of the mortgage loan in 2018. The Company had notes receivable from Kings Hill Unit Trust for an aggregate of $4.7 million and $4.1 million as of December 31, 2017 and 2016 , respectively. The note receivable bears interest at a rate of 10% and is due in November 2020. These related party receivables are reflected in investments in and advances to unconsolidated joint ventures in the Company's consolidated balance sheets. The Company had a receivable from Kings Hill Unit Trust for $122,000 and $121,000 as of December 31, 2017 and 2016, respectively. This related party receivable is reflected as prepaid expenses and other assets in the Company's consolidated balance sheets. The Company recognized $302,000 , $293,000 and $304,000 in fees for services during the years ended December 31, 2017 , 2016 and 2015 , respectively. Liberty Illinois, LP As of December 31, 2017 , the Company had a 25% interest in Liberty Illinois, LP, an entity primarily engaged in the ownership of industrial properties in Illinois. This joint venture is part of the Company's Chicago/Minneapolis reportable segment. As of December 31, 2017 , the joint venture owned 12 industrial properties totaling 4.9 million square feet and 248 acres of developable land. During the year ended December 31, 2016, the joint venture sold four properties containing 636,000 square feet for $32.5 million . The Company's share of gain on property dispositions was $1.0 million and is included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. The Company had a receivable from Liberty Illinois, LP for $5,000 and $132,000 as of December 31, 2017 and 2016, respectively. This related party receivable is reflected as prepaid expenses and other assets in the Company's consolidated balance sheets. The Company recognized $0.9 million , $1.0 million and $1.3 million in fees for services during the years ended December 31, 2017 , 2016 and 2015 , respectively. Liberty Washington, LP As of December 31, 2017 , the Company had a 25% interest in Liberty Washington, LP, an entity engaged in the ownership of office properties in Washington, D.C (and formerly Northern Virginia). This joint venture's properties are part of the Company's DC Metro reportable segment. During the year ended December 31, 2016, the Company divested itself of properties in this joint venture that were located in Northern Virginia (see below). These properties had been part of a reportable segment classified as Other. As of December 31, 2017 , the joint venture owned two office properties totaling 451,000 square feet. During the year ended December 31, 2017 , the Company concluded that a property owned by this joint venture had an indicator of impairment as it anticipated a shortened hold period, major lease expiration and significant capital investment. The joint venture recognized impairment charges of $15.9 million . The Company's share of this impairment charge was $4.0 million . The impairment charges were related to the Company's DC Metro reportable segment and the Company's share was included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. The Company determined these impairments based on estimated future discounted cash flows. This is a Level 3 fair value calculation. During the year ended December 31, 2016, the joint venture sold 12 properties located in Northern Virginia containing 1.2 million square feet and 6.0 acres of land for $187.2 million . During the year ended December 31, 2016, due to adverse conditions in the Northern Virginia office market, six properties containing 698,000 square feet were transferred to mortgage lenders in satisfaction of an aggregate of $112.5 million in nonrecourse mortgage loans that were secured by the properties. The book values of these properties had been written down to fair value in prior periods. Because these loans were nonrecourse, the Company believes that the transfers described above will not have an ongoing effect on its operating results or financial condition. The Company's share of gain from property dispositions and extinguishment of debt is included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. During the year ended December 31, 2016, the Company's share of gain from extinguishment of debt was $4.2 million . The Company's share of gain on property dispositions for the year ended December 31, 2016 was $6.0 million . During the year ended December 31, 2015, the joint venture realized gross proceeds of $5.0 million from the sale of one property totaling 80,000 square feet. The Company had a receivable from Liberty Washington, LP for $316,000 and $322,000 as of December 31, 2017 and 2016 , respectively. This related party receivable is reflected as prepaid expenses and other assets in the Company's consolidated balance sheets. During the year ended December 31, 2015, the Company concluded that certain of the properties owned by this joint venture were impaired and the joint venture recognized impairment charges of $56.8 million . The Company's share of this impairment charge was $11.5 million . The impairment charges were related to the Company's Northern Virginia reportable segment and the Company's share was included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. The Company determined these impairments based on third party offer prices. This is a Level 2 fair value calculation. The Company recognized $1.1 million , $2.0 million and $4.8 million in fees for services during the years ended December 31, 2017 , 2016 and 2015 , respectively. Liberty/Comcast 1701 JFK Boulevard, LP As of December 31, 2017 , the Company had a 20% interest in Liberty/Comcast 1701 JFK Boulevard LP ("Liberty/Comcast"), formerly known as Liberty/Commerz 1701 JFK Boulevard, LP, an entity engaged in the ownership of a 1.25 million square foot office tower in Philadelphia, Pennsylvania. During the year ended December 31, 2015, the limited partnership agreement was amended to replace the general partner and admit a new general partner. As a result of this amendment the Company determined that this joint venture is a VIE. Because the Company and its third party partner share control of the joint venture as both parties have the power to direct its activities, the Company determined that it is not the primary beneficiary and that the equity method of accounting is appropriate. This joint venture is part of the Company's Philadelphia reportable segment. The Company had a payable to this joint venture for $59,000 as of both December 31, 2017 and 2016 . This related party payable is reflected in investments in and advances to unconsolidated joint ventures in the Company's consolidated balance sheets. The Company had a receivable from this joint venture for $272,000 and $401,000 as of December 31, 2017 and 2016 , respectively. This related party receivable is reflected in prepaid expenses and other assets in the Company's consolidated balance sheets. The Company recognized $2.7 million , $2.7 million and $2.7 million in fees for services during the years ended December 31, 2017 , 2016 and 2015 , respectively. Subsequent to December 31, 2017, the joint venture paid in full the $305.2 million mortgage loan on the office building. This was funded through loans from the joint venture partners in proportion to their ownership interests. 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 will include 1.3 million square feet of leasable office space (the "Office") and a 217 -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 $953.7 million . The Company's investment in the project is expected to be approximately $190.7 million with 20% ownership interests in both joint ventures. As of December 31, 2017 , the Company's investment in these joint ventures was $177.8 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. During the year ended December 31, 2017, the joint venture for Liberty Property 18th & Arch brought into service 1.1 million square feet of office space representing a Total Investment of $599.6 million . The remaining 250,000 square feet of office space and the 217 -room Four Seasons hotel representing an aggregate Total Investment of $354.1 million continued to be developed by the joint ventures as of December 31, 2017. 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 to construct the Project. The Company is accounting for the development of the Project using the percentage of completion method. The Company recognized a loss of $3.5 million for the year ended December 31, 2017, and income of $0.6 million and $1.6 million for the years ended December 31, 2016 and 2015, respectively, in developer service fee income, net of developer service fee expense and other related expenses. The Company believes it has applied reasonable estimates and judgments in determining the amount of estimated development costs for the Project. The Company has recently been notified, however, that there are additional construction costs in connection with the Project. Until such time as the Company receives appropriate information concerning the amount and nature of these additional costs and has an opportunity to investigate them, it is not possible to estimate the amount of possible additional costs, if any, that the Company may incur in connection with its guarantee beyond the obligations of the contractor under its guaranteed maximum price contracts. The Company had a receivable from this joint venture of $466,000 and $1.3 million as of December 31, 2017 and 2016, respectively. This receivable is included in prepaid expenses and other assets in the Company's consolidated balance sheets. During the year ended December 31, 2016, the joint venture sold three residential condominium units located on the 45 th floor containing 14,700 square feet for $14.3 million . The Company's share of gain on property dispositions was $0.3 million and is included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. The Company will manage and lease the Office and Four Seasons Hotels Limited will manage the Hotel. The Company recognized $230,000 , $75,000 and $75,000 in related fee income during the years ended December 31, 2017 , 2016 and 2015 , respectively. Other Joint Ventures As of December 31, 2017 , the Company had a 50% ownership interest in three additional unconsolidated joint ventures. One of these joint ventures has seven operating properties and an investment in land held for development and is part of the Company's Florida reportable segment. One of these joint ventures sold its real estate assets in 2016 and was part of the Company's United Kingdom reportable segment. The sales price was $13.7 million and the Company's share of the loss on sale was $6,000 . This amount is included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. One joint venture has a leasehold interest and does not operate or own operating properties and is part of the Company's United Kingdom reportable segment. The Company had a note payable due to this joint venture of $2.5 million and $2.3 million as of December 31, 2017 and 2016 , respectively. The note payable is interest free and is due upon written notice from the joint venture. This related party payable is reflected in investments in and advances to unconsolidated joint ventures in the Company's consolidated balance sheets. Additionally, as of December 31, 2017 , the Company had a 20% ownership interest in an unconsolidated joint venture that acquired one redevelopment property comprising 48,000 square feet for $15.0 million . This joint venture also owns one acre of developable land and is part of the Company's Philadelphia reportable segment. The Company's share of each of the joint venture's earnings is included in equity in earnings of unconsolidated joint ventures in the accompanying consolidated statements of comprehensive income. Summary Financial Data The condensed balance sheets as of December 31, 2017 and 2016 and condensed statements of operations for the years ended December 31, 2017 , 2016 and 2015 for Liberty Venture I LP, Kings Hill Unit Trust, Liberty Illinois, LP, Liberty Washington LP, Liberty/Comcast, Liberty Property 18th & Arch, and the other unconsolidated joint ventures are as follows (in thousands): Condensed Balance Sheets: December 31, 2017 Liberty Kings Hill Liberty Liberty Liberty/ Liberty Property Venture I, LP Unit Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other Total Real estate assets $ 229,600 $ 152,998 $ 252,593 $ 274,847 $ 496,210 $ 551,874 $ 98,589 $ 2,056,711 Accumulated depreciation (48,629 ) (30,028 ) (57,444 ) (49,106 ) (138,943 ) (4,070 ) (10,995 ) (339,215 ) Real estate assets, net 180,971 122,970 195,149 225,741 357,267 547,804 87,594 1,717,496 Development in progress 18,337 — — — — 289,767 — 308,104 Land held for development — — 33,500 — — — 41,075 74,575 Other assets 20,722 10,957 16,337 18,566 49,755 98,191 24,263 238,791 Total assets $ 220,030 $ 133,927 $ 244,986 $ 244,307 $ 407,022 $ 935,762 $ 152,932 $ 2,338,966 Debt $ 166,295 $ 92,131 $ 138,869 $ 102,624 $ 305,223 $ — $ 63,999 $ 869,141 Other liabilities 4,117 28,056 7,548 4,954 9,488 102,982 8,420 165,565 Equity 49,618 13,740 98,569 136,729 92,311 832,780 80,513 1,304,260 Total liabilities and equity $ 220,030 $ 133,927 $ 244,986 $ 244,307 $ 407,022 $ 935,762 $ 152,932 $ 2,338,966 Company's net investment in unconsolidated joint ventures (1) $ 10,425 $ 6,100 $ 14,980 $ 34,107 $ 17,307 $ 177,843 $ 27,694 $ 288,456 December 31, 2016 Liberty Kings Hill Liberty Liberty Liberty/ Liberty Property Venture I, LP Unit Trust Illinois, LP Washington, LP Comcast 18th and Arch (2) Other Total Real estate assets $ 226,313 $ 137,960 $ 251,765 $ 289,627 $ 495,842 $ — $ 71,722 $ 1,473,229 Accumulated depreciation (42,779 ) (26,872 ) (51,901 ) (44,235 ) (125,014 ) — (9,702 ) (300,503 ) Real estate assets, net 183,534 111,088 199,864 245,392 370,828 — 62,020 1,172,726 Development in progress 6,886 — — — — 671,032 — 677,918 Land held for development — — 31,567 — — — 42,259 73,826 Other assets 23,494 9,603 19,036 18,749 48,074 52,053 29,654 200,663 Total assets $ 213,914 $ 120,691 $ 250,467 $ 264,141 $ 418,902 $ 723,085 $ 133,933 $ 2,125,133 Debt $ 154,386 $ 83,846 $ 137,294 $ 103,667 $ 309,475 $ — $ 57,660 $ 846,328 Other liabilities 6,673 24,513 8,433 4,385 9,964 95,574 17,155 166,697 Equity 52,855 12,332 104,740 156,089 99,463 627,511 59,118 1,112,108 Total liabilities and equity $ 213,914 $ 120,691 $ 250,467 $ 264,141 $ 418,902 $ 723,085 $ 133,933 $ 2,125,133 Company's net investment in unconsolidated joint ventures (1) $ 11,175 $ 5,349 $ 15,339 $ 38,863 $ 18,688 $ 132,952 $ 22,712 $ 245,078 Condensed Statements of Operations: Year Ended December 31, 2017 Liberty Kings Hill Unit Liberty Liberty Liberty/ Liberty Property Venture I, LP Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other (3) Total Total revenue $ 31,079 $ 12,976 $ 23,711 $ 25,439 $ 65,372 $ 16,544 $ 11,118 $ 186,239 Operating expense 8,101 4,756 7,989 9,147 26,474 3,417 3,365 63,249 Net operating income 22,978 8,220 15,722 16,292 38,898 13,127 7,753 122,990 Interest (5,801 ) (2,329 ) (5,882 ) (4,065 ) (19,411 ) — (2,807 ) (40,295 ) Depreciation and amortization (7,598 ) (3,238 ) (6,918 ) (5,926 ) (14,485 ) (4,077 ) (2,124 ) (44,366 ) Other income (expense) (100 ) (4 ) (71 ) (65 ) (325 ) (547 ) 15,549 14,437 Gain (loss) on sale/impairment — — — (15,910 ) — 30 — (15,880 ) Net income (loss) $ 9,479 $ 2,649 $ 2,851 $ (9,674 ) $ 4,677 $ 8,533 $ 18,371 $ 36,886 Company's equity in earnings (loss) of unconsolidated joint ventures $ 2,914 $ 660 $ 2,118 $ (1,941 ) $ 1,659 $ 1,782 $ 9,963 $ 17,155 Year Ended December 31, 2016 Liberty Kings Hill Unit Liberty Liberty Liberty/ Liberty Property Venture I, LP Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other (3) Total Total revenue $ 25,149 $ 11,926 $ 26,599 $ 39,727 $ 65,587 $ — $ 9,888 $ 178,876 Operating expense 6,835 4,854 9,961 15,935 26,761 280 2,801 67,427 Net operating income 18,314 7,072 16,638 23,792 38,826 (280 ) 7,087 111,449 Interest (4,182 ) (2,554 ) (7,243 ) (10,866 ) (19,737 ) — (2,462 ) (47,044 ) Depreciation and amortization (6,375 ) (3,557 ) (7,589 ) (10,750 ) (14,513 ) — (1,925 ) (44,709 ) Other income (expense) 50 (77 ) 64 257 (213 ) 1,270 7,123 8,474 Gain (loss) on sale/impairment — — 4,068 40,943 — — (11 ) 45,000 Net income $ 7,807 $ 884 $ 5,938 $ 43,376 $ 4,363 $ 990 $ 9,812 $ 73,170 Company's equity in earnings (loss) of unconsolidated joint ventures $ 2,332 $ 275 $ 2,065 $ 10,857 $ 1,594 $ 213 $ 4,634 $ 21,970 Year Ended December 31, 2015 Liberty Kings Hill Unit Liberty Liberty Liberty/ Liberty Property Venture I, LP Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other (3) Total Total revenue $ 23,708 $ 12,602 $ 26,085 $ 71,101 $ 68,444 $ — $ 9,387 $ 211,327 Operating expense 7,977 5,261 9,303 27,384 29,692 221 2,727 82,565 Net operating income 15,731 7,341 16,782 43,717 38,752 (221 ) 6,660 128,762 Interest (5,415 ) (6,116 ) (8,441 ) (17,353 ) (19,936 ) — (2,248 ) (59,509 ) Depreciation and amortization (6,399 ) (3,954 ) (7,406 ) (20,725 ) (14,442 ) — (1,840 ) (54,766 ) Other income (expense) 68 45,604 29 531 (227 ) 30 9,925 55,960 Income (loss) from discontinued operations 760 — — (56,792 ) — — — (56,032 ) Net income (loss) $ 4,745 $ 42,875 $ 964 $ (50,622 ) $ 4,147 $ (191 ) $ 12,497 $ 14,415 Company's equity in earnings (loss) of unconsolidated joint ventures $ 1,540 $ (425 ) $ 807 $ (7,314 ) $ 2,053 $ (29 ) $ 6,517 $ 3,149 (1) Differences between the Company's net investment in unconsolidated joint ventures and its underlying equity in the net assets of the venture are primarily a result of impairments related to the Company's investment in unconsolidated joint ventures, the deferral of gains associated with the sales of properties to joint ventures in which the Company retains an ownership interest and loans made to the joint ventures by the Company. These adjustments have resulted in an aggregate difference reducing the Company's investments in unconsolidated joint ventures by $3.0 million and $1.4 million as of December 31, 2017 and 2016 , respectively. Differences between historical cost basis and the basis reflected at the joint venture level (other than loans) are typically depreciated over the life of the related asset. (2) Represents the combined results of two joint ventures related to the property at 18th and Arch Streets, Philadelphia. (3) Other income/(expense) for this group of joint ventures reflects gains related to the sales of land leasehold interests totaling $16.0 million , $7.1 million and $9.9 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Deferred Financing and Leasing

Deferred Financing and Leasing Costs	12 Months Ended
	Dec. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Deferred Financing and Leasing Costs	DEFERRED FINANCING AND LEASING COSTS Deferred financing and leasing costs were comprised of the following as of December 31, 2017 and 2016 (in thousands): December 31, 2017 2016 Deferred financing costs $ 17,044 $ 11,917 Deferred leasing costs 198,767 179,161 Market value intangible 18,802 19,451 Origination value intangible 90,116 83,485 324,729 294,014 Accumulated amortization: Deferred financing costs 11,002 10,152 Deferred leasing costs 80,434 70,842 Market value intangible 14,324 12,625 Origination value intangible 59,719 53,357 165,479 146,976 Deferred financing and leasing costs, net $ 159,250 $ 147,038 Amortization of deferred financing costs was $3.8 million , $4.0 million and $4.4 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Amortization of deferred leasing costs and origination value intangible was $31.6 million , $37.1 million and $44.2 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. As of December 31, 2017 , the remaining weighted-average amortization period was 3.2 years for market value intangible and 5.5 years for origination value intangible. The table above includes market value intangible assets. There were also $9.6 million and $4.4 million of unamortized market value intangible liabilities as of December 31, 2017 and 2016 , respectively. These liabilities are included as other liabilities in the accompanying consolidated balance sheets of the Company. Amortization of the aggregate asset and liability for market value intangible was an expense of $1.3 million , $1.6 million and $1.9 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. These amounts were included as a decrease in rental revenue in the accompanying consolidated statements of comprehensive income. The aggregate amortization of net market value intangible assets and liabilities is a decrease (increase) in rental revenue over the next five years and thereafter as follows (in thousands): 2018 $ 242 2019 (265 ) 2020 (858 ) 2021 (891 ) 2022 (762 ) Thereafter (2,637 ) Total $ (5,171 ) The aggregate amortization expense for origination value intangible asset for the next five years and thereafter is as follows (in thousands): 2018 $ 9,748 2019 6,437 2020 3,664 2021 2,839 2022 2,158 Thereafter 5,551 Total $ 30,397

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Indebtedness	INDEBTEDNESS Overview Indebtedness consists of mortgage loans, unsecured notes, and borrowings under the Company's Credit Facilities (see below). The weighted average interest rates for the years ended December 31, 2017 , 2016 and 2015 were 3.8% , 4.3% and 4.6% , respectively. Interest costs during the years ended December 31, 2017 , 2016 and 2015 in the amount of $21.0 million , $24.1 million and $16.7 million , respectively, were capitalized. Cash paid for interest for the years ended December 31, 2017 , 2016 and 2015 was $111.8 million , $142.7 million and $149.6 million , respectively. The Company is subject to financial covenants contained in some of its debt agreements, the most restrictive of which are detailed below under the heading "Credit Facilities." As of December 31, 2017 , the Company was in compliance with all financial and non-financial covenants. The scheduled principal amortization and maturities of the Company's mortgage loans, unsecured notes outstanding and the Credit Facilities (as defined below) and the related weighted average interest rates at December 31, 2017 are as follows (in thousands, except percentages): Weighted Mortgages Average Principal Principal Unsecured Credit Interest Amortization Maturities Notes Facilities Total Rate 2018 $ 6,565 $ 26,995 $ — $ — $ 33,560 3.20 % 2019 6,504 50,043 — — 56,547 3.95 % 2020 3,539 67,361 350,000 — 420,900 4.66 % 2021 2,504 65,009 — 358,939 426,452 2.62 % 2022 2,172 — 400,000 — 402,172 4.13 % 2023 2,281 — 300,000 — 302,281 3.39 % 2024 2,395 — 450,000 — 452,395 4.40 % 2025 2,503 — 400,000 — 402,503 3.76 % 2026 2,494 1,946 400,000 — 404,440 3.26 % 2027 and thereafter 19,800 — — — 19,800 4.84 % Subtotal $ 50,757 $ 211,354 $ 2,300,000 $ 358,939 $ 2,921,050 3.77 % Reconciling items (1) 4,982 — (16,487 ) — (11,505 ) Total for consolidated balance sheet $ 55,739 $ 211,354 $ 2,283,513 $ 358,939 $ 2,909,545 (1) Includes deferred financing costs, premium/discount and market adjustments. Mortgage Loans and Unsecured Notes Mortgage loans with maturities ranging from 2018 to 2033 were collateralized by and in some instances cross-collateralized by properties with a net book value of $491.7 million as of December 31, 2017 . The interest rates on $2,562.1 million of mortgage loans (including $96.2 million fixed via a swap arrangement - see Footnote 20 - Derivative Instruments) and unsecured notes are fixed and range from 3.0% to 4.8% . The weighted average remaining term for the mortgage loans and unsecured notes is 5.5 years. Credit Facilities The Company has maintained an unsecured credit facility throughout 2015 , 2016 and 2017 . During that period the Company has replaced, restated and amended its credit facility. This activity has resulted in changes to borrowing capacity, due dates, borrowing costs and covenant calculations. As replaced, restated and amended these credit facilities are referred to below as the "Credit Facility." The Credit Facility includes a revolving credit facility for aggregate borrowings of $800 million and a delayed draw term loan facility for aggregate borrowings of $100 million . The interest rate on borrowings under the Credit Facility fluctuates based upon ratings from Moody’s Investors Service, Inc., Standard and Poor’s Ratings Group and Fitch, Inc. Based on the Company's ratings as of December 31, 2017, borrowings under the revolving credit facility currently bear interest at LIBOR plus 0.875% and the delayed draw term loan facility bear interest at LIBOR plus 0.95% . The Credit Facility also contains an annual facility fee, the rate of which is currently 0.15% of the aggregate loan commitments. The Credit Facility provides for the interest rate and facility fee rate to be adjusted up or down based on changes in the credit ratings on the Company's senior unsecured debt. The Credit Facility expires in October 2021 and has two six -month extensions at the Company's option, subject to the payment of a stated fee. The Credit Facility contains a competitive bid option, whereby participating lenders bid on the interest rate to be charged. This feature is available for up to 50% of the amount of the revolving facility. There were $355.0 million borrowings outstanding under the revolving credit facility and no borrowings under the delayed draw term loan facility as of December 31, 2017. As of December 31, 2017, letters of credit to third parties totaling $5.1 million had been issued for the account of the Company under this Credit Facility. The Credit Facility contains financial covenants, certain of which are set forth below: • total debt to total assets may not exceed 0.60 : 1 ; • adjusted earnings before interest, taxes, depreciation and amortization to fixed charges may not be less than 1.50 :1; • unsecured debt to unencumbered asset value must equal or be less than 60% • secured debt to total asset value must equal or be less than 35% ; and • unencumbered adjusted net operating income to unsecured interest expense must equal or exceed 175% . In October 2017, the Company entered into a credit agreement for a working capital facility for aggregate borrowings of up to $30 million . This facility has the same maturity date, facility fee and interest rate borrowing terms as the revolving credit facility described above. There were $3.9 million in borrowings outstanding under the working capital facility as of December 31, 2017. Activity In September 2016, the Company issued $400 million of 3.25% senior unsecured notes due 2026. The Company used a substantial portion of the net proceeds from these notes to prepay its 5.5% Senior Notes due December 2016 in the amount of $300 million . This prepayment resulted in a $3.8 million loss on debt extinguishment. In November 2016, the Company used cash generated by the sale of properties (see Note 6) to prepay its 6.625% senior notes due October 2017 in the amount of $296.5 million and its 7.5% medium term notes due January 2018 in the amount of $100.0 million . This prepayment resulted in a $23.6 million loss on debt extinguishment. In October 2017, the Company replaced its existing $800 million Credit Facility with a new $800 million revolving credit facility and a $100 million delayed draw term loan facility. Additionally, the Company entered into a working capital facility for aggregate borrowings of up to $30 million .

Leasing Activity

Leasing Activity	12 Months Ended
	Dec. 31, 2017
Operating Leases, Future Minimum Payments Receivable [Abstract]
Leasing Activity	LEASING ACTIVITY Future minimum rental payments due from tenants under noncancelable operating leases as of December 31, 2017 are as follows (in thousands): 2018 $ 493,131 2019 462,698 2020 394,462 2021 334,969 2022 273,715 Thereafter 1,102,030 Total $ 3,061,005 In addition to minimum rental payments, most leases require the tenants to pay for their pro rata share of specified operating expenses. These payments are included as operating expense reimbursement in the accompanying consolidated statements of comprehensive income.

Noncontrolling Interest - Opera

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units	12 Months Ended
	Dec. 31, 2017
Noncontrolling Interest - Operating Partnership / LImited Partners' Equity - Preferred Units [Abstract]
Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units	NONCONTROLLING INTEREST - OPERATING PARTNERSHIP / LIMITED PARTNERS' EQUITY - PREFERRED UNITS As of December 31, 2017 , the Company had outstanding the following cumulative preferred units of the Operating Partnership: ISSUE AMOUNT UNITS LIQUIDATION PREFERENCE DIVIDEND RATE (in 000’s) Series I-2 $ 7,537 301 $25 6.25 % The preferred units are putable at the holder's option at any time and are callable at the Operating Partnership's option after a stated period of time for cash. Preferred distributions related to the Series I units were $472,000 for each of the years ended December 31, 2017 , 2016 and 2015 .

Shareholders' Equity - Trust

Shareholders' Equity - Trust	12 Months Ended
	Dec. 31, 2017
Shareholders' Equity [Abstract]
Shareholders' Equity - Trust	SHAREHOLDERS' EQUITY - TRUST Common Shares The Company paid to holders of its common shares and holders of its common units distributions of $252.3 million , $285.9 million and $289.3 million during the years ended December 31, 2017 , 2016 and 2015 , respectively. On a per share basis, the Company paid common share and common unit distributions of $1.675 during the year ended December 31, 2017 and $1.90 during each of the years ended December 31, 2016 and 2015 . The following unaudited table summarizes the taxability of common share distributions (taxability for 2017 is estimated): 2017 2016 2015 Ordinary dividend $ 1.5369 $ 1.0319 $ 1.4348 Qualified dividend 0.0150 0.0013 — Capital gain - 20% 0.0482 — 0.1112 IRC Sec 1250 unrecaptured gain - 25% 0.0749 0.6176 0.3372 Return of capital — 0.2492 0.0168 Total $ 1.6750 $ 1.9000 $ 1.9000 The Company's tax return for the year ended December 31, 2017 has not been filed. The taxability information presented for the 2017 distributions is based upon the best available data at the time of this filing. In addition, certain of the Company's prior federal income tax returns may still be subject to examination by various taxing authorities. Because the application of tax laws and regulations is susceptible to varying interpretations, the taxability of distributions being reported here could be changed at a later date as a result of an examination and final determination by such taxing authorities. Common units The common units of the Operating Partnership not held by the Trust outstanding as of December 31, 2017 have the same economic characteristics as common shares of the Trust. The 3,520,205 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 3,520,205 outstanding common units based on the closing price of the common shares of the Company at December 31, 2017 was $ 151.4 million . No common units were issued in connection with acquisitions during 2017 , 2016 or 2015 . Dividend Reinvestment and Share Purchase Plan The Company has a Dividend Reinvestment and Share Purchase Plan under which holders of common shares may elect to automatically reinvest their distributions in additional common shares and may make optional cash payments for additional common shares. The Company may issue additional common shares or repurchase common shares in the open market for purposes of satisfying its obligations under the Dividend Reinvestment and Share Purchase Plan. During the years ended December 31, 2017 , 2016 , and 2015 , 42,366 , 56,426 , and 1,036,437 common shares, respectively, were issued through the Dividend Reinvestment and Share Purchase Plan. The Company used the proceeds to pay down outstanding borrowings under the Company's existing credit facility and for general corporate purposes. Continuous Equity Offering The Company has a continuous equity offering program in place for up to $200 million of equity, of which $125.0 million remains available. The Company did no t sell any common shares pursuant to its continuous equity offering program during 2017, 2016 or 2015. Noncontrolling Interest - Consolidated Joint Ventures Noncontrolling interest - consolidated joint ventures includes third-party ownership interests in consolidated joint venture investments. Share Repurchase In August 2015, the Company’s Board of Trustees authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common shares. Purchases made pursuant to the program will be made in either the open market or in privately negotiated transactions from time to time as permitted by securities laws and other legal requirements. During the years ended December 31, 2016 and 2015, the Company purchased an aggregate of 1.4 million and 2.3 million common shares, respectively, for $40.9 million and $71.8 million , respectively, as part of the share repurchase plan. There were no share repurchases under this plan in 2017. In September 2017, the Company's Board of Trustees re-authorized this plan for up to $250 million of the Company's outstanding shares. No purchases have been made as of December 31, 2017 under this re-authorized plan.

Owners' Equity - Operating Part

Owners' Equity - Operating Partnership	12 Months Ended
	Dec. 31, 2017
Liberty Property Limited Partnership [Member]
Class of Stock [Line Items]
Owners' Equity - Operating Partnership	OWNERS' EQUITY - OPERATING PARTNERSHIP Common Units General and limited partners' equity - common units relates to limited partnership interests of the Operating Partnership issued in connection with the formation of the Operating Partnership and certain subsequent acquisitions. The common units outstanding as of December 31, 2017 have the same economic characteristics as common shares of the Trust. The 3,520,205 outstanding common units are the limited partners' equity - common units held by persons and entities other than the Trust, the general partner of the Operating Partnership, which holds a number of common units equal to the number of outstanding common shares of beneficial interest. Both the common units held by the Trust and the common units held by persons and entities other than the Trust are counted in the weighted average number of common units outstanding during any given period. The 3,520,205 outstanding common units share proportionately in the net income or loss and in any distributions of the Operating Partnership and are exchangeable into the same number of common shares of the Trust. The market value of the 3,520,205 outstanding common units at December 31, 2017 based on the closing price of the common shares of the Company at December 31, 2017 was $ 151.4 million . No common units were issued in connection with acquisitions during 2017 , 2016 or 2015 . Dividend Reinvestment and Share Purchase Plan The Company has a Dividend Reinvestment and Share Purchase Plan under which holders of common shares may elect to automatically reinvest their distributions in additional common shares and may make optional cash payments for additional common shares. The Company may issue additional common shares or repurchase common shares in the open market for purposes of satisfying its obligations under the Dividend Reinvestment and Share Purchase Plan. During the years ended December 31, 2017 , 2016 , and 2015 , 42,366 , 56,426 , and 1,036,437 common shares, respectively, were issued through the Dividend Reinvestment and Share Purchase Plan. A corresponding number of common units were issued by the Operating Partnership. The Company used the proceeds to pay down outstanding borrowings under the Company's existing credit facility and for general corporate purposes. Noncontrolling Interest - Consolidated Joint Ventures Noncontrolling interest - consolidated joint ventures includes third-party ownership interests in consolidated joint venture investments. Share Repurchase In August 2015, the Company’s Board of Trustees authorized a share repurchase plan under which the Company may purchase up to $250 million of the Company’s outstanding common shares. Purchases made pursuant to the program will be made in either the open market or in privately negotiated transactions from time to time as permitted by securities laws and other legal requirements. During the years ended December 31, 2016 and 2015, the Company purchased an aggregate of 1.4 million and 2.3 million common shares, respectively, for $40.9 million and $71.8 million , respectively, as part of the share repurchase plan. In connection with these repurchases, an equal number of common units were repurchased by the Operating Partnership from the Trust. There were no share repurchases under this plan in 2017. In September 2017, the Company's Board of Trustees re-authorized this plan for up to $250 million of the Company's outstanding shares. No purchases have been made as of December 31, 2017 under this re-authorized plan.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Employee Benefit Plans [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS The Company maintains a 401(k) plan for the benefit of its employees. The Company matches the employees' contributions up to 3% of the employees' salary and may also make annual discretionary contributions. Total 401(k) expense recognized by the Company was $755,000 , $874,000 and $1,038,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2017
Share-based Compensation [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION Compensation Plans The Company has a share-based compensation plan (the "Plan") which is utilized to compensate key employees and non-employee trustees. The plan was last amended and restated in 2014. Pursuant to the Plan, grants of stock options, restricted shares and restricted stock units have been made. The Company has authorized the grant of shares and options under the Plan of up to 21.1 million common shares of the Company. The Company capitalized $1.1 million , $1.2 million and $0.9 million in share-based compensation costs for the years ended December 31, 2017, 2016, and 2015, respectively. Options All options granted have a 10 -year term and most options vest and are expensed over a 3 -year period, with options to purchase up to 20% of the shares exercisable after the first anniversary, up to 50% after the second anniversary and 100% after the third anniversary of the date of grant. Share-based compensation cost related to options for the years ended December 31, 2017 , 2016 and 2015 was $73,000 , $0.2 million and $1.5 million , respectively. The fair value of share option awards is estimated on the date of the grant using the Black-Scholes option valuation model. The following weighted-average assumptions were utilized in calculating the fair value of options granted during the periods indicated: Year Ended December 31, 2015 Risk-free interest rate 1.8% Dividend yield 5.2% Historical volatility factor 0.24 Weighted-average expected life 7 years The historical volatility factor is based on the Company's historical monthly share prices. The weighted-average expected life is based on the contractual term of the options as well as the historical periods held before exercise. A summary of the Company's share option activity and related information for the year ended December 31, 2017 follows: Options (000s) Weighted Average Exercise Price Outstanding January 1, 2017 1,927 $ 36.02 Exercised (193 ) 34.72 Forfeited (153 ) 48.58 Outstanding December 31, 2017 1,581 $ 34.97 Exercisable at December 31, 2017 1,417 $ 34.95 The weighted average fair value of options granted during the year ended December 31, 2015 was $4.11 . No new options were granted during the years ended December 31, 2017 and 2016. Exercise prices for options outstanding as of December 31, 2017 ranged from $20.32 to $39.59 . At December 31, 2017 , the weighted average remaining contractual life of the options outstanding and exercisable was 4.7 years and 4.4 years, respectively. During the years ended December 31, 2017 , 2016 and 2015 , the total intrinsic value of share options exercised (the difference between the market price at exercise and the price paid by the individual to exercise the option) was $1.4 million , $3.5 million and $0.4 million , respectively. As of December 31, 2017 , 1.4 million options outstanding and exercisable had an exercise price lower than the closing price of the Company's common shares. The aggregate intrinsic value of these options was $11.4 million at that date. The total cash received from the exercise of options for the years ended December 31, 2017 , 2016 and 2015 was $6.7 million , $14.4 million and $2.1 million , respectively. As of December 31, 2017 , there were no unrecognized compensation costs related to nonvested options granted under the Plan. Long Term Incentive Shares ("LTI") During January 2017, 2016 and 2015, restricted LTI share grants made under the Plan were valued at the grant date fair value, which is the market price of the underlying common shares. LTI share grants after February 2017 were valued at the average closing price of the Company's shares for the trading days included within the 30-calendar-day period prior to and including the date of grant. The shares vest over either a 3 -year or 5 -year period beginning with the first anniversary of the grant and subject to certain accelerated vesting due to the age and years of service of certain employees. During 2017 , 2016 and 2015 , the Company granted restricted stock units to the executive officers pursuant to the Plan. For the chief executive officer's award, a portion of the restricted stock units will vest up to 272% at the end of a 3 -year period. For the other executives, a portion of the restricted stock units will vest up to 200% at the end of a 3 -year period. A portion ("First Portion") of the award vests based on how the Company's total return compares to the average total returns of a selected group of peer companies. The grant date fair value of the First Portion was calculated based on a Monte Carlo simulation model and was determined to be 132% , 174% and 110% of the market value of a common share as of the grant date ("Market Value") for the chief executive officer and 105% , 136% and 90% of the Market Value for the other executives for the 2017, 2016 and 2015 grants, respectively. A separate grant was made to the Company's Chief Financial Officer in 2016 when he joined the Company, and the grant date fair value of this award's First Portion was determined to be 160% of the Market Value as of the grant date. The First Portion is amortized over the respective 3 -year period subject to certain accelerated vesting due to the age and years of service of certain executive officers. For the 2015 grant, another portion of the award vests based on the Company's funds from operations. Targets are established for each of the 3 years in the relevant award period. Depending on how each year's performance compares to the projected performance for that year, the restricted stock units are deemed earned and will vest at the end of the award period. The fair value of this portion is based on the market value of a common share as of the grant date and is being amortized to expense during the period from grant date to the vesting dates, adjusting for the expected level of vesting that is anticipated to occur at those dates also subject to certain accelerated vesting provisions as described above. This component of the award was discontinued with the 2016 award. For the 2016 and 2017 awards, the second portion of the award for the executive officers, other than the Chief Financial Officer's 2016 award, vests at the end of three years based on continued employment. The second portion of the Chief Financial Officer's award vests ratably over three years. For the 2017 award, the second portion of the award for the executive officers vests at the end of three years based on continued employment. The key assumptions used in the Monte Carlo simulations are as follows: Year Ended December 31, 2017 2016 2015 Risk-free interest rate 1.43% 1.01% 0.99% Volatility 20% 19% 17% The volatility factor is based on the Company's historical daily share prices. Share-based compensation cost related to restricted LTI share grants for the years ended December 31, 2017 , 2016 and 2015 was $11.3 million , $12.2 million and $10.0 million , respectively. The Company's restricted LTI share activity for the year ended December 31, 2017 is as follows: Shares (000s) Weighted Avg. Grant Date Fair value Nonvested at January 1, 2017 812 $ 34.71 Granted 310 39.93 Vested (330 ) 35.57 Forfeited (17 ) 35.07 Nonvested at December 31, 2017 775 $ 36.43 The weighted average fair value of restricted shares granted during the years ended December 31, 2017 , 2016 and 2015 was $39.93 , $32.48 and $35.14 per share, respectively. As of December 31, 2017 , there was $7.6 million of total unrecognized compensation cost related to nonvested shares granted under the Plan. That cost is expected to be recognized over a weighted average period of 1.0 year. The total fair value of restricted shares vested during the years ended December 31, 2017 , 2016 and 2015 was $11.7 million , $9.0 million and $7.4 million , respectively. Bonus Shares During the years ended December 31, 2017 , 2016 and 2015 , the Plan provided that employees of the Company could elect to receive bonuses or commissions in the form of common shares in lieu of cash ("Bonus Shares"). By making such election, the employee received shares equal to 120% of the cash value of the bonus or commission, for up to $50,000 of such bonus or commission, and 100% thereof for amounts exceeding $50,000 , in each case reduced by applicable withholding tax. Bonus Shares issued for the years ended December 31, 2017 , 2016 and 2015 were 51,416 , 140,376 and 111,700 , respectively. Share-based compensation cost related to Bonus Shares for the years ended December 31, 2017 , 2016 and 2015 was $2.0 million , $4.7 million and $3.9 million , respectively. Profit Sharing The Plan provides that employees of the Company, below the officer level, may receive up to 5% of base pay in the form of cash contributions to an investment account depending on Company performance. Compensation cost related to the profit sharing plan for the years ended December 31, 2017 , 2016 and 2015 was $730,000 , $669,000 and $965,000 , respectively. Remaining Reserved Common Shares under the Plan An additional 5,049,687 , 5,264,285 and 5,574,605 common shares were reserved for issuance for future grants under the Plan at December 31, 2017 , 2016 and 2015 , respectively. Employee Share Purchase Plan The Company registered 750,000 common shares under the Securities Act of 1933, as amended, in connection with an employee share purchase plan ("ESPP"). The ESPP enables eligible employees to purchase shares of the Company, in amounts up to 10% of the employee's salary, at a 15% discount to fair market value. There were 10,410 , 11,022 and 13,127 shares issued, in accordance with the ESPP, during the years ended December 31, 2017 , 2016 and 2015 , respectively. Share-based compensation cost related to the ESPP for the years ended December 31, 2017 , 2016 and 2015 was $80,000 , $122,000 and $62,000 , respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Environmental Matters Substantially all of the Company's properties and land were subject to Phase I Environmental Assessments and when appropriate Phase II Environmental Assessments (collectively, the “Environmental Assessments”) obtained in contemplation of their acquisition by the Company or obtained by predecessor owners prior to the sale of the property or land to the Company. The Environmental Assessments did not reveal, nor is the Company aware of, any non-compliance with environmental laws, environmental liability or other environmental claim that the Company believes would likely have a material adverse effect on the Company. Operating Ground Lease Agreements Future minimum rental payments under the terms of all non-cancelable operating ground leases under which the Company is the lessee, as of December 31, 2017 , were as follows (in thousands): Year Amount 2018 $ 1,771 2019 1,766 2020 1,766 2021 1,766 2022 1,720 2023 though 2067 33,160 Total $ 41,949 Operating ground lease expense incurred by the Company during the years December 31, 2017 , 2016 and 2015 totaled $102,000 , $1.0 million and $815,000 , respectively. Legal Matters From time to time, the Company is a party to a variety of legal proceedings, claims and assessments arising in the normal course of business. The Company believes that as of December 31, 2017 there were no legal proceedings, claims or assessments expected to have a material adverse effect on the Company’s business or financial statements. Other As of December 31, 2017 , the Company had letter of credit obligations of $5.1 million related to development requirements. The Company believes that it is remote that there will be a draw upon these letter of credit obligations. As of December 31, 2017 , the Company had 20 buildings under development. These buildings are expected to contain a total of 5.6 million square feet of leaseable space and represent an anticipated aggregate investment of $526.7 million . At December 31, 2017 , Development in Progress totaled $378.5 million . In addition, as of December 31, 2017 , the Company had invested $13.9 million in deferred leasing costs related to these development buildings. As of December 31, 2017 , the Company was committed to $10.5 million in improvements on certain buildings and land parcels. As of December 31, 2017 , the Company was obligated to pay for tenant improvements not yet completed for a maximum of $18.6 million . As of December 31, 2017 , the Company was committed to $60.9 million in future land purchases. The Company expects to complete $32.9 million in future land purchases during the year ended December 31, 2018, with the remaining $28.0 million complete during 2019. In addition, pursuant to a 140,000 square foot lease that the Company has executed, the Company has agreed to start the development of a 140,000 square foot industrial building. Unconsolidated joint ventures in which the Company holds an interest, and, in another case, an unrelated third party, have engaged the Company as the developer of their development properties pursuant to development agreements. Under these agreements, the Company agrees, in consideration for a development fee, to be responsible for all aspects of the development of the properties and to guarantee the timely lien-free completion of construction of the properties as well as the payment, subject to certain exceptions, of any cost overruns incurred in the development of the properties. To mitigate its risk, in each case, the Company entered into guaranteed maximum price contracts with a third party contractor to construct the properties. The Company believes it has applied reasonable estimates and judgments in determining the amount of estimated development costs for the properties. As discussed in Note 7, however, the Company has recently been notified that there are additional construction costs in connection with one of the development properties held in unconsolidated joint ventures in which it holds an interest. Until such time as the Company receives appropriate information concerning the amount and nature of these additional costs and has an opportunity to investigate them, it is not possible to estimate the amount of possible additional costs, if any, that the Company may incur in connection with its guarantee beyond the obligations of the contractor under its guaranteed maximum price contracts. As of December 31, 2017, the Company was developing three buildings for its unconsolidated joint ventures which represented an anticipated aggregate investment by the joint ventures of $375.2 million . As of December 31, 2017, the Company was also committed to approximately $176.9 million in costs related to its agreement to develop, on a fee basis, an office building and infrastructure improvements for American Water Works in Camden, New Jersey. As of December 31, 2017, $102.9 million of these costs had been incurred. 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.

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) A summary of quarterly results of operations for the years ended December 31, 2017 and 2016 follows (in thousands, except for per share data): QUARTER ENDED DEC. 31, SEPT. 30, JUNE 30, MAR. 31, DEC. 31, SEPT. 30, JUNE 30, MAR. 31, 2017 2017 2017 2017 2016 2016 2016 2016 Operating revenue $ 192,803 $ 184,511 $ 174,888 $ 167,576 $ 169,733 $ 181,967 $ 178,033 $ 180,965 Income from continuing operations 114,463 63,968 50,510 42,125 197,038 51,675 48,815 56,626 Discontinued operations 17,361 (2,809 ) 2,308 2,119 3,253 4,059 2,242 2,437 Net income 131,824 61,159 52,818 44,244 200,291 55,734 51,057 59,063 Income per common share - basic (1) 0.87 0.41 0.35 0.29 1.33 0.37 0.34 0.39 Income per common share - diluted (1) 0.87 0.40 0.35 0.29 1.33 0.37 0.34 0.39 (1) The sum of quarterly financial data may vary from the annual data due to rounding.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
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. At December 31, 2017 , the Company's reportable segments were based on the Company's method of internal reporting and were as follows: • Carolinas/Richmond; • Chicago/Minneapolis; • Florida; • Houston; • Lehigh/Central PA; • Philadelphia; • Southeastern PA; and • United Kingdom. Certain other segments are aggregated into an "Other" category which includes the reportable segments: Arizona; Atlanta; Cincinnati/Columbus/Indianapolis; Dallas; DC Metro; New Jersey; and Southern California. 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): Year ended December 31, 2017 2016 2015 Operating revenue Carolinas/Richmond $ 74,158 $ 66,270 $ 71,950 Chicago/Minneapolis 64,706 84,028 85,363 Florida 59,526 99,733 127,184 Houston 59,957 59,582 54,031 Lehigh/Central PA 163,026 141,046 133,473 Philadelphia 45,504 41,838 40,490 Southeastern PA 59,762 91,656 147,712 United Kingdom 13,917 13,376 15,135 Other 130,724 136,521 133,345 Segment-level operating revenue 671,280 734,050 808,683 Reconciliation to total operating revenues Development service fee income (1) 82,673 12,941 — Discontinued operations (34,035 ) (36,010 ) (34,813 ) Other (140 ) (283 ) 90 Total operating revenue $ 719,778 $ 710,698 $ 773,960 Net operating income Carolinas/Richmond $ 53,132 $ 46,170 $ 47,849 Chicago/Minneapolis 39,231 45,258 44,963 Florida 39,850 62,177 77,283 Houston 32,300 32,499 31,159 Lehigh/Central PA 119,304 102,209 94,972 Philadelphia 35,279 30,862 29,679 Southeastern PA 35,641 53,947 80,458 United Kingdom 7,657 6,390 10,486 Other 86,127 89,274 87,925 Segment-level net operating income 448,521 468,786 504,774 Reconciliation to income from continuing operations Interest expense (2) (91,096 ) (115,077 ) (135,779 ) Loss on debt extinguishment (49 ) (27,099 ) — Depreciation/amortization expense (2) (3) (132,613 ) (152,556 ) (166,500 ) Impairment - real estate assets (2) (10,632 ) (3,879 ) (18,244 ) Gain on property dispositions 100,387 219,270 100,314 Equity in earnings of unconsolidated joint ventures 17,155 21,970 3,149 General and administrative expense (2) (3) (45,191 ) (44,341 ) (43,924 ) Expensed pursuit costs (5,006 ) (1,016 ) (605 ) Discontinued operations excluding gain on property dispositions (4,401 ) (11,991 ) (10,565 ) Income taxes (3) (240 ) 47 (2,351 ) Other (5,769 ) 40 5,090 Income from continuing operations $ 271,066 $ 354,154 $ 235,359 (1) Prior to the fourth quarter of 2016, development service fee income had been classified as other income and development service fee expense had been classified as general and administrative expense. See Note 2. (2) Includes activity on discontinued operations. (3) Excludes costs which are included in determining segment-level net operating income. The amount of depreciation and amortization expense related to tenant improvement and lease transaction costs within each reporting segment for the net operating income calculation is as follows (in thousands): Year ended December 31, 2017 2016 2015 Carolinas/Richmond $ 5,061 $ 4,944 $ 5,307 Chicago/Minneapolis 4,306 5,858 6,147 Florida 4,084 6,605 9,407 Houston 5,071 4,713 4,466 Lehigh/Central PA 14,371 12,262 11,641 Philadelphia 2,754 2,706 2,220 Southeastern PA 3,582 6,134 12,346 United Kingdom 339 259 292 Other 9,843 9,792 8,249 Depreciation and amortization of tenant improvement and lease transaction costs $ 49,411 $ 53,273 $ 60,075 The Company's operating revenue by product type and by reportable segment for the years ended December 31, 2017 , 2016 and 2015 is as follows (in thousands): Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Industrial Office Total Industrial Office Total Industrial Office Total Carolinas/Richmond $ 74,158 $ — $ 74,158 $ 66,270 $ — $ 66,270 $ 62,075 $ 9,875 $ 71,950 Chicago/Minneapolis 60,826 3,880 64,706 65,007 19,021 84,028 62,152 23,211 85,363 Florida 56,923 2,603 59,526 66,028 33,705 99,733 67,149 60,035 127,184 Houston 58,606 1,351 59,957 58,370 1,212 59,582 53,802 229 54,031 Lehigh/Central PA 163,026 — 163,026 138,766 2,280 141,046 131,168 2,305 133,473 Philadelphia 11,914 33,590 45,504 12,842 28,996 41,838 11,809 28,681 40,490 Southeastern PA 8,925 50,837 59,762 19,448 72,208 91,656 28,457 119,255 147,712 United Kingdom 10,369 3,548 13,917 10,775 2,601 13,376 12,104 3,031 15,135 Other 102,457 28,267 130,724 91,762 44,759 136,521 86,180 47,165 133,345 $ 547,204 $ 124,076 671,280 $ 529,268 $ 204,782 734,050 $ 514,896 $ 293,787 808,683 Reconciliation to total operating revenue Development service fee income 82,673 12,941 — Discontinued operations (34,035 ) (36,010 ) (34,813 ) Corporate other (140 ) (283 ) 90 Total operating revenue $ 719,778 $ 710,698 $ 773,960 The Company's total assets by reportable segment as of December 31, 2017 and 2016 is as follows (in thousands): As of December 31, 2017 2016 Carolinas/Richmond $ 543,922 $ 503,920 Chicago/Minneapolis 615,186 616,298 Florida 533,861 514,431 Houston 498,584 530,438 Lehigh/Central PA 1,210,746 1,311,815 Philadelphia 665,843 557,510 Southeastern PA 241,128 262,155 United Kingdom 251,824 189,766 Other 1,807,653 1,403,431 Segment-level total assets 6,368,747 5,889,764 Corporate Other 71,010 103,049 Total assets $ 6,439,757 $ 5,992,813 The Company's real estate assets by reportable segment as of December 31, 2017 and 2016 is as follows (in thousands): As of December 31, 2017 2016 Carolinas/Richmond $ 491,634 $ 482,736 Chicago/Minneapolis 557,776 565,062 Florida 483,315 476,046 Houston 456,591 463,739 Lehigh/Central PA 1,118,802 1,234,091 Philadelphia 277,153 332,933 Southeastern PA 19,352 123,093 United Kingdom 191,542 149,082 Other 1,769,705 1,288,208 Total real estate assets $ 5,365,870 $ 5,114,990 The Company incurred the following costs related to its long-lived assets for the years ended December 31, 2017 , 2016 and 2015 (in thousands): Year Ended December 31, 2017 2016 2015 Costs incurred on long-lived assets Carolinas/Richmond $ 31,958 $ 51,647 $ 31,175 Chicago/Minneapolis 14,246 29,317 54,742 Florida 23,832 38,312 43,594 Houston 17,522 25,831 98,559 Lehigh/Central PA 89,304 176,386 165,319 Philadelphia 30,685 57,691 34,122 Southeastern PA 9,737 4,824 5,700 United Kingdom 10,501 11,492 12,960 Other 404,253 107,500 125,412 Total costs incurred on long-lived assets $ 632,038 $ 503,000 $ 571,583

Accounting for the Impairment o

Accounting for the Impairment or Disposal of Long-Lived Assets	12 Months Ended
	Dec. 31, 2017
Accounting for the Impairment or Disposal of Long-Lived Assets [Abstract]
Accounting for the Impairment or Disposal of Long-Lived Assets	ACCOUNTING FOR THE IMPAIRMENT OR DISPOSAL OF LONG-LIVED ASSETS In 2017, the Company initiated a strategic shift whereby it plans to divest of its remaining suburban 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 met the criteria to be classified as held for sale within the new 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 in this report: Held for Sale as of December 31, 2017 Sold during the year ended December 31, 2017 Total Properties included in discontinued operations 25 2 27 Properties included in continuing operations 2 8 10 Properties sold or classified as held for sale 27 10 37 The 25 properties held for sale in discontinued operations as of December 31, 2017 and one property sold during the year ended December 31, 2017 were located in the Company's Southeastern PA reportable segment. The remaining property in discontinued operations that was sold during the year ended December 31, 2017 was located in the Company's Houston reportable segment. A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands): For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Revenues $ 34,035 $ 36,010 $ 34,813 Operating expenses (14,014 ) (12,989 ) (12,309 ) Depreciation and amortization (6,753 ) (8,385 ) (8,711 ) Impairment charges - real estate assets (6,686 ) — (1,029 ) Interest and other income 58 133 23 Interest expense (2,239 ) (2,778 ) (2,222 ) Net income before gain on property dispositions 4,401 11,991 10,565 Gain on property dispositions 14,578 — — Net income 18,979 11,991 10,565 Noncontrolling interest - operating partnership (444 ) (282 ) (246 ) Income available to common shareholders $ 18,535 $ 11,709 $ 10,319 Interest expense has been allocated to discontinued operations. The allocation of interest expense to discontinued operations was based on the ratio of net assets sold and held for sale (without continuing involvement) to the sum of total net assets plus consolidated debt. Capital expenditures on a cash basis for the year ended December 31, 2017, 2016 and 2015 were $8.1 million , $1.5 million and $9.9 million , respectively, related to properties within discontinued operations. In October 2016, the Company completed the sale of a portfolio of 108 properties totaling approximately 7.6 million square feet and 26.7 acres of land for $969 million for a net gain of $179.1 million . As this sale did not represent a strategic shift for the Company, it is not classified as discontinued operations A summary of net income (excluding gain on sale) related to this portfolio is as follows (in thousands): Year Ended December 31, 2016 2015 Net income $ 48,609 $ 58,792 Noncontrolling interest - operating partnership (1,142 ) (1,370 ) Income available to common shareholders $ 47,467 $ 57,422 Assets Held for Sale As of December 31, 2017, 27 operating properties were classified as held for sale, of which 25 operating properties met the criteria to be classified within discontinued operations. Also as of December 31, 2017, two operating properties and 9 acres of land held for development were classified as held for sale and classified within continuing operations. The following table illustrates aggregate balance sheet information for all held-for-sale properties (in thousands): December 31, 2017 December 31, 2016 Included in Continuing Operations Included in Discontinued Operations Total Included in Continuing Operations Included in Discontinued Operations Total Land and land improvements $ 3,476 $ 25,848 $ 29,324 $ — $ 34,406 $ 34,406 Buildings and improvements 80,738 163,195 243,933 — 217,833 217,833 Land held for development 863 — 863 4,548 — 4,548 Accumulated depreciation (11,785 ) (98,346 ) (110,131 ) — (106,933 ) (106,933 ) Deferred financing and leasing costs, net 2,210 3,502 5,712 — 6,355 6,355 Other assets 5,137 7,390 12,527 — 8,679 8,679 Total assets held for sale $ 80,639 $ 101,589 $ 182,228 $ 4,548 $ 160,340 $ 164,888 Total liabilities held for sale $ 1,153 $ 3,398 $ 4,551 $ — $ 8,079 $ 8,079 In January 2018, 14 properties totaling 641,000 square feet which were held for sale and classified in discontinued operation in the Company's Southeastern PA segment as of December 31, 2017 were sold for $76.9 million . Asset Impairment The Company disposes of and anticipates the potential disposition of certain properties prior to the end of their remaining useful lives. During the years ended December 31, 2017 , 2016 and 2015 , the Company recognized impairment losses of $10.6 million , $3.9 million and $18.2 million , respectively. The impairment losses are for operating properties or land parcels and were in the reportable segments and for the amounts as indicated below (in thousands): Year Ended December 31, Reportable Segment 2017 2016 2015 Carolinas/Richmond $ — $ — $ 13,755 Houston 10,632 — — Chicago/Minneapolis — 3,879 — Southeastern PA — — 2,328 Other — — 2,161 Total $ 10,632 $ 3,879 $ 18,244 For the year ended December 31, 2017, $6.7 million in impairments related to properties sold were included in discontinued operations and $3.9 million in impairment - real estate assets, related to land held for development, in the Company's consolidated statements of comprehensive income. For the year ended December 31, 2015, $1.0 million in impairments related to properties sold were included in discontinued operations in the Company's consolidated statements of comprehensive income and $1.0 million in impairment - real estate assets, related to land held for development, in the Company's consolidated statements of comprehensive income. The Company determined these impairments based on third party offer prices and quoted offer prices for comparable transactions which are Level 2 and Level 3 inputs, respectively, according to the fair value hierarchy established in ASC 820. These measurements have occurred throughout the respective periods as circumstances arise, and the resulting estimates of fair value are not necessarily reflective of measurements at the period’s end. The Company has evaluated each of its properties and land held for development and has determined that there were no additional valuation adjustments necessary at December 31, 2017 . The Company applied reasonable estimates and judgments in determining the level of impairments recognized. Should external or internal circumstances change requiring the need to shorten the holding periods or adjust the estimated future cash flows of the Company’s assets, the Company could be required to record impairment charges in the future.

Dervative Instruments

Dervative Instruments	12 Months Ended
	Dec. 31, 2017
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 credit facilities and certain bank mortgage loans bear interest at variable rates. Our long-term debt typically bears interest at fixed rates. The Company's interest rate risk management objectives are to limit generally the impact of interest rate changes on earnings and cash flows and to lower the Company's overall borrowing costs. To achieve these objectives, from time to time, the Company enters into interest rate hedge contracts such as collars, swaps, caps and treasury lock agreements in order to mitigate our interest rate risk with respect to various debt instruments. The Company generally does not hold or issue these derivative contracts for trading or speculative purposes. The interest rate on all of the Company's variable rate debt is generally adjusted at one or three month intervals, subject to settlements under interest rate hedge contracts. Interest rate swaps involve the receipt of variable-rate amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive loss (for the Trust) and general partner's equity and limited partners' equity - common units (for the Operating Partnership) and is subsequently reclassified into interest expense in the period that the hedged forecasted transaction affects earnings. The Company determines the fair value of its interest rate swaps by using the standard methodology of netting discounted future fixed cash payments with the discounted expected variable cash receipts. These variable cash receipts of interest rate swaps are based on expectations of future LIBOR interest rates (forward curves) estimated by observing market LIBOR interest rate curves. This is a Level 2 fair value calculation. Also, credit valuation adjustments are factored into the fair value calculations to account for potential nonperformance risk. These credit valuation adjustments were concluded to be not significant inputs for the fair value calculations for the periods presented. The Company holds an interest in three interest rate swap contracts (“Swaps”) that eliminate the impact of changes in interest rates on the payments required under variable rate mortgages that were also assumed. The Swaps had aggregate notional amounts of $96.2 million and $98.9 million at December 31, 2017 and 2016 , respectively, and expire at various dates between 2018 and 2020 . The Company accounts for the effective portion of changes in the fair value of a derivative in accumulated other comprehensive loss and subsequently reclassifies the effective portion to earnings over the term that the hedged transaction affects earnings. The Company accounts for the ineffective portion of changes in the fair value of a derivative directly in earnings. The following table presents the location in the financial statements of the gains or losses recognized related to the Company’s cash flow hedges for the year ended December 31, 2017 , 2016, and 2015 (in thousands): Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss) $ 176 $ (648 ) $ (1,884 ) Amount of loss related to the effective portion reclassified to interest expense $ (453 ) $ (1,069 ) $ (1,396 ) Amount of gain (loss) related to the ineffective portion recognized in interest expense $ 168 $ (48 ) $ (91 ) The fair value of the interest rate swaps in the amount of $2.2 million and $4.9 million as of December 31, 2017 and 2016 , respectively, is included in other liabilities in the accompanying consolidated balance sheets. The Company estimates that $77,000 will be reclassified from accumulated other comprehensive loss as a decrease to interest expense over the next twelve 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 for approximately $2.3 million .

Supplemental Disclosure to Stat

Supplemental Disclosure to Statements of Cash Flows	12 Months Ended
	Dec. 31, 2017
Supplemental Disclosure to Statements of Cash Flows [Abstract]
Supplemental Disclosure to Statements of Cash Flows	SUPPLEMENTAL DISCLOSURE TO CONSOLIDATED STATEMENT OF CASH FLOWS The following are supplemental disclosures to the statements of cash flows for the years ended December 31, 2017 , 2016 and 2015 (amounts in thousands): 2017 2016 2015 Write-off of fully depreciated/amortized property and deferred costs - properties included in continuing operations $ 16,568 $ 23,331 $ 27,202 Write-off of fully depreciated/amortized property and deferred costs - properties included in discontinued operations 15,368 18,075 15,137 Write-off of depreciated property and deferred costs due to sale/demolition - properties included in continuing operations 15,760 461,480 252,017 Write-off of depreciated property and deferred costs due to sale/demolition - properties included in discontinued operations 17,335 — — Write-off of costs related to early debt extinguishment — 219 — Changes in accrued development capital expenditures - properties included in continuing operations 12,341 (11,274 ) 12,935 Changes in accrued development capital expenditures - properties included in discontinued operations — (94 ) (971 ) Unrealized gain (loss) on cash flow hedge 605 410 (488 ) Capitalized equity-based compensation 1,096 1,221 876 Redemption of noncontrolling interests - common units 152 132 — 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.

Schedule II

Schedule II	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure	Liberty Property Trust and Liberty Property Limited Partnership Schedule II (in thousands) The following table details the activity for the allowance for doubtful accounts. Balance at December 31, 2016 Additions Deductions Balance at December 31, 2017 Allowance for Doubtful Accounts - Straight Line Rent $ 530 $ 1,729 $ (1,710 ) $ 549 Allowance for Doubtful Accounts - Accounts Receivable 6,802 7,248 (7,987 ) 6,063 Total $ 7,332 $ 8,977 $ (9,697 ) $ 6,612 Balance at December 31, 2015 Additions Deductions Balance at December 31, 2016 Allowance for Doubtful Accounts - Straight Line Rent $ 581 $ 824 $ (875 ) $ 530 Allowance for Doubtful Accounts - Accounts Receivable 6,317 4,950 (4,465 ) 6,802 Total $ 6,898 $ 5,774 $ (5,340 ) $ 7,332 Balance at December 31, 2014 Additions Deductions Balance at December 31, 2015 Allowance for Doubtful Accounts - Straight Line Rent $ 910 $ 1,233 $ (1,562 ) $ 581 Allowance for Doubtful Accounts - Accounts Receivable 6,490 4,246 (4,419 ) 6,317 Total $ 7,400 $ 5,479 $ (5,981 ) $ 6,898

Schedule III

Schedule III	12 Months Ended
	Dec. 31, 2017
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real Estate and Accumulated Depreciation	LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 1467 Perryman Road Aberdeen, MD $ — $ 12,052,635 $ — $ 35,353,684 $ 12,334,030 $ 35,072,289 $ 47,406,319 $ 3,266,781 2014 5 - 40 1501 Perryman Road Aberdeen, MD — 5,813,324 18,874,059 6,381,862 5,816,839 25,252,406 31,069,245 7,510,366 2005 5 - 40 869 S Route 53 Addison, IL — 1,194,223 4,201,881 85,733 1,194,223 4,287,615 5,481,838 553,871 2013 5 - 40 901 S Route 53 Addison, IL — 2,055,066 5,984,093 880,440 2,055,066 6,864,533 8,919,599 964,359 2013 5 - 40 8620 Congdon Hill Drive Alburtis, PA — 38,328,000 — 36,639,297 38,328,000 36,639,297 74,967,297 1,625,979 2015 5 - 40 200 Boulder Drive Allentown, PA — 4,722,683 18,922,645 967,059 4,722,683 19,889,704 24,612,387 6,690,719 2004 5 - 40 250 Boulder Drive Allentown, PA — 3,599,936 12,099,145 2,200,244 3,717,733 14,181,592 17,899,325 5,557,571 2004 5 - 40 400 Nestle Way Allentown, PA — 8,065,500 — 29,708,283 8,184,096 29,589,687 37,773,783 15,721,633 1997 5 - 40 650 Boulder Drive Allentown, PA — 5,208,248 — 32,432,054 9,961,788 27,678,514 37,640,302 10,591,886 2002 5 - 40 651 Boulder Drive Allentown, PA — 4,308,646 — 17,846,386 4,308,646 17,846,386 22,155,032 9,669,809 2000 5 - 40 700 Nestle Way Allentown, PA — 3,473,120 — 20,307,750 4,174,970 19,605,900 23,780,870 11,018,939 1998 5 - 40 705 Boulder Drive Allentown, PA — 10,594,027 — 28,815,711 10,596,767 28,812,971 39,409,738 15,981,798 2001 5 - 40 7165 Ambassador Drive Allentown, PA — 792,999 — 4,694,984 804,848 4,683,135 5,487,983 2,146,445 2002 5 - 40 7248 Industrial Boulevard Allentown, PA — 2,670,849 13,307,408 4,629,975 2,670,673 17,937,559 20,608,232 9,398,129 1988 5 - 40 7339 Industrial Boulevard Allentown, PA — 1,187,776 — 7,592,938 1,197,447 7,583,267 8,780,714 4,174,870 1996 5 - 40 7437 Industrial Boulevard Allentown, PA — 717,488 5,022,413 3,450,291 726,651 8,463,540 9,190,191 5,460,929 1976 5 - 40 8014 Industrial Boulevard Allentown, PA — 4,019,258 — 11,192,116 3,645,117 11,566,257 15,211,374 5,409,248 1999 5 - 40 8150 Industrial Boulevard Allentown, PA — 2,564,167 — 9,480,757 2,571,466 9,473,458 12,044,924 3,917,347 2002 5 - 40 8250 Industrial Boulevard Allentown, PA — 1,025,667 — 5,255,168 1,035,854 5,244,981 6,280,835 1,966,477 2002 5 - 40 8400 Industrial Boulevard Allentown, PA — 6,725,948 — 27,404,693 7,521,211 26,609,430 34,130,641 8,076,494 2005 5 - 40 6330 Hedgewood Drive Allentown, PA — 531,268 — 6,075,126 532,047 6,074,347 6,606,394 4,051,848 1988 5 - 40 6350 Hedgewood Drive Allentown, PA — 360,027 — 4,526,417 560,691 4,325,753 4,886,444 2,607,549 1989 5 - 40 6370 Hedgewood Drive Allentown, PA — 540,795 — 4,121,409 541,459 4,120,745 4,662,204 2,579,828 1990 5 - 40 6390 Hedgewood Drive Allentown, PA — 707,203 — 3,372,168 707,867 3,371,504 4,079,371 1,929,807 1990 5 - 40 6520 Stonegate Drive Allentown, PA — 453,315 — 1,571,738 484,361 1,540,692 2,025,053 713,180 1996 5 - 40 6540 Stonegate Drive Allentown, PA — 422,042 — 5,337,554 422,730 5,336,866 5,759,596 3,119,448 1988 5 - 40 6560 Stonegate Drive Allentown, PA — 458,281 — 3,856,829 458,945 3,856,165 4,315,110 2,331,497 1989 5 - 40 6580 Snowdrift Road Allentown, PA — 388,328 — 4,877,166 389,081 4,876,413 5,265,494 3,220,831 1988 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 7620 Cetronia Road Allentown, PA — 1,091,806 3,851,456 446,341 1,093,724 4,295,879 5,389,603 2,379,820 1990 5 - 40 3095 Presidential Drive Atlanta, GA — 200,351 1,729,161 254,912 200,351 1,984,073 2,184,424 342,828 2013 5 - 40 3097 Presidential Drive Atlanta, GA — 188,680 1,721,048 377,679 188,680 2,098,727 2,287,407 252,522 2013 5 - 40 7030 Buford Highway NE Atlanta, GA — * 919,850 4,051,340 938,092 919,850 4,989,432 5,909,282 864,963 2013 5 - 40 Barton 150 Barton Under Needwood, UK — 2,196,955 13,643,981 (2,911,461 ) 1,793,045 11,136,430 12,929,475 1,423,910 2013 5 - 40 1055-1071 Kingsland Drive Batavia, IL — 727,294 2,367,529 686,813 727,294 3,054,342 3,781,636 517,875 2013 5 - 40 4606 Richlynn Drive Belcamp, MD — 299,600 1,818,861 722,992 299,600 2,541,853 2,841,453 1,167,850 1985 5 - 40 11800 Baltimore Avenue Beltsville,MD — 2,769,962 1,829,028 257,575 2,663,725 2,192,841 4,856,566 392,541 2013 5 - 40 11850 Baltimore Avenue Beltsville,MD — 3,595,044 2,415,132 164,695 3,457,162 2,717,709 6,174,871 621,879 2013 5 - 40 11900 Baltimore Avenue Beltsville,MD — 3,492,036 2,024,038 521,421 3,358,104 2,679,391 6,037,495 673,883 2013 5 - 40 12104 Indian Creek Court Beltsville,MD — 2,021,752 2,503,802 301,581 2,021,752 2,805,383 4,827,135 632,738 2013 5 - 40 12200 Indian Creek Court Beltsville,MD — 1,347,882 1,460,291 624,034 1,347,882 2,084,325 3,432,207 374,847 2013 5 - 40 12240 Indian Creek Court Beltsville,MD — 1,479,307 2,159,997 791,326 1,479,307 2,951,324 4,430,631 491,902 2013 5 - 40 1071 Thorndale Avenue Bensenville,IL — 2,173,006 2,280,788 279,995 2,016,715 2,717,074 4,733,789 487,001 2013 5 - 40 1260-1274 Ellis Street Bensenville,IL — * 2,298,560 4,020,382 360,477 2,298,560 4,380,859 6,679,419 753,050 2013 5 - 40 371-377 Meyer Road Bensenville,IL — * 1,903,423 3,563,953 581,985 1,903,423 4,145,938 6,049,361 646,670 2013 5 - 40 850-880 Devon Ave Bensenville,IL — * 2,958,756 7,959,013 780,767 2,958,756 8,739,780 11,698,536 1,397,398 2013 5 - 40 10 Emery Street Bethlehem, PA — 5,591,216 32,941,818 8,086,723 8,947,574 37,672,183 46,619,757 4,444,772 2014 5 - 40 2785 Commerce Center Boulevard Bethlehem, PA — 11,961,623 — 46,710,814 12,009,985 46,662,452 58,672,437 5,682,988 2011 5 - 40 1455 Remington Boulevard Bolingbrook, IL — 2,501,294 10,704,719 2,027 2,501,294 10,706,746 13,208,040 1,443,812 2012 5 - 40 150 E Crossroads Parkway Bolingbrook, IL — * 3,078,949 14,143,377 1,304,570 3,078,949 15,447,947 18,526,896 2,279,751 2013 5 - 40 553 S Joliet Ave Bolingbrook, IL — * 3,764,831 15,109,947 2,608,351 3,764,831 17,718,298 21,483,129 2,927,857 2013 5 - 40 400 Boulder Drive Breinigsville, PA — 2,859,106 — 12,523,348 2,865,575 12,516,879 15,382,454 3,591,183 2003 5 - 40 8201 Industrial Boulevard Breinigsville, PA — 2,089,719 — 9,254,674 2,222,168 9,122,225 11,344,393 2,117,229 2006 5 - 40 8451 Willard Drive Breinigsville, PA — 8,752,708 — 40,892,454 11,511,499 38,133,663 49,645,162 11,459,148 2007 5 - 40 860 Nestle Way Breinigsville, PA — 8,118,881 18,885,486 7,523,072 8,118,881 26,408,558 34,527,439 10,705,203 2004 5 - 40 3525 Gravel Springs Road Buford, GA — 1,391,065 — 5,767,546 1,629,677 5,528,934 7,158,611 81,499 2015 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 3535 Gravel Springs Road Buford, GA — 2,807,020 — 9,348,803 3,077,350 9,078,473 12,155,823 85,572 2015 5 - 40 1485 Dennison Circle Carlisle, PA — 4,249,868 13,886,039 2,345,375 4,095,262 16,386,020 20,481,282 6,860,959 2004 5 - 40 40 Logistics Drive Carlisle, PA — 7,981,850 — 33,019,624 8,081,272 32,920,202 41,001,474 5,205,564 2011 5 - 40 135-195 East Elk Trail Carol Stream, IL — 4,873,094 12,430,320 2,711,700 4,873,094 15,142,020 20,015,114 1,653,950 2013 5 - 40 515 Kehoe Boulevard Carol Stream, IL — 5,523,427 14,581,705 1,018,131 5,523,427 15,599,836 21,123,263 1,794,650 2013 5 - 40 1413 Bradley Lane Carrollton, TX — * 247,477 2,028,322 83,692 247,477 2,112,014 2,359,491 335,971 2013 5 - 40 3200 Belmeade Drive Carrollton, TX — 1,042,453 8,027,974 545,748 1,042,453 8,573,722 9,616,175 1,203,243 2013 5 - 40 16325 S Avalon Blvd Carson, CA — 26,432,369 19,669,675 288,256 26,432,369 19,957,931 46,390,300 90,391 2017 5 - 40 1475 Nitterhouse Dr Chambersburg, PA — 7,081,007 39,002,011 2,094,847 7,081,007 41,096,858 48,177,865 6,065,304 2013 5 - 40 95 Kriner Road Chambersburg, PA — 8,695,501 — 35,060,794 9,407,871 34,348,424 43,756,295 9,231,761 2006 5 - 40 9000 109th Street Champlin, MN — 1,251,043 11,662,995 120,863 1,251,043 11,783,858 13,034,901 2,132,475 2011 5 - 40 11701 Goodrich Drive Charlotte, NC — 2,054,621 6,356,151 630,877 2,054,621 6,987,027 9,041,648 1,347,806 2013 5 - 40 12810 Virkler Drive Charlotte, NC — 475,368 2,367,586 882,005 476,262 3,248,696 3,724,958 563,666 2010 5 - 40 2700 Hutchison McDonald Road Charlotte, NC — 912,500 4,721,259 346,813 912,500 5,068,072 5,980,572 917,487 2011 5 - 40 2701 Hutchison McDonald Road Charlotte, NC — 1,275,000 4,649,750 646,264 1,275,000 5,296,014 6,571,014 985,434 2011 5 - 40 2730 Hutchison McDonald Road Charlotte, NC — 1,878,750 10,129,499 33,298 1,878,750 10,162,797 12,041,547 1,712,638 2011 5 - 40 2801 Hutchison McDonald Road Charlotte, NC — 1,065,000 6,975,250 650,916 1,065,000 7,626,166 8,691,166 1,243,976 2011 5 - 40 3000 Crosspoint Center Lane Charlotte, NC — 1,831,250 10,779,412 1,101,098 1,831,250 11,880,510 13,711,760 2,074,452 2011 5 - 40 3005 Crosspoint Center Lane Charlotte, NC — 1,990,000 6,561,540 1,169,814 1,990,000 7,731,354 9,721,354 1,329,779 2011 5 - 40 4045 Perimeter West Drive Charlotte, NC — 1,418,928 7,511,050 632,664 1,418,928 8,143,714 9,562,642 1,414,308 2011 5 - 40 4047 Perimeter West Drive Charlotte, NC — 1,279,004 — 6,399,609 1,279,004 6,399,609 7,678,613 1,083,916 2011 5 - 40 4525 Statesville Road Charlotte, NC — 841,250 5,279,315 317,199 837,144 5,600,620 6,437,764 958,955 2011 5 - 40 4835 Sirona Drive Charlotte, NC 3,315,149 690,750 5,086,388 133,402 690,750 5,219,790 5,910,540 763,314 2012 5 - 40 4925 Sirona Drive Charlotte, NC 3,339,557 603,003 4,969,011 147,245 603,003 5,116,256 5,719,259 829,242 2012 5 - 40 5032 Sirona Drive Charlotte, NC — 1,416,763 — 9,031,057 1,416,763 9,031,057 10,447,820 469,576 2015 5 - 40 5033 Sirona Drive Charlotte, NC 2,845,006 509,247 4,710,218 183,930 613,962 4,789,433 5,403,395 756,635 2012 5 - 40 5039 Sirona Drive Charlotte, NC — 1,027,500 6,172,807 63,150 1,027,500 6,235,957 7,263,457 512,634 2014 5 - 40 8910 Pioneer Avenue Charlotte, NC — 527,873 4,959,206 360,851 527,873 5,320,057 5,847,930 814,596 2011 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 8916 Pioneer Avenue Charlotte, NC — 557,730 5,785,333 534,333 557,730 6,319,666 6,877,396 1,149,035 2011 5 - 40 8924 Pioneer Avenue Charlotte, NC — 654,713 5,365,823 (57,050 ) 654,713 5,308,773 5,963,486 135,996 2016 5 - 40 2601 Indian River Road Chesapeake, VA — * 1,711,746 10,418,032 494,065 1,711,746 10,912,097 12,623,843 1,619,711 2013 5 - 40 1540 S 54th Avenue Cicero, IL — 3,540,236 20,130,552 930,603 3,540,236 21,061,155 24,601,391 3,002,292 2013 5 - 40 4650 Lake Forest Drive Cincinnati, OH — 1,030,242 4,003,024 365,499 1,030,242 4,368,522 5,398,764 700,153 2013 5 - 40 4750 Lake Forest Drive Cincinnati, OH — 1,138,166 5,914,789 230,664 1,138,166 6,145,453 7,283,619 938,347 2013 5 - 40 9645 Gerwig Lane Columbia, MD — 1,915,960 6,461,228 322,982 1,915,960 6,784,210 8,700,170 1,097,619 2013 5 - 40 2550 John Glenn Avenue Columbus, OH — 540,601 5,129,342 1,072,989 540,601 6,202,331 6,742,932 823,054 2013 5 - 40 3800 Twin Creeks Drive Columbus, OH — 549,393 4,643,302 497,947 549,393 5,141,249 5,690,642 735,305 2013 5 - 40 330 South Royal Lane Coppell, TX — 2,091,426 — 11,407,128 2,091,426 11,407,128 13,498,554 876,255 2014 5 - 40 455 Airline Drive Coppell, TX — * 312,701 2,311,531 489,922 312,701 2,801,453 3,114,154 475,079 2013 5 - 40 2130 Baldwin Avenue Crofton, MD — 3,172,032 7,350,782 419,529 3,172,032 7,770,311 10,942,343 1,188,917 2013 5 - 40 11020 Holly Lane Dayton, MN — 2,536,731 — 12,722,576 2,536,731 12,722,576 15,259,307 475,069 2016 5 - 40 329-333 Herrod Blvd Dayton, NJ — * 4,039,559 20,863,051 2,286,868 4,039,559 23,149,919 27,189,478 3,326,807 2013 5 - 40 1250 Hall Court Deer Park, TX — 829,570 4,778,327 121,291 831,611 4,897,577 5,729,188 1,442,762 2006 5 - 40 333 Howard Avenue Des Plaines, IL — 7,928,724 — 14,264,248 7,928,724 14,264,248 22,192,972 832,239 2016 5 - 40 1680 Executive Drive Duluth, GA — 1,928,412 4,651,819 617,290 1,928,412 5,269,109 7,197,521 1,077,104 2013 5 - 40 1700 Executive Drive Duluth, GA — 1,082,072 2,496,599 573,982 1,082,072 3,070,581 4,152,653 621,884 2013 5 - 40 2670 Breckinridge Blvd Duluth, GA — 1,676,415 4,567,592 927,539 1,676,415 5,495,132 7,171,547 878,785 2013 5 - 40 170 Parkway West Duncan, SC — 598,348 3,643,756 573,870 598,918 4,217,056 4,815,974 1,316,005 2006 5 - 40 190 Parkway West Duncan, SC — 551,663 3,310,993 251,604 552,211 3,562,048 4,114,259 1,067,706 2006 5 - 40 265 Parkway East Duncan, SC — 901,444 5,751,389 193,675 902,374 5,944,134 6,846,508 2,077,614 2006 5 - 40 285 Parkway East Duncan, SC — 975,433 5,851,990 525,729 976,393 6,376,759 7,353,152 1,901,005 2006 5 - 40 1000 Parliament Court Durham, NC — 2,229,000 7,064,506 792,599 2,229,000 7,857,105 10,086,105 791,102 2014 5 - 40 4226 Surles Court Durham, NC — 1,440,000 7,932,265 289,576 1,440,000 8,221,841 9,661,841 954,792 2014 5 - 40 4227 Surles Court Durham, NC — 1,500,000 5,624,030 235,182 1,500,000 5,859,211 7,359,211 534,911 2014 5 - 40 4234 Surles Court Durham, NC — 1,440,000 7,356,161 (78,204 ) 1,440,000 7,277,957 8,717,957 768,425 2014 5 - 40 4300 Emperor Center Durham, NC — 1,576,500 4,240,961 5,859 1,576,500 4,246,820 5,823,320 424,518 2014 5 - 40 1951 TW Alexander Drive Durham, NC — 1,115,595 — 3,618,500 1,324,734 3,409,361 4,734,095 68,813 2015 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 1953 TW Alexander Drive Durham, NC — 2,402,820 — 6,583,503 2,853,273 6,133,050 8,986,323 103,698 2015 5 - 40 1957 TW Alexander Drive Durham, NC — 1,844,943 — 7,946,981 3,091,046 6,700,878 9,791,924 206,273 2015 5 - 40 3169 Dodd Road Eagan, MN — 988,594 6,586,907 394,649 988,594 6,981,556 7,970,150 1,123,900 2012 5 - 40 3711 Kennebec Drive Eagan, MN — 999,702 4,042,589 (2,670 ) 999,702 4,039,919 5,039,621 721,854 2011 5 - 40 917 Lone Oak Road Eagan, MN — * 1,493,115 6,120,455 976,663 1,493,115 7,097,118 8,590,233 1,159,254 2013 5 - 40 10301-10305 West 70th Street Eden Prairie, MN — 120,622 1,085,226 310,448 118,300 1,397,996 1,516,296 699,145 1984 5 - 40 10321 West 70th Street Eden Prairie, MN — 145,198 1,305,700 616,746 142,399 1,925,245 2,067,644 968,278 1984 5 - 40 10333 West 70th Street Eden Prairie, MN — 110,746 995,868 285,918 108,610 1,283,922 1,392,532 656,683 1984 5 - 40 10349-10357 West 70th Street Eden Prairie, MN — 275,903 2,481,666 954,195 270,584 3,441,180 3,711,764 1,842,058 1985 5 - 40 10365-10375 West 70th Street Eden Prairie, MN — 291,077 2,618,194 1,585,889 285,464 4,209,696 4,495,160 1,900,290 1985 5 - 40 10393-10394 West 70th Street Eden Prairie, MN — 269,618 2,423,318 2,527,379 264,419 4,955,896 5,220,315 2,194,769 1985 5 - 40 7075 Flying Cloud Drive Eden Prairie, MN — 10,232,831 10,855,851 4,057,532 9,967,306 15,178,907 25,146,213 3,578,639 2007 5 - 40 7078 Shady Oak Road Eden Prairie, MN — 343,093 3,085,795 1,624,923 336,481 4,717,330 5,053,811 2,636,995 1985 5 - 40 1 Truman Drive South Edison, NJ — 27,862,573 19,426,947 703,083 27,862,573 20,130,030 47,992,603 19,993 2017 5 - 40 2250 Arthur Avenue Elk Grove, IL — 1,403,196 2,386,396 149,289 1,403,196 2,535,685 3,938,881 392,856 2013 5 - 40 6600 Business Parkway Elkridge, MD — 3,680,220 14,671,910 703,042 3,680,220 15,374,952 19,055,172 1,968,894 2013 5 - 40 6675 Business Parkway Elkridge, MD — * 2,421,854 9,730,192 695,870 2,421,854 10,426,062 12,847,916 1,338,178 2013 5 - 40 7351 Coca Cola Drive Elkridge, MD — 1,897,044 — 7,419,134 3,023,417 6,292,761 9,316,178 1,996,209 2006 5 - 40 21705-21707 Mississippi Street Elwood, IL — 10,594,259 30,329,802 1,557,857 10,594,259 31,887,660 42,481,919 5,256,343 2011 5 - 40 27143 Elwood International Port Road Elwood, IL — 6,022,000 5,612,934 587,921 6,022,000 6,200,855 12,222,855 1,087,835 2011 5 - 40 1800 Donaldson Road Erlanger, KY — — 13,211,604 762,210 — 13,973,814 13,973,814 3,972,728 2011 5 - 40 6880 Fairfield Drive Fairfield, OH — 412,136 3,029,177 146,616 412,136 3,175,793 3,587,929 450,893 2013 5 - 40 7000-7018 Fairfield Business Fairfield, OH — 367,925 2,205,817 177,833 386,928 2,364,647 2,751,575 325,215 2013 5 - 40 10721 Jasmine Street Fontana, CA — 11,427,061 23,784,779 3,739,838 11,427,061 27,524,617 38,951,678 1,817,042 2015 5 - 40 2000 Southpointe Dr Forest Park, GA — 756,221 9,115,626 662,099 756,221 9,777,725 10,533,946 1,464,610 2013 5 - 40 1400 NW 65th Place Fort Lauderdale, FL — 545,480 2,540,210 86,121 545,480 2,626,331 3,171,811 341,109 2013 5 - 40 6500 NW 12th Avenue Fort Lauderdale, FL — — 3,064,734 521,736 — 3,586,470 3,586,470 540,454 2013 5 - 40 6501 NW 12th Avenue Fort Lauderdale, FL — 519,984 2,677,465 312,381 519,984 2,989,846 3,509,830 346,270 2013 5 - 40 6600 NW 12th Avenue Fort Lauderdale, FL — — 2,988,181 267,630 — 3,255,811 3,255,811 505,594 2013 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 11222 Melrose Avenue Franklin Park, IL — 2,999,106 4,658,605 104,074 2,999,106 4,762,679 7,761,785 292,028 2016 5 - 40 9601 Cosner Drive Fredericksburg, VA — 475,262 3,917,234 387,315 475,262 4,304,549 4,779,811 2,372,215 1995 5 - 40 5410 - 5430 Northwest 33rd Avenue Ft. Lauderdale, FL — 603,776 4,176,238 1,990,114 625,111 6,145,017 6,770,128 3,281,803 1985 5 - 40 12601 Industry Street Garden Grove, CA — 2,048,143 1,088,697 70,611 2,048,143 1,159,308 3,207,451 276,355 2013 5 - 40 12641 Industry Street Garden Grove, CA — 3,766,822 2,539,214 133,026 3,766,822 2,672,240 6,439,062 408,964 2013 5 - 40 12681-12691 Pala Drive Garden Grove, CA — 5,221,102 3,225,596 83,715 5,220,148 3,310,265 8,530,413 359,715 2014 5 - 40 850 S Jupiter Road Garland, TX — 799,707 6,122,065 506,894 799,707 6,628,959 7,428,666 1,005,200 2013 5 - 40 2510 W Main Street Grand Prairie, TX — * 1,785,741 11,158,818 1,677,983 1,785,741 12,836,801 14,622,542 2,144,063 2013 5 - 40 4251 North Highway 121 Grapevine, TX — * 1,165,780 7,799,270 422,871 1,165,780 8,222,140 9,387,920 1,322,370 2013 5 - 40 1150 Pleasant Ridge Road Greensboro, NC — 1,547,811 — 14,336,534 3,712,683 12,171,662 15,884,345 2,930,846 2006 5 - 40 25 Brookfield Oaks Drive Greenville, SC — 288,823 3,441,512 (60,552 ) 288,823 3,380,960 3,669,783 386,571 2014 5 - 40 45 Brookfield Oaks Drive Greenville, SC — 818,114 — 4,737,211 825,529 4,729,796 5,555,325 1,273,122 2006 5 - 40 2011 Southtech Drive Greenwood, IN — 223,702 3,574,142 348,881 223,702 3,923,023 4,146,725 673,141 2013 5 - 40 2121 Southtech Drive Greenwood, IN — 272,823 3,606,920 425,631 272,823 4,032,552 4,305,375 868,917 2013 5 - 40 800 Commerce Parkway West Dr Greenwood, IN — 1,374,664 29,963,830 2,112,538 1,374,664 32,076,368 33,451,032 4,662,009 2013 5 - 40 110 Caliber Ridge Dr Greer, SC — 555,549 — 6,339,922 1,241,531 5,653,940 6,895,471 472,790 2014 5 - 40 120 Caliber Ridge Dr Greer, SC — 1,243,100 — 6,603,603 1,255,751 6,590,952 7,846,703 516,447 2016 5 - 40 130 Caliber Ridge Dr Greer, SC — 1,171,160 — 6,045,497 1,183,811 6,032,846 7,216,657 326,307 2016 5 - 40 140 Caliber Ridge Drive Greer, SC — 1,243,100 — 6,460,810 1,255,751 6,448,159 7,703,910 594,631 2013 5 - 40 2988 Green Road Greer, SC — 2,271,948 — 6,598,421 2,095,033 6,775,336 8,870,369 56,411 2016 5 - 40 125 Caliber Ridge Drive Greer, SC — 464,237 — 5,840,213 1,311,956 4,992,494 6,304,450 1,143,185 2007 5 - 40 2727 London Groveport Road Groveport, OH — 1,875,607 11,937,935 1,594,848 1,875,607 13,532,783 15,408,390 2,154,022 2013 5 - 40 11835 Newgate Boulevard Hagerstown, MD — 14,121,622 — 23,024,333 14,121,622 23,024,333 37,145,955 2,135,910 2014 5 - 40 11841 Newgate Boulevard Hagerstown, MD — 3,356,207 — 30,679,055 9,741,685 24,293,577 34,035,262 6,578,678 2008 5 - 40 1560 Hunter Road Hanover Park, IL — * 2,639,734 12,310,741 1,072,313 2,639,734 13,383,054 16,022,788 1,884,363 2013 5 - 40 1575 Hunter Road Hanover Park, IL — * 3,293,284 17,235,926 1,174,459 3,293,284 18,410,385 21,703,669 2,655,120 2013 5 - 40 7361 Coca Cola Drive Hanover, MD — 2,245,187 — 9,668,306 3,822,710 8,090,783 11,913,493 1,741,059 2004 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 7460 New Ridge Road Hanover, MD — 3,785,446 — 8,128,924 3,796,023 8,118,347 11,914,370 587,264 2013 5 - 40 7462 New Ridge Road Hanover, MD — 4,059,337 — 7,491,548 4,070,629 7,480,256 11,550,885 511,893 2013 5 - 40 500 McCarthy Drive Harrisburg, PA — 5,194,872 19,991,436 5,020,100 5,687,013 24,519,395 30,206,408 9,042,285 2005 5 - 40 600 Industrial Drive Harrisburg, PA — 7,743,800 — 27,803,943 9,368,557 26,179,186 35,547,743 7,808,361 2005 5 - 40 7195 Grayson Road Harrisburg, PA — 464,534 6,066,272 251,813 464,534 6,318,085 6,782,619 850,896 2013 5 - 40 7253 Grayson Road Harrisburg, PA — 954,130 10,585,367 583,272 954,130 11,168,639 12,122,769 1,466,551 2013 5 - 40 12537 Cerise Avenue Hawthorne, CA — 2,203,194 5,758,809 1,461,971 2,203,194 7,220,780 9,423,974 728,059 2013 5 - 40 1010 Petersburg Road Hebron, KY — 305,471 5,434,505 (819,546 ) 305,471 4,614,959 4,920,430 729,928 2013 5 - 40 785 Lindbergh Court Hebron, KY — 401,410 3,087,899 511,831 401,410 3,599,730 4,001,140 851,287 2013 5 - 40 805 Lindbergh Court Hebron, KY — 292,096 2,502,486 163,832 292,096 2,666,317 2,958,413 460,511 2013 5 - 40 825 Lindbergh Court Hebron, KY — 370,149 3,095,116 435,793 370,149 3,530,910 3,901,059 599,942 2013 5 - 40 845 Lindbergh Court Hebron, KY — 444,318 3,811,889 316,672 444,318 4,128,561 4,572,879 666,370 2013 5 - 40 4198 Eagle Hill Drive High Point, NC — 94,274 — 6,276,671 791,880 5,579,065 6,370,945 1,621,575 2005 5 - 40 4183 Eagle Hill Drive High Point, NC — 122,203 — 3,214,906 526,266 2,810,843 3,337,109 1,311,124 2001 5 - 40 4189 Eagle Hill Drive High Point, NC — 100,106 — 3,584,103 431,106 3,253,103 3,684,209 1,652,112 2001 5 - 40 4193 Eagle Hill Drive High Point, NC — 107,586 — 3,391,727 505,700 2,993,613 3,499,313 968,743 2004 5 - 40 4328, 4336 Federal Drive High Point, NC — 521,122 — 5,624,655 825,092 5,320,685 6,145,777 2,596,135 1995 5 - 40 4344 Federal Drive High Point, NC — 484,001 — 3,152,416 173,623 3,462,794 3,636,417 1,866,989 1996 5 - 40 4380 Federal Drive High Point, NC — 282,996 — 2,209,713 283,368 2,209,341 2,492,709 1,199,039 1997 5 - 40 4388 Federal Drive High Point, NC — 143,661 — 1,214,818 132,655 1,225,824 1,358,479 653,753 1997 5 - 40 4475 Premier Drive High Point, NC — 748,693 — 6,806,962 1,525,421 6,030,234 7,555,655 1,429,865 2006 5 - 40 4485 Premier Drive High Point, NC — 1,827,595 — 6,507,936 1,827,595 6,507,936 8,335,531 174,125 2015 5 - 40 4500 Green Point Drive High Point, NC — 230,622 — 2,757,316 231,692 2,756,246 2,987,938 1,618,070 1989 5 - 40 4501 Green Point Drive High Point, NC — 319,289 — 3,133,118 320,450 3,131,957 3,452,407 1,976,183 1989 5 - 40 4523 Green Point Drive High Point, NC — 234,564 — 3,319,368 235,698 3,318,234 3,553,932 2,236,810 1988 5 - 40 4524 Green Point Drive High Point, NC — 182,810 — 2,838,325 183,888 2,837,247 3,021,135 1,804,718 1989 5 - 40 Unit 5 Logix Road Hinckley, UK — 10,547,677 29,691,911 (7,396,097 ) 8,608,489 24,235,002 32,843,491 3,350,056 2013 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 1000 South Loop West Houston, TX — * 509,351 3,549,504 938,122 509,351 4,487,626 4,996,977 835,033 2013 5 - 40 10241 W Little York Rd Houston, TX — 558,491 5,740,552 139,500 558,491 5,880,052 6,438,543 753,250 2013 5 - 40 10245 W Little York Rd Houston, TX — 426,927 3,460,513 380,296 426,927 3,840,809 4,267,736 795,963 2013 5 - 40 10301 Round Up Lane Houston, TX — 545,501 2,927,700 961,929 545,501 3,889,628 4,435,129 585,432 2010 5 - 40 10305 Round Up Lane Houston, TX — 1,340,609 7,489,720 2,951,546 1,340,609 10,441,265 11,781,874 2,361,657 2010 5 - 40 1050 Greens Parkway Houston, TX — 973,482 — 3,531,792 992,093 3,513,181 4,505,274 252,833 2013 5 - 40 10607 Haddington Drive Houston, TX — * 201,469 1,631,561 132,748 201,469 1,764,310 1,965,779 282,662 2013 5 - 40 10735 West Little York Road Houston, TX — 1,110,988 6,351,946 3,147,449 1,135,483 9,474,900 10,610,383 3,426,368 2000 5 - 40 10739 West Little York Road Houston, TX — 797,931 5,950,894 339,014 799,560 6,288,279 7,087,839 2,419,437 1999 5 - 40 11201 Greens Crossing Boulevard Houston, TX — 1,006,194 5,412,584 2,620,073 1,008,542 8,030,309 9,038,851 2,509,545 2007 5 - 40 11220 Ella Boulevard Houston, TX — 1,505,855 — 7,417,101 1,534,644 7,388,312 8,922,956 529,511 2013 5 - 40 1283 N Post Oak Rd Houston, TX — * 80,730 870,656 145,557 80,730 1,016,213 1,096,943 178,472 2013 5 - 40 1287 N Post Oak Rd Houston, TX — * 146,654 1,620,780 55,679 146,654 1,676,458 1,823,112 280,919 2013 5 - 40 1291 N Post Oak Rd Houston, TX — * 510,102 4,129,042 586,888 510,102 4,715,930 5,226,032 757,450 2013 5 - 40 1416 N Sam Houston Parkway E Houston, TX — * 218,850 1,639,902 558,311 218,850 2,198,212 2,417,062 407,593 2013 5 - 40 1420 N Sam Houston Parkway E Houston, TX — * 211,279 1,554,156 262,982 211,279 1,817,138 2,028,417 253,509 2013 5 - 40 14200 Hollister Road Houston, TX — 1,396,794 — 4,960,376 1,699,632 4,657,538 6,357,170 658,529 2011 5 - 40 1424 N Sam Houston Parkway E Houston, TX — * 283,107 2,077,323 413,088 283,107 2,490,411 2,773,518 377,599 2013 5 - 40 1428 N Sam Houston Parkway E Houston, TX — * 367,446 1,952,453 461,116 367,446 2,413,568 2,781,014 323,367 2013 5 - 40 14300 Hollister Road Houston, TX — * 1,377,193 — 5,680,144 1,405,899 5,651,438 7,057,337 677,019 2014 5 - 40 14400 Hollister Road Houston, TX — * 1,830,419 — 7,240,317 1,861,540 7,209,196 9,070,736 1,763,306 2012 5 - 40 15102 Sommermeyer St Houston, TX — 755,121 3,155,774 247,670 755,121 3,403,444 4,158,565 585,277 2013 5 - 40 15150 Sommermeyer St Houston, TX — 418,580 1,564,587 246,785 418,580 1,811,372 2,229,952 320,777 2013 5 - 40 16330 Central Green Boulevard Houston, TX — 1,540,109 — 8,529,156 1,966,472 8,102,793 10,069,265 824,138 2014 5 - 40 16405 Air Center Boulevard Houston, TX — 438,853 3,030,396 932,746 438,853 3,963,142 4,401,995 1,923,396 1997 5 - 40 16420 West Hardy Road Houston, TX — 529,876 3,267,872 405,454 529,876 3,673,326 4,203,202 603,596 2013 5 - 40 16445 Air Center Boulevard Houston, TX — 363,339 2,509,186 332,364 363,339 2,841,550 3,204,889 1,391,813 1997 5 - 40 LIBERTY PROPERTY TRUST AND LIBERTY PROPERTY LIMITED PARTNERSHIP SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION AS OF DECEMBER 31, 2017 Initial Cost Gross Amount Carried at End of Period Project Location Encumbrances (1) Land Building Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Building and Improvements Total 12/31/2017 Accumulated Depreciation 12/31/2017 Date of Construction or Acquisition Depreciable life (years) OPERATING PROPERTIES 1646 Rankin Road Houston, TX — 329,961 — 5,128,643 592,234 4,866,370 5,458,604 1,625,011 2005 5 - 40 1655 Townhurst Drive Houston, TX — * 197,226 935,036 528,775 197,226 1,463,811 1,661,037 331,956 2013 5 - 40 16580 Air Center Boulevard Houston, TX — 289,000 3,559,857 1,318,020 289,000 4,877,878 5,166,878 2,054,844 1997 5 - 40 16602 Central Green Boulevard Houston, TX — 284,403 — 5,462,115 503,779 5,242,739 5,746,518 1,629,717 2005 5 - 40 16605 Air Center Boulevard Houston, TX — 298,999 — 3,424,045 496,186 3,226,858 3,723,044 1,272,564 2002 5 - 40 1665 Townhurst Drive Houston, TX — * 452,439 2,016,585 532,837 452,439 2,549,421 3,001,860 340,160 2013 5 - 40 16680 Central Green Boulevard Houston, TX — 311,952 — 3,714,436 492,869 3,533,519 4,026,388 863,726 2001 5 - 40 16685 Air Center Boulevard Houston, TX — 414,691 — 2,455,433 414,691 2,455,433 2,870,124 820,383 2004 5 - 40 1755 Trans Central Drive Houston, TX — 293,534 3,036,269 1,254,342 306,147 4,277,998 4,584,145 1,661,466 1999 5 - 40 4301 S Pinemont Dr Houston, TX — * 226,973 1,174,979 142,669 226,973 1,317,648 1,544,621 279,123 2013 5 - 40 4401 S Pinemont Dr Houston, TX — * 244,240 1,412,622 164,426 244,240 1,577,048 1,821,288 322,106 2013 5 - 40 4501 S Pinemont Dr Houston, TX — * 252,907 1,504,053 106,793 252,907 1,610,846 1,863,753 223,579 2013 5 - 40 5200 N. Sam Houston Parkway Houston, TX — 1,519,458 7,135,548 3,704,347 1,520,074 10,839,279 12,359,353 3,591,298 2007 5 - 40 5250 N. Sam Houston Parkway Houston, TX — 2,173,287 8,868,256 2,845,225 2,173,942 11,712,826 13,886,768 2,982,334 2007 5 - 40 5500 N. Sam Houston Parkway West Houston, TX — 1,243,541 — 6,356,567 1,513,152 6,086,956 7,600,108 1,284,483 2011 5 - 40 8017 Pinemont Drive Houston, TX — 900,953 5,323,727 442,546 900,953 5,766,273 6,667,226 756,953 2013 5 - 40 8272 El Rio Street Houston, TX — * 530,494 4,108,626 302,930 530,494 4,411,556 4,942,050 669,352 2013 5 - 40 8282 El Rio Street Houston, TX — * 450,422 3,304,942 1,085,091 450,422 4,390,033 4,840,455 770,811 2013 5 - 40 8301 Fallbrook Drive Houston, TX — 4,515,862 — 26,996,308 7,083,514 24,428,656 31,512,170 6,261,457 2006 5 - 40 8303 Fallbrook Drive Houston, TX — 4,613,370 — 16,413,097 4,858,863 16,167,604 21,026,467 998,943 2013 5 - 40 850 Greens Parkway Houston, TX — 2,893,405 11,593,197 2,915,414 2,899,861 14,502,154 17,402,015 3,779,158 2007 5 - 40 860 Greens Parkway Houston, TX — 1,399,365 6,344,650 1,637,084 1,374,012 8,007,087 9,381,099 2,105,831 2007 5 - 40 8801-19 & 8821-49 Fallbrook Drive Houston, TX — 2,290,001 15,297,141 4,097,089 2,290,002 19,394,229 21,684,231 6,703,077 2000 5 - 40 8802-8824 Fallbrook Drive Houston, TX — 2,774,995 6,364,767 2,050,563 2,775,021 8,415,303 11,190,324 2,583,641 2004 5 - 40 8825-8839 N Sam Houston Pkwy Houston, TX — 638,453 3,258,815 740,807 638,477 3,999,597 4,638,074 1,428,818 2004 5 - 40 8850-8872 Fallbrook Drive Houston, TX — 504,317 2,878,351 1,952,678 504,341 4,831,005 5,335,346 1,740,453 2004 5 - 40 16200 Central Green Blvd Houston, TX — 1,748,348 — 9,342,218 2,120,319 8,970,247 11,090,566 1,448,476 2012 5 - 40 LIBERTY PROPERT

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share, Basic and Diluted [Line Items]
Organization	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 December 31, 2017 . The Company owns and operates industrial properties nationally and owns and operates office properties in a focused group of office markets. Additionally, the Company owns certain assets in the United Kingdom. Unless otherwise indicated, the notes to the Consolidated Financial Statements apply to both the Trust and the Operating Partnership. The terms the "Company,” “we,” “our” and “us” means the Trust and Operating Partnership collectively.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles ("US GAAP") requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements of the Company include the Trust, the Operating Partnership, wholly owned subsidiaries and those subsidiaries in which the Company owns a majority voting interest with the ability to control operations of the subsidiaries and where no approval, veto or other important rights have been granted to the noncontrolling shareholders. The Company consolidates joint ventures that are considered to be variable interest entities (“VIEs”) where we are the primary beneficiary. The Company (i) evaluates the sufficiency of the total equity investment at risk, (ii) reviews the voting rights and decision-making authority of the equity investment holders as a group and whether there are any guaranteed returns, protection against losses, or capping of residual returns within the group and (iii) establishes whether activities within the venture are on behalf of an investor with disproportionately few voting rights in making this VIE determination. To the extent that the Company (i) is the sole entity that has the power to direct the activities of the VIE and (ii) has the obligation or rights to absorb the VIE's losses or receive its benefits, then the Company would be the primary beneficiary and would consolidate the VIE. All significant intercompany transactions and accounts have been eliminated.
Reclassifications	Reclassifications Certain amounts from prior years have been reclassified to conform to current-year presentation including reclassifying the accompanying consolidated balance sheets for assets held for sale and the consolidated statements of comprehensive income for discontinued operations. In 2017, the Company began to separately classify expensed pursuit costs in the Consolidated Statements of Comprehensive Income. These costs, which were reclassed retrospectively for all periods, were formerly classified as general and administrative expense.
Concentration of Credit Risk	Concentration of Credit Risk As of December 31, 2017, wholly owned properties were leased to 1,091 customers. The geographic locations that comprise greater than 10% of our rental and other revenues were Lehigh Valley/Central PA and Philadelphia. Our customers engage in a wide variety of businesses. No single customer generated more than 4.6% of our consolidated operating rental revenues during 2017.
Real Estate and Depreciation	Real Estate and Depreciation The properties are recorded at cost and are depreciated using the straight line method over their estimated useful lives. The estimated useful lives are as follows: Building and improvements 40 years (blended) Capital improvements 15 - 20 years Equipment 5 - 10 years Tenant improvements Term of the related lease The Company capitalizes costs associated with development and redevelopment activities, capital improvements, tenant improvements and leasing activities, including compensation costs. Expenditures directly related to the improvement of real estate, including interest and other costs capitalized on development and redevelopment projects and land being readied for development, are included in net real estate and are stated at cost. The Company considers a development property substantially complete upon the completion of tenant build-out, but no later than one year after the completion of major construction activity. These capitalized costs include pre-construction costs essential to the development of the property, construction costs, interest costs, real estate taxes, development related compensation and other costs incurred during the period of development. The determination to capitalize rather than expense costs requires the Company to evaluate the status of the development activity. The total of capitalized compensation costs directly related to development, redevelopment, capital improvements, and tenant improvements for the years ended December 31, 2017 , 2016 and 2015 was $5.5 million , $7.2 million and $5.5 million , respectively. Construction related payables at December 31, 2017 and 2016 were $49.3 million and $37.1 million , respectively. The Company allocates the purchase price of real estate acquired to land, building and improvements and intangibles based on the relative fair value of each component. Lease values for acquired properties are determined based on the present value (using a discount rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management's estimate of fair market lease rates for each corresponding in-place lease ("Market Value Intangible"). Origination values are also assigned to in-place leases, and, where appropriate, value is assigned to customer relationships ("Origination Value Intangible"). Acquisition-related costs for vacant properties are capitalized and included in net real estate at cost. Beginning on October 1, 2016, acquisition-related costs for properties with in-place leases deemed to be asset acquisitions are also capitalized and included in net real estate at cost. Expenditures for maintenance and repairs are charged to operations as incurred. The Company depreciates the amounts allocated to building and improvements over 40 years and amortizes the amounts allocated to intangibles relating to in-place leases, which are included in deferred financing and leasing costs and other liabilities in the accompanying consolidated balance sheets, over the remaining term of the related leases. Market Value Intangible amortization is recorded as rental revenue. Origination Value Intangible amortization is recorded as depreciation and amortization. This calculation includes both the remaining noncancelable period and any bargain renewal option periods. Once a property is designated as held for sale, no further depreciation expense is recorded. The Company evaluates its real estate investments upon occurrence of a significant adverse change in its operations to assess whether any impairment indicators are present that affect the recovery of the recorded value. If indicators of impairment are identified, the Company estimates the future undiscounted cash flows from the use and eventual disposition of the property and compares this amount to the carrying value of the property. If any real estate investment is considered impaired, a loss is recognized to reduce the carrying value of the property to its estimated fair value.
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures The Company accounts for its investments in unconsolidated joint ventures using the equity method of accounting as the Company exercises significant influence, but does not control these entities. Under the equity method of accounting, the net equity investment of the Company is reflected in the accompanying consolidated balance sheets and the Company's share of net income from the joint ventures is included in the accompanying consolidated statements of comprehensive income. On a periodic basis, management assesses whether there are any indicators that the value of the Company's investments in unconsolidated joint ventures may be other-than-temporarily-impaired. An investment is impaired only if management's estimate of the value of the investment is less than the carrying value of the investment, and such decline in value is deemed to be other-than-temporary. To the extent impairment has occurred, the loss is measured as the excess of the carrying amount of the investment over the estimated fair value of the investment. The estimated fair value of the investments is determined using a discounted cash flow model which is a Level 3 valuation under ASC 820, " Fair Value Measurement ." The Company considers a number of assumptions that are subject to economic and market uncertainties including, among others, demand for space, competition for tenants, changes in market rental rates, operating costs, capitalization rates, holding periods and discount rates.
Cash and Cash Equivalents	Cash and Cash Equivalents Highly liquid investments with a maturity of three months or less when purchased are classified as cash equivalents.
Restricted Cash	Restricted Cash 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 residential land in Kent County, United Kingdom.
Accounts Receivable/Deferred Rent Receivable	Accounts Receivable/Deferred Rent Receivable The Company's accounts receivable are comprised of rents and charges for property operating costs due from tenants. The Company's deferred rent receivable represents the cumulative difference between rent revenue recognized on a straight line basis and contractual payments due under the terms of tenant leases. The Company periodically performs a detailed review of amounts due from tenants to determine if accounts receivable and deferred rent receivable balances are collectible. Based on this review, accounts receivable and deferred rent receivable are reduced by an allowance for doubtful accounts. The Company considers tenant credit quality and payment history and general economic conditions in determining the allowance for doubtful accounts. If the accounts receivable balance or the deferred rent receivable balance is subsequently deemed uncollectible, the receivable and allowance for doubtful account balance are written off.
Revenue Recognition	Revenue Recognition The Company earns rental income under operating leases with tenants. Rental income is recognized on a straight line basis over the applicable non-cancelable lease term. Operating expense reimbursements consisting of amounts due from tenants for real estate taxes, utilities and other recoverable costs are recognized as revenue in the period in which the corresponding expenses are incurred. The Company considers any renewal options in determining the lease term. To the extent a lease includes a tenant option to renew or extend the duration of the lease at a fixed or determinable rental rate, the Company evaluates whether or not that option represents a bargain renewal option by analyzing if there is reasonable assurance at lease inception that the tenant will exercise the option because the rental rate is sufficiently lower than the expected rental rate for equivalent property under similar terms and conditions at the exercise date. Termination fees (included in rental revenue) are fees that the Company has agreed to accept in consideration for permitting certain tenants to terminate their lease prior to the contractual expiration date. The Company recognizes termination fees during the period that landlord services are rendered in accordance with Securities and Exchange Commission Staff Accounting Bulletin 104, " Revenue Recognition ," after the following conditions are met: a. the termination agreement is executed, b. the termination fee is determinable, and c. collectability of the termination fee is assured. In the fourth quarter of 2016, the Company entered into an agreement relating to the fee development of an office building at its Camden Waterfront project in Camden, NJ. Project revenues and related costs and expenses are presented on a gross basis as "Development service fee income" and "Development service fee expense" in the Consolidated Statements of Comprehensive Income. Additionally, at the same time, the Company began classifying development fees and expenses relating to its fee development arrangements for certain unconsolidated joint venture projects in a manner consistent with the Camden project described above. Previously, development service fee income relating to its unconsolidated joint ventures had been classified as other income and development service fee expense had been classified as general and administrative expense in amounts as follows: Nine months ended Year ended September 30, 2016 December 31, 2015 (unaudited) Other income $ 3,789 $ 6,159 General and administrative expense $ 3,210 $ 3,730 Revenue and expense associated with service fee development is accounted for under the percentage of completion method. Revenues are recognized on the percentage of completion method based on applicable costs incurred with respect to each development agreement. The Company uses the relative sales value method to allocate costs and recognize profits from service fee development. Under the relative sales value method, estimates of aggregate project revenues and aggregate project costs are used to determine the allocation of project cost of sales and the resulting profit in each accounting period. In subsequent periods, cost of sale allocations and the resulting profits are adjusted to reflect changes in the actual and estimated costs and revenues of each project. Provisions for estimated losses on uncompleted contracts are recognized immediately in the period in which such losses are determined.
Deferred Financing and Leasing Costs	Deferred Financing and Leasing Costs Costs incurred in connection with the financing of the credit facilities or leasing are capitalized and amortized on a straight line basis over the term of the related loan or lease. Costs incurred in connection with the financing of mortgage loans or unsecured notes are reported as a deduction from the face amount of that liability and amortized on a straight line basis over the term of the related loan. Deferred financing cost amortization is reported as interest expense. Certain employees of the Company are compensated for leasing services related to the Company's properties. The compensation directly related to these leasing services is capitalized and amortized as a deferred leasing cost over the term of the related lease.
Fair Value of Financial Instruments	Fair Value of Financial Instruments ASC 820, Fair Value Measurements and Disclosures , gives 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, 2017 and December 31, 2016 . 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 also 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 20 - Derivative Instruments. The Company used a discounted cash flow model to determine the estimated fair value of its debt as of December 31, 2017 and December 31, 2016 . 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.
Income Taxes	Income Taxes The Company has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the "Code"). As a result, the Company generally is not subject to federal income taxation at the corporate level to the extent it distributes annually at least 100% of its REIT taxable income, as defined in the Code, to its shareholders and satisfies certain other organizational and operational requirements. The Company has met these requirements and, accordingly, no provision has been made for federal income taxes in the accompanying consolidated financial statements. If the Company fails to qualify as a REIT in any taxable year, the Company will be subject to federal income tax on its taxable income at regular corporate rates (including any alternative minimum tax) and may not be able to qualify as a REIT for the four subsequent taxable years. Even as a REIT, the Company may still be subject to certain state and local income and property taxes, and to federal income and excise taxes on undistributed taxable income. The Company has considered the provisions of the Tax Cuts and Jobs Act (the "TCJA"), which was signed into law on December 22, 2017 and which generally takes effect for taxable years beginning on or after January 1, 2018, and does not expect the TCJA to have a material impact on its overall business operations or ability to continue to qualify as a REIT. Several of the Company's subsidiaries are taxable REIT subsidiaries (each a "TRS") and are subject to federal and state income taxes separate from the Company. In general, a TRS may perform additional services for tenants and generally may engage in real estate or non-real estate businesses that are not permitted REIT activities. The Company itself is also subject to tax in certain states and the United Kingdom. Accordingly, the Company recognizes federal, state and foreign income taxes in accordance with US GAAP, as applicable. In addition, the TCJA implemented a one-time deemed repatriation tax on offshore corporate profits, including any such profits which the Company may have accumulated over the years in its offshore TRSs, at the reduced rates of 15.5% on cash assets and 8% on noncash assets. The Company has reviewed its accumulated offshore earnings through December 31, 2017 and does not expect this provision of the TCJA will have a material impact on the Company’s overall financial condition or results of operation. There are no uncertain tax positions or possibly significant unrecognized tax benefits that are reasonably expected to occur within the next 12 months. The Company's policy is to recognize interest accrued related to unrecognized benefits in interest expense and penalties in other expense. There were no interest or penalties deducted in any of the years ended December 31, 2017 , 2016 and 2015 and no interest and penalties accrued at December 31, 2017 or December 31, 2016 which related to any uncertain tax positions or significant unrecognized tax benefits. Certain of the Company's TRSs had net operating loss ("NOL") carryforwards available of approximately $40.6 million as of December 31, 2017 . The TCJA reduced the corporate federal tax rate in the U.S. to 21.0% effective for tax years beginning after December 31, 2017. As such, deferred tax assets and liabilities, where applicable, were remeasured using the lower corporate federal tax rate at December 31, 2017. These NOL carryforwards begin to expire in 2018 . After taking into consideration future taxable income and consistent with prior periods, the Company has determined that a valuation allowance for the full carrying value of NOL carryforwards is appropriate. The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction, certain state and local jurisdictions, the United Kingdom and (in prior years) Luxembourg. With few exceptions, the Company and its subsidiaries are no longer subject to examination by taxing authorities in these jurisdictions for years prior to 2011.
Share-based Compensation	Share-Based Compensation Share-based compensation cost is measured at the grant date, based on the fair value of the award, and is recognized as expense over the employees' requisite service period.
Selling, General and Administrative Expenses, Policy [Policy Text Block]	Expensed Pursuit Costs The Company capitalizes pre-development costs incurred in pursuit of new development opportunities for which the Company currently believes future development is probable. Future development is dependent upon various factors, including zoning and regulatory approval, rental market conditions and construction costs. Initial pre-development costs incurred for pursuits for which future development is not yet considered probable are expensed as incurred. In addition, if the status of a future development by the Company is no longer probable, any capitalized pre-development costs are written off with a charge to expense.
Derivative Financial Instruments	Derivative Financial Instruments We borrow funds at a combination of fixed and variable rates. Borrowings under our revolving credit facility and certain bank mortgage loans bear interest at variable rates. Our long-term debt typically bears interest at fixed rates. Our interest rate risk management objectives are to limit generally the impact of interest rate changes on earnings and cash flows and to lower our overall borrowing costs. To achieve these objectives, from time to time, we enter into interest rate hedge contracts such as collars, swaps, caps and treasury lock agreements in order to mitigate our interest rate risk with respect to various debt instruments. We generally do not hold or issue these derivative contracts for trading or speculative purposes. The interest rate on all of our variable rate debt is generally adjusted at one or three month intervals, subject to settlements under interest rate hedge contracts. Interest rate swaps involve the receipt of variable-rate amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive loss (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.
Foreign Currency	Foreign Currency The functional currency of the Company's United Kingdom operations is pounds sterling. The Company translates the financial statements for the United Kingdom operations into US dollars. For the Trust, gains and losses resulting from this translation are included in accumulated other comprehensive loss as a separate component of shareholders' equity and a proportionate amount of gain or loss is allocated to noncontrolling interest - operating partnership - common units. For the Operating Partnership, gains and losses resulting from this translation are included in general partner's equity and limited partners' equity - common units. Upon sale or upon complete or substantially complete liquidation of the Company's foreign investment, the gain or loss on the sale will include the cumulative translation adjustments that have been previously recorded in accumulated other comprehensive loss and noncontrolling interest - operating partnership - common units (for the Trust) and in general partner's equity and limited partners' equity - common units (for the Operating Partnership).
Comprehensive Income	Comprehensive Income Comprehensive income, as reflected on the consolidated statements of comprehensive income, is defined as all changes in equity during each period except for those resulting from investments by or distributions to shareholders. Accumulated other comprehensive loss, as reflected on the Company's consolidated balance sheets and consolidated statements of equity, reflects the effective portion of the cumulative changes in the fair value of derivatives in qualifying cash flow hedge relationships as well as gains and losses resulting from foreign currency translation.
Sales of Real Estate	Sales of Real Estate The Company accounts for the sale of real estate assets and any related gain recognition in accordance with the accounting guidance applicable to sales of real estate, which establishes standards for recognition of profit on all real estate sales transactions, other than retail land sales. The Company recognizes the sale, and associated gain or loss from the disposition, provided that the earnings process is complete and the Company is not obligated to perform significant activities after the sale.
Earnings Per Share/Unit	Earnings Per Share of the REIT Basic earnings per share is calculated by dividing the income available to common shareholders for the period by the weighted average number of common shares outstanding during the period using the two class method. Diluted earnings per share is calculated by dividing the net income available to common shareholders for the period by the weighted average number of common and dilutive securities outstanding during the period.
Recently Issued Accounting Standards	Recently Issued Accounting Standards 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 the following standards related to ASU 2014-09: ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations; ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ; ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ; and ASU 2017-13, Revenue from Contracts with Customers (Topic 606): Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments (collectively, the “New Revenue Standards”). The New Revenue Standards clarify the required factors that an entity must consider when recognizing revenue and require additional disclosures concerning contracts with customers, judgments concerning revenue recognition, and assets recognized for the costs to obtain or fulfill a contract. The Company concluded that there are no revenue streams from its lease agreements that are covered by the New Revenue Standards with the exception of non-lease components as further discussed below. Once the new guidance setting forth principles for the recognition, measurement, presentation and disclosure of leases goes into effect on January 1, 2019, the Company believes that the New Revenue Standards will apply to components of revenue due under leases that are deemed to be non-lease components (such as common area maintenance and provision of utilities), which could affect the recognition pattern for such revenue. The Company has completed its evaluation of the New Revenue Standards' impact on its remaining revenue streams. The Company adopted this standard effective January 1, 2018 using the modified retrospective approach, which requires applying the new standard to all existing contracts not yet completed as of the effective date and recording a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The New Revenue Standards will not have a material impact on the measurement and recognition of gains and losses on the sale of properties. The New Revenue Standards will not have a material impact on the amount and timing of recognizing its development service fee income, which is currently accounted for under the percentage of completion method based on applicable costs incurred and estimated to be incurred. The Company has completed its evaluation of the standard's impact on its revenue streams. The Company does not believe the adoption of the New Revenue Standards will have a material impact on the consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"). ASU 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU 2016-02 is effective for the Company beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. The standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. For leases in which the Company is the lessor, the standard requires that the lease and non-lease components of the lease agreement should be separated. Revenue related to the lease component of the contract will be recognized on a straight-line basis, while revenue related to the non-lease component will be recognized under the provisions of the New Revenue Standards. For lease agreements longer than one year in which the Company is the lessee, the Company will measure the present value of the future lease payments and recognize a right-of-use asset and corresponding lease liability on its balance sheet. In addition, the new standard states that only direct leasing costs may be capitalized. The Company is evaluating the impact ASU 2016-02 will have on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships ("ASU 2016-05"). ASU 2016-05 states that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under FASB Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted ASU 2016-05 beginning January 1, 2017 on a prospective basis. The adoption of ASU 2016-05 did not have a material impact on its financial position and results of operations. In March 2016, the FASB issued ASU 2016-09. ASU 2016-09 is designed to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The Company adopted ASU 2016-09 beginning January 1, 2017. Certain amendments in the standard were applied retrospectively and certain amendments were applied prospectively. The adoption of ASU 2016-09 did not have a material impact on its financial position and results of operations. The impact of the implementation of ASU 2016-09 is shown in the table below. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 is designed to clarify how entities should classify cash receipts and cash payments in the statement of cash flows. ASU 2016-15 is effective for the Company beginning January 1, 2018. Early adoption of ASU 2016-15 is permitted. The standard requires retrospective application unless it is impracticable to do so. The Company is evaluating the impact ASU 2016-15 will have on its statement of cash flows. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230) - Restricted Cash (“ASU 2016-18”) , which requires that restricted cash and cash equivalents be included with cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the consolidated statements of cash flows. The new standard is effective for public entities for fiscal years beginning after December 15, 2017 and for interim periods therein, with early adoption permitted. The Company adopted ASU 2016-18 as of December 31, 2017. The impact of the implementation of ASU 2016-18 and ASU 2016-09 was as follows: Year Ended December 31, 2017 2016 2015 Net cash provided by operating activities (prior to adoption of ASU 2016-09 and ASU 2016-18) $ 331,337 $ 333,021 $ 385,366 Impact of including restricted cash with cash and cash equivalents 187 2,669 (10,478 ) Impact of including shares related to tax withholdings in financing activities 5,107 5,372 4,233 Net cash provided by operating activities (after adoption of ASU 2016-09 and ASU 2016-18) $ 336,631 $ 341,062 $ 379,121 Net cash (used in) provided by investing activities (prior to adoption of ASU 2016-18) $ (465,652 ) $ 613,402 $ (89,660 ) Impact of including restricted cash with cash and cash equivalents — 1,525 — Net cash (used in) provided by investing activities (after adoption of ASU 2016-18) $ (465,652 ) $ 614,927 $ (89,660 ) Net cash provided by (used in) financing activities (prior to adoption of ASU 2016-09) $ 101,338 $ (934,135 ) $ (327,627 ) Impact of including shares related to tax withholdings in financing activities (5,107 ) (5,372 ) (4,233 ) Net cash provided by (used in) financing activities (prior to adoption of ASU 2016-09) $ 96,231 $ (939,507 ) $ (331,860 ) In February 2017, the FASB issued ASU 2017-05, Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets ("ASU 2017-05"). ASU 2017-05 is designed to provide guidance on how to recognize gain and losses on sales, including partial sale, of nonfinancial assets to noncustomers. The Company adopted ASU 2017-05 effective January 1, 2018 on a modified retrospective method and the adoption will not have a material effect on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Scope of Modification Accounting ("ASU 2017-09"). ASU 2017-09 clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. ASU 2017-09 is effective for the Company beginning January 1, 2018. Early adoption is permitted. The new guidance will be applied prospectively to awards modified on or after the adoption date. The Company does not believe the adoption of the ASU 2017-09 will have a material impact on the consolidated financial statements. 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. ASU 2017-12 is effective for the Company beginning January 1, 2019. Early adoption is permitted using a modified retrospective transition method. This adoption method will require the Company to recognize the cumulative effect of initially applying ASU 2017-12 as an adjustment to accumulated other comprehensive income with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year that an entity adopts the update. The Company is evaluating the impact ASU 2017-12 will have on the Company's financial position and results of operations.
Interest Expense Allocated to Discontinued Operations	Interest expense has been allocated to discontinued operations. The allocation of interest expense to discontinued operations was based on the ratio of net assets sold and held for sale (without continuing involvement) to the sum of total net assets plus consolidated debt.
Accounting for the Impairment or Disposal of Long-Lived Assets	The Company determined these impairments based on third party offer prices and quoted offer prices for comparable transactions which are Level 2 and Level 3 inputs, respectively, according to the fair value hierarchy established in ASC 820. These measurements have occurred throughout the respective periods as circumstances arise, and the resulting estimates of fair value are not necessarily reflective of measurements at the period’s end. The Company has evaluated each of its properties and land held for development and has determined that there were no additional valuation adjustments necessary at December 31, 2017 . The Company applied reasonable estimates and judgments in determining the level of impairments recognized. Should external or internal circumstances change requiring the need to shorten the holding periods or adjust the estimated future cash flows of the Company’s assets, the Company could be required to record impairment charges in the future.
Liberty Property Limited Partnership [Member]
Earnings Per Share, Basic and Diluted [Line Items]
Earnings Per Share/Unit	Earnings Per Unit of the Operating Partnership Basic earnings per unit is calculated by dividing the income available to common unitholders for the period by the weighted average number of common units outstanding during the period using the two class method. Diluted earnings per unit is calculated by dividing the income available to common unitholders for the period by the weighted average number of common and dilutive securities outstanding during the period.

Accounting for the Impairment32

Accounting for the Impairment or Disposal of Long-Lived Assets Discontinued Operations (Policies)	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations, Policy [Policy Text Block]	The Company determined that the strategic shift would have a major effect on its operations and financial results. As such, properties sold or met the criteria to be classified as held for sale within the new 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.

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	The impact of the implementation of ASU 2016-18 and ASU 2016-09 was as follows: Year Ended December 31, 2017 2016 2015 Net cash provided by operating activities (prior to adoption of ASU 2016-09 and ASU 2016-18) $ 331,337 $ 333,021 $ 385,366 Impact of including restricted cash with cash and cash equivalents 187 2,669 (10,478 ) Impact of including shares related to tax withholdings in financing activities 5,107 5,372 4,233 Net cash provided by operating activities (after adoption of ASU 2016-09 and ASU 2016-18) $ 336,631 $ 341,062 $ 379,121 Net cash (used in) provided by investing activities (prior to adoption of ASU 2016-18) $ (465,652 ) $ 613,402 $ (89,660 ) Impact of including restricted cash with cash and cash equivalents — 1,525 — Net cash (used in) provided by investing activities (after adoption of ASU 2016-18) $ (465,652 ) $ 614,927 $ (89,660 ) Net cash provided by (used in) financing activities (prior to adoption of ASU 2016-09) $ 101,338 $ (934,135 ) $ (327,627 ) Impact of including shares related to tax withholdings in financing activities (5,107 ) (5,372 ) (4,233 ) Net cash provided by (used in) financing activities (prior to adoption of ASU 2016-09) $ 96,231 $ (939,507 ) $ (331,860 )
Property Deprecation Schedule	The properties are recorded at cost and are depreciated using the straight line method over their estimated useful lives. The estimated useful lives are as follows: Building and improvements 40 years (blended) Capital improvements 15 - 20 years Equipment 5 - 10 years Tenant improvements Term of the related lease
Fair Value of Mortgage Loans and Unsecured Notes	The following summarizes the fair value of the Company's mortgage loans and unsecured notes at December 31, 2016 and December 31, 2017 (in thousands): Mortgage Loans Unsecured Notes Carrying Value Fair Value Carrying Value Fair Value As of December 31, 2016 $ 276,650 $ 286,684 $ 2,280,286 $ 2,340,762 As of December 31, 2017 $ 267,093 $ 267,298 $ 2,283,513 $ 2,359,998
Schedule of Adjustment to Previously Reported Consolidated Financial Statements	Previously, development service fee income relating to its unconsolidated joint ventures had been classified as other income and development service fee expense had been classified as general and administrative expense in amounts as follows: Nine months ended Year ended September 30, 2016 December 31, 2015 (unaudited) Other income $ 3,789 $ 6,159 General and administrative expense $ 3,210 $ 3,730

Income per Common Share of th34

Income per Common Share of the Trust (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): 2017 2016 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 $ 263,805 146,742 $ 1.79 $ 345,108 146,204 $ 2.36 Dilutive shares for long-term compensation plans — 799 — 685 Income from continuing operations net of noncontrolling interest - diluted $ 263,805 147,541 $ 1.78 $ 345,108 146,889 $ 2.35 Discontinued operations net of noncontrolling interest - basic $ 18,535 146,742 $ 0.13 $ 11,709 146,204 $ 0.08 Dilutive shares for long-term compensation plans — 799 — 685 Discontinued operations net of noncontrolling interest - diluted $ 18,535 147,541 $ 0.13 $ 11,709 146,889 $ 0.08 Net income available to common shareholders - basic $ 282,340 146,742 $ 1.92 $ 356,817 146,204 $ 2.44 Dilutive shares for long-term compensation plans — 799 — 685 Net income available to common shareholders - diluted $ 282,340 147,541 $ 1.91 $ 356,817 146,889 $ 2.43 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 229,164 148,243 $ 1.55 Dilutive shares for long-term compensation plans — 600 Income from continuing operations net of noncontrolling interest - diluted $ 229,164 148,843 $ 1.54 Discontinued operations net of noncontrolling interest - basic $ 10,319 148,243 $ 0.07 Dilutive shares for long-term compensation plans — 600 Discontinued operations net of noncontrolling interest - diluted $ 10,319 148,843 $ 0.07 Net income available to common shareholders - basic $ 239,483 148,243 $ 1.62 Dilutive shares for long-term compensation plans — 600 Net income available to common shareholders - diluted $ 239,483 148,843 $ 1.61

Income per Common Unit of the35

Income per Common Unit of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Unit, Basic and Diluted [Line Items]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts): 2017 2016 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 $ 263,805 146,742 $ 1.79 $ 345,108 146,204 $ 2.36 Dilutive shares for long-term compensation plans — 799 — 685 Income from continuing operations net of noncontrolling interest - diluted $ 263,805 147,541 $ 1.78 $ 345,108 146,889 $ 2.35 Discontinued operations net of noncontrolling interest - basic $ 18,535 146,742 $ 0.13 $ 11,709 146,204 $ 0.08 Dilutive shares for long-term compensation plans — 799 — 685 Discontinued operations net of noncontrolling interest - diluted $ 18,535 147,541 $ 0.13 $ 11,709 146,889 $ 0.08 Net income available to common shareholders - basic $ 282,340 146,742 $ 1.92 $ 356,817 146,204 $ 2.44 Dilutive shares for long-term compensation plans — 799 — 685 Net income available to common shareholders - diluted $ 282,340 147,541 $ 1.91 $ 356,817 146,889 $ 2.43 2015 Income (Numerator) Weighted Average Shares (Denominator) Per Share Income from continuing operations net of noncontrolling interest - basic $ 229,164 148,243 $ 1.55 Dilutive shares for long-term compensation plans — 600 Income from continuing operations net of noncontrolling interest - diluted $ 229,164 148,843 $ 1.54 Discontinued operations net of noncontrolling interest - basic $ 10,319 148,243 $ 0.07 Dilutive shares for long-term compensation plans — 600 Discontinued operations net of noncontrolling interest - diluted $ 10,319 148,843 $ 0.07 Net income available to common shareholders - basic $ 239,483 148,243 $ 1.62 Dilutive shares for long-term compensation plans — 600 Net income available to common shareholders - diluted $ 239,483 148,843 $ 1.61
Liberty Property Limited Partnership [Member]
Earnings Per Unit, Basic and Diluted [Line Items]
Schedule of Earnings Per Share, Basic and Diluted	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): 2017 2016 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 $ 270,585 $ 353,896 Less: Preferred unit distributions (472 ) (472 ) Income from continuing operations available to common unitholders - basic $ 270,113 150,270 $ 1.79 $ 353,424 149,740 $ 2.36 Dilutive units for long-term compensation plans — 799 — 685 Income from continuing operations available to common unitholders - diluted $ 270,113 151,069 $ 1.78 $ 353,424 150,425 $ 2.35 Income from discontinued operations - basic $ 18,979 150,270 $ 0.13 $ 11,991 149,740 $ 0.08 Dilutive units for long-term compensation plans 799 685 Income from discontinued operations - diluted $ 18,979 151,069 $ 0.13 $ 11,991 150,425 $ 0.08 Income available to common unitholders - basic $ 289,092 150,270 $ 1.92 $ 365,415 149,740 $ 2.44 Dilutive units for long-term compensation plans 799 685 Income available to common unitholders - diluted $ 289,092 151,069 $ 1.91 $ 365,415 150,425 $ 2.43 2015 Income (Numerator) Weighted Average Units (Denominator) Per Unit Income from continuing operations net of noncontrolling interest - consolidated joint ventures $ 235,110 Less: Preferred unit distributions (472 ) Income from continuing operations available to common unitholders - basic $ 234,638 151,783 $ 1.55 Dilutive units for long-term compensation plans — 600 Income from continuing operations available to common unitholders - diluted $ 234,638 152,383 $ 1.54 Income from discontinued operations - basic $ 10,565 151,783 $ 0.07 Dilutive units for long-term compensation plans — 600 Income from discontinued operations - diluted $ 10,565 152,383 $ 0.07 Income available to common unitholders - basic $ 245,203 151,783 $ 1.62 Dilutive units for long-term compensation plans — 600 Income available to common unitholders - diluted $ 245,203 152,383 $ 1.61

Accumulated Other Comprehensi36

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The following table sets forth the components of Accumulated Other Comprehensive Loss (in thousands): December 31, 2017 2016 Foreign Currency Translation: Beginning balance $ (56,767 ) $ (22,023 ) Translation adjustment 18,066 (34,744 ) Ending balance (38,701 ) (56,767 ) Derivative Instruments: Beginning balance (455 ) (865 ) Unrealized loss 152 (659 ) Reclassification adjustment (1) 453 1,069 Ending balance 150 (455 ) Total accumulated other comprehensive loss (38,551 ) (57,222 ) Less: portion included in noncontrolling interest – operating partnership 754 1,191 Total accumulated other comprehensive loss included in shareholders' equity $ (37,797 ) $ (56,031 ) (1) Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate (Tables)

Real Estate (Tables)	12 Months Ended
	Dec. 31, 2017
Real Estate [Abstract]
Schedule of Carrying Value of Properties	The carrying value of these operating properties by type as of December 31, 2017 and 2016 is as follows (in thousands): Land Building and Land and Accumulated Improvements Improvements Total Depreciation 2017 Industrial properties $ 1,001,454 $ 3,873,830 $ 4,875,284 $ 814,301 Office properties 152,226 569,753 721,979 126,312 2017 Total $ 1,153,680 $ 4,443,583 $ 5,597,263 $ 940,613 2016 Industrial properties $ 914,428 $ 3,725,331 $ 4,639,759 $ 719,658 Office properties 145,637 572,681 718,318 127,448 2016 Total $ 1,060,065 $ 4,298,012 $ 5,358,077 $ 847,106
Disposal Group, Including Discontinued Operations	Information on the operating properties the Company sold during the years ended December 31, 2017 , 2016 and 2015 is as follows: 2017 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Chicago/Minneapolis 3 — 136,110 $ 8,917 Florida — 16 — 13,256 Houston 1 42 206,808 36,145 Lehigh/Central PA 2 44 1,683,876 249,045 Southeastern PA 4 3 313,410 56,156 Other — 8 — 3,739 Total 10 113 2,340,204 $ 367,258 2016 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Chicago/Minneapolis 24 5 2,037,275 $ 199,825 Florida 51 12 3,509,641 505,828 Lehigh/Central PA 1 — 120,777 11,200 Philadelphia — 1 — 2,640 Southeastern PA 31 — 2,165,002 266,821 Other 18 18 1,631,295 224,241 Total 125 36 9,463,990 $ 1,210,555 2015 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Carolinas/Richmond 22 3 1,319,299 $ 110,054 Chicago/Minneapolis 2 — 222,642 25,700 Florida 4 — 874,125 55,425 Southeastern PA 46 20 2,724,489 316,583 Other 7 — 569,618 37,371 Total 81 23 5,710,173 $ 545,133 A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands): For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Revenues $ 34,035 $ 36,010 $ 34,813 Operating expenses (14,014 ) (12,989 ) (12,309 ) Depreciation and amortization (6,753 ) (8,385 ) (8,711 ) Impairment charges - real estate assets (6,686 ) — (1,029 ) Interest and other income 58 133 23 Interest expense (2,239 ) (2,778 ) (2,222 ) Net income before gain on property dispositions 4,401 11,991 10,565 Gain on property dispositions 14,578 — — Net income 18,979 11,991 10,565 Noncontrolling interest - operating partnership (444 ) (282 ) (246 ) Income available to common shareholders $ 18,535 $ 11,709 $ 10,319 The following table illustrates aggregate balance sheet information for all held-for-sale properties (in thousands): December 31, 2017 December 31, 2016 Included in Continuing Operations Included in Discontinued Operations Total Included in Continuing Operations Included in Discontinued Operations Total Land and land improvements $ 3,476 $ 25,848 $ 29,324 $ — $ 34,406 $ 34,406 Buildings and improvements 80,738 163,195 243,933 — 217,833 217,833 Land held for development 863 — 863 4,548 — 4,548 Accumulated depreciation (11,785 ) (98,346 ) (110,131 ) — (106,933 ) (106,933 ) Deferred financing and leasing costs, net 2,210 3,502 5,712 — 6,355 6,355 Other assets 5,137 7,390 12,527 — 8,679 8,679 Total assets held for sale $ 80,639 $ 101,589 $ 182,228 $ 4,548 $ 160,340 $ 164,888 Total liabilities held for sale $ 1,153 $ 3,398 $ 4,551 $ — $ 8,079 $ 8,079 The following table illustrates the number of sold or held-for-sale properties included in, or excluded from, discontinued operations in this report: Held for Sale as of December 31, 2017 Sold during the year ended December 31, 2017 Total Properties included in discontinued operations 25 2 27 Properties included in continuing operations 2 8 10 Properties sold or classified as held for sale 27 10 37
Schedule of Operating Properties and Land Parcels Acquired	Information on the operating properties and land parcels the Company acquired during the years ended December 31, 2017 , 2016 and 2015 is as follows: 2017 Acquisitions Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Purchase Price (in thousands) Carolinas/Richmond — 11 — $ 1,242 Lehigh/Central PA — 95 — 17,798 United Kingdom — 35 — 12,550 Other 8 113 1,861,879 264,808 Total 8 254 1,861,879 $ 296,398 2016 Acquisitions Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Purchase Price (in thousands) Carolinas/Richmond — 13 — $ 2,251 Chicago/Minneapolis 1 6 73,160 11,064 Lehigh/Central PA — 76 — 15,395 Philadelphia — 6 — 13,943 Southeastern PA — 8 — 3,344 Other — 108 — 14,895 Total 1 217 73,160 $ 60,892 2015 Acquisitions Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Purchase Price (in thousands) Carolinas/Richmond — 94 — $ 1,727 Chicago/Minneapolis 1 188 197,956 24,541 Houston 3 139 921,196 86,497 Lehigh/Central PA — 281 — 62,402 Other 1 56 410,059 45,248 Total 5 758 1,529,211 $ 220,415 Subsequent to December 31, 2017, the Company closed on the acquisition of a 400,000 square foot property in its Southern California segment for a Total Investment of $92.7 million .

Investments in Unconsolidated38

Investments in Unconsolidated Joint Ventures (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Condensed Balance Sheet of Equity Method Investments	The condensed balance sheets as of December 31, 2017 and 2016 and condensed statements of operations for the years ended December 31, 2017 , 2016 and 2015 for Liberty Venture I LP, Kings Hill Unit Trust, Liberty Illinois, LP, Liberty Washington LP, Liberty/Comcast, Liberty Property 18th & Arch, and the other unconsolidated joint ventures are as follows (in thousands): Condensed Balance Sheets: December 31, 2017 Liberty Kings Hill Liberty Liberty Liberty/ Liberty Property Venture I, LP Unit Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other Total Real estate assets $ 229,600 $ 152,998 $ 252,593 $ 274,847 $ 496,210 $ 551,874 $ 98,589 $ 2,056,711 Accumulated depreciation (48,629 ) (30,028 ) (57,444 ) (49,106 ) (138,943 ) (4,070 ) (10,995 ) (339,215 ) Real estate assets, net 180,971 122,970 195,149 225,741 357,267 547,804 87,594 1,717,496 Development in progress 18,337 — — — — 289,767 — 308,104 Land held for development — — 33,500 — — — 41,075 74,575 Other assets 20,722 10,957 16,337 18,566 49,755 98,191 24,263 238,791 Total assets $ 220,030 $ 133,927 $ 244,986 $ 244,307 $ 407,022 $ 935,762 $ 152,932 $ 2,338,966 Debt $ 166,295 $ 92,131 $ 138,869 $ 102,624 $ 305,223 $ — $ 63,999 $ 869,141 Other liabilities 4,117 28,056 7,548 4,954 9,488 102,982 8,420 165,565 Equity 49,618 13,740 98,569 136,729 92,311 832,780 80,513 1,304,260 Total liabilities and equity $ 220,030 $ 133,927 $ 244,986 $ 244,307 $ 407,022 $ 935,762 $ 152,932 $ 2,338,966 Company's net investment in unconsolidated joint ventures (1) $ 10,425 $ 6,100 $ 14,980 $ 34,107 $ 17,307 $ 177,843 $ 27,694 $ 288,456 December 31, 2016 Liberty Kings Hill Liberty Liberty Liberty/ Liberty Property Venture I, LP Unit Trust Illinois, LP Washington, LP Comcast 18th and Arch (2) Other Total Real estate assets $ 226,313 $ 137,960 $ 251,765 $ 289,627 $ 495,842 $ — $ 71,722 $ 1,473,229 Accumulated depreciation (42,779 ) (26,872 ) (51,901 ) (44,235 ) (125,014 ) — (9,702 ) (300,503 ) Real estate assets, net 183,534 111,088 199,864 245,392 370,828 — 62,020 1,172,726 Development in progress 6,886 — — — — 671,032 — 677,918 Land held for development — — 31,567 — — — 42,259 73,826 Other assets 23,494 9,603 19,036 18,749 48,074 52,053 29,654 200,663 Total assets $ 213,914 $ 120,691 $ 250,467 $ 264,141 $ 418,902 $ 723,085 $ 133,933 $ 2,125,133 Debt $ 154,386 $ 83,846 $ 137,294 $ 103,667 $ 309,475 $ — $ 57,660 $ 846,328 Other liabilities 6,673 24,513 8,433 4,385 9,964 95,574 17,155 166,697 Equity 52,855 12,332 104,740 156,089 99,463 627,511 59,118 1,112,108 Total liabilities and equity $ 213,914 $ 120,691 $ 250,467 $ 264,141 $ 418,902 $ 723,085 $ 133,933 $ 2,125,133 Company's net investment in unconsolidated joint ventures (1) $ 11,175 $ 5,349 $ 15,339 $ 38,863 $ 18,688 $ 132,952 $ 22,712 $ 245,078
Schedule of Condensed Statements of Operations of Equity Method Investments	Condensed Statements of Operations: Year Ended December 31, 2017 Liberty Kings Hill Unit Liberty Liberty Liberty/ Liberty Property Venture I, LP Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other (3) Total Total revenue $ 31,079 $ 12,976 $ 23,711 $ 25,439 $ 65,372 $ 16,544 $ 11,118 $ 186,239 Operating expense 8,101 4,756 7,989 9,147 26,474 3,417 3,365 63,249 Net operating income 22,978 8,220 15,722 16,292 38,898 13,127 7,753 122,990 Interest (5,801 ) (2,329 ) (5,882 ) (4,065 ) (19,411 ) — (2,807 ) (40,295 ) Depreciation and amortization (7,598 ) (3,238 ) (6,918 ) (5,926 ) (14,485 ) (4,077 ) (2,124 ) (44,366 ) Other income (expense) (100 ) (4 ) (71 ) (65 ) (325 ) (547 ) 15,549 14,437 Gain (loss) on sale/impairment — — — (15,910 ) — 30 — (15,880 ) Net income (loss) $ 9,479 $ 2,649 $ 2,851 $ (9,674 ) $ 4,677 $ 8,533 $ 18,371 $ 36,886 Company's equity in earnings (loss) of unconsolidated joint ventures $ 2,914 $ 660 $ 2,118 $ (1,941 ) $ 1,659 $ 1,782 $ 9,963 $ 17,155 Year Ended December 31, 2016 Liberty Kings Hill Unit Liberty Liberty Liberty/ Liberty Property Venture I, LP Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other (3) Total Total revenue $ 25,149 $ 11,926 $ 26,599 $ 39,727 $ 65,587 $ — $ 9,888 $ 178,876 Operating expense 6,835 4,854 9,961 15,935 26,761 280 2,801 67,427 Net operating income 18,314 7,072 16,638 23,792 38,826 (280 ) 7,087 111,449 Interest (4,182 ) (2,554 ) (7,243 ) (10,866 ) (19,737 ) — (2,462 ) (47,044 ) Depreciation and amortization (6,375 ) (3,557 ) (7,589 ) (10,750 ) (14,513 ) — (1,925 ) (44,709 ) Other income (expense) 50 (77 ) 64 257 (213 ) 1,270 7,123 8,474 Gain (loss) on sale/impairment — — 4,068 40,943 — — (11 ) 45,000 Net income $ 7,807 $ 884 $ 5,938 $ 43,376 $ 4,363 $ 990 $ 9,812 $ 73,170 Company's equity in earnings (loss) of unconsolidated joint ventures $ 2,332 $ 275 $ 2,065 $ 10,857 $ 1,594 $ 213 $ 4,634 $ 21,970 Year Ended December 31, 2015 Liberty Kings Hill Unit Liberty Liberty Liberty/ Liberty Property Venture I, LP Trust Illinois, LP Washington, LP Comcast 18th & Arch (2) Other (3) Total Total revenue $ 23,708 $ 12,602 $ 26,085 $ 71,101 $ 68,444 $ — $ 9,387 $ 211,327 Operating expense 7,977 5,261 9,303 27,384 29,692 221 2,727 82,565 Net operating income 15,731 7,341 16,782 43,717 38,752 (221 ) 6,660 128,762 Interest (5,415 ) (6,116 ) (8,441 ) (17,353 ) (19,936 ) — (2,248 ) (59,509 ) Depreciation and amortization (6,399 ) (3,954 ) (7,406 ) (20,725 ) (14,442 ) — (1,840 ) (54,766 ) Other income (expense) 68 45,604 29 531 (227 ) 30 9,925 55,960 Income (loss) from discontinued operations 760 — — (56,792 ) — — — (56,032 ) Net income (loss) $ 4,745 $ 42,875 $ 964 $ (50,622 ) $ 4,147 $ (191 ) $ 12,497 $ 14,415 Company's equity in earnings (loss) of unconsolidated joint ventures $ 1,540 $ (425 ) $ 807 $ (7,314 ) $ 2,053 $ (29 ) $ 6,517 $ 3,149 (1) Differences between the Company's net investment in unconsolidated joint ventures and its underlying equity in the net assets of the venture are primarily a result of impairments related to the Company's investment in unconsolidated joint ventures, the deferral of gains associated with the sales of properties to joint ventures in which the Company retains an ownership interest and loans made to the joint ventures by the Company. These adjustments have resulted in an aggregate difference reducing the Company's investments in unconsolidated joint ventures by $3.0 million and $1.4 million as of December 31, 2017 and 2016 , respectively. Differences between historical cost basis and the basis reflected at the joint venture level (other than loans) are typically depreciated over the life of the related asset. (2) Represents the combined results of two joint ventures related to the property at 18th and Arch Streets, Philadelphia. (3) Other income/(expense) for this group of joint ventures reflects gains related to the sales of land leasehold interests totaling $16.0 million , $7.1 million and $9.9 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Deferred Financing and Leasin39

Deferred Financing and Leasing Costs (Tables)	12 Months Ended
	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Schedule of Deferred Financing and Leasing Costs	Deferred financing and leasing costs were comprised of the following as of December 31, 2017 and 2016 (in thousands): December 31, 2017 2016 Deferred financing costs $ 17,044 $ 11,917 Deferred leasing costs 198,767 179,161 Market value intangible 18,802 19,451 Origination value intangible 90,116 83,485 324,729 294,014 Accumulated amortization: Deferred financing costs 11,002 10,152 Deferred leasing costs 80,434 70,842 Market value intangible 14,324 12,625 Origination value intangible 59,719 53,357 165,479 146,976 Deferred financing and leasing costs, net $ 159,250 $ 147,038
Leases, Acquired-in-Place, Market Adjustment [Member]
Finite-Lived Intangible Assets [Line Items]
Schedule of Future Amortization Expense	The aggregate amortization of net market value intangible assets and liabilities is a decrease (increase) in rental revenue over the next five years and thereafter as follows (in thousands): 2018 $ 242 2019 (265 ) 2020 (858 ) 2021 (891 ) 2022 (762 ) Thereafter (2,637 ) Total $ (5,171 )
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Schedule of Future Amortization Expense	The aggregate amortization expense for origination value intangible asset for the next five years and thereafter is as follows (in thousands): 2018 $ 9,748 2019 6,437 2020 3,664 2021 2,839 2022 2,158 Thereafter 5,551 Total $ 30,397

Indebtedness (Tables)

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Debt	The scheduled principal amortization and maturities of the Company's mortgage loans, unsecured notes outstanding and the Credit Facilities (as defined below) and the related weighted average interest rates at December 31, 2017 are as follows (in thousands, except percentages): Weighted Mortgages Average Principal Principal Unsecured Credit Interest Amortization Maturities Notes Facilities Total Rate 2018 $ 6,565 $ 26,995 $ — $ — $ 33,560 3.20 % 2019 6,504 50,043 — — 56,547 3.95 % 2020 3,539 67,361 350,000 — 420,900 4.66 % 2021 2,504 65,009 — 358,939 426,452 2.62 % 2022 2,172 — 400,000 — 402,172 4.13 % 2023 2,281 — 300,000 — 302,281 3.39 % 2024 2,395 — 450,000 — 452,395 4.40 % 2025 2,503 — 400,000 — 402,503 3.76 % 2026 2,494 1,946 400,000 — 404,440 3.26 % 2027 and thereafter 19,800 — — — 19,800 4.84 % Subtotal $ 50,757 $ 211,354 $ 2,300,000 $ 358,939 $ 2,921,050 3.77 % Reconciling items (1) 4,982 — (16,487 ) — (11,505 ) Total for consolidated balance sheet $ 55,739 $ 211,354 $ 2,283,513 $ 358,939 $ 2,909,545 (1) Includes deferred financing costs, premium/discount and market adjustments.

Leasing Activity (Tables)

Leasing Activity (Tables)	12 Months Ended
	Dec. 31, 2017
Operating Leases, Future Minimum Payments Receivable [Abstract]
Schedule of Future Minimum Rental Payments	Future minimum rental payments due from tenants under noncancelable operating leases as of December 31, 2017 are as follows (in thousands): 2018 $ 493,131 2019 462,698 2020 394,462 2021 334,969 2022 273,715 Thereafter 1,102,030 Total $ 3,061,005

Noncontrolling Interest - Ope42

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Tables)	12 Months Ended
	Dec. 31, 2017
Noncontrolling Interest - Operating Partnership / LImited Partners' Equity - Preferred Units [Abstract]
Schedule of Preferred Units	As of December 31, 2017 , the Company had outstanding the following cumulative preferred units of the Operating Partnership: ISSUE AMOUNT UNITS LIQUIDATION PREFERENCE DIVIDEND RATE (in 000’s) Series I-2 $ 7,537 301 $25 6.25 %

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Shareholders' Equity [Abstract]
Schedule of Taxability of Common Shares	The following unaudited table summarizes the taxability of common share distributions (taxability for 2017 is estimated): 2017 2016 2015 Ordinary dividend $ 1.5369 $ 1.0319 $ 1.4348 Qualified dividend 0.0150 0.0013 — Capital gain - 20% 0.0482 — 0.1112 IRC Sec 1250 unrecaptured gain - 25% 0.0749 0.6176 0.3372 Return of capital — 0.2492 0.0168 Total $ 1.6750 $ 1.9000 $ 1.9000

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation [Abstract]
Schedule of Valuation Assumptions	The following weighted-average assumptions were utilized in calculating the fair value of options granted during the periods indicated: Year Ended December 31, 2015 Risk-free interest rate 1.8% Dividend yield 5.2% Historical volatility factor 0.24 Weighted-average expected life 7 years
Schedule of Stock Options Activity	A summary of the Company's share option activity and related information for the year ended December 31, 2017 follows: Options (000s) Weighted Average Exercise Price Outstanding January 1, 2017 1,927 $ 36.02 Exercised (193 ) 34.72 Forfeited (153 ) 48.58 Outstanding December 31, 2017 1,581 $ 34.97 Exercisable at December 31, 2017 1,417 $ 34.95
Schedule of Key Assumptions Used in the Monte Carlo Simulation	The key assumptions used in the Monte Carlo simulations are as follows: Year Ended December 31, 2017 2016 2015 Risk-free interest rate 1.43% 1.01% 0.99% Volatility 20% 19% 17%
Schedule of Nonvested Share Activity	The Company's restricted LTI share activity for the year ended December 31, 2017 is as follows: Shares (000s) Weighted Avg. Grant Date Fair value Nonvested at January 1, 2017 812 $ 34.71 Granted 310 39.93 Vested (330 ) 35.57 Forfeited (17 ) 35.07 Nonvested at December 31, 2017 775 $ 36.43

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Rental Payments	Future minimum rental payments under the terms of all non-cancelable operating ground leases under which the Company is the lessee, as of December 31, 2017 , were as follows (in thousands): Year Amount 2018 $ 1,771 2019 1,766 2020 1,766 2021 1,766 2022 1,720 2023 though 2067 33,160 Total $ 41,949

Quarterly Results of Operatio46

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	A summary of quarterly results of operations for the years ended December 31, 2017 and 2016 follows (in thousands, except for per share data): QUARTER ENDED DEC. 31, SEPT. 30, JUNE 30, MAR. 31, DEC. 31, SEPT. 30, JUNE 30, MAR. 31, 2017 2017 2017 2017 2016 2016 2016 2016 Operating revenue $ 192,803 $ 184,511 $ 174,888 $ 167,576 $ 169,733 $ 181,967 $ 178,033 $ 180,965 Income from continuing operations 114,463 63,968 50,510 42,125 197,038 51,675 48,815 56,626 Discontinued operations 17,361 (2,809 ) 2,308 2,119 3,253 4,059 2,242 2,437 Net income 131,824 61,159 52,818 44,244 200,291 55,734 51,057 59,063 Income per common share - basic (1) 0.87 0.41 0.35 0.29 1.33 0.37 0.34 0.39 Income per common share - diluted (1) 0.87 0.40 0.35 0.29 1.33 0.37 0.34 0.39 (1) The sum of quarterly financial data may vary from the annual data due to rounding.

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The operating information by reportable segment is as follows (in thousands): Year ended December 31, 2017 2016 2015 Operating revenue Carolinas/Richmond $ 74,158 $ 66,270 $ 71,950 Chicago/Minneapolis 64,706 84,028 85,363 Florida 59,526 99,733 127,184 Houston 59,957 59,582 54,031 Lehigh/Central PA 163,026 141,046 133,473 Philadelphia 45,504 41,838 40,490 Southeastern PA 59,762 91,656 147,712 United Kingdom 13,917 13,376 15,135 Other 130,724 136,521 133,345 Segment-level operating revenue 671,280 734,050 808,683 Reconciliation to total operating revenues Development service fee income (1) 82,673 12,941 — Discontinued operations (34,035 ) (36,010 ) (34,813 ) Other (140 ) (283 ) 90 Total operating revenue $ 719,778 $ 710,698 $ 773,960 Net operating income Carolinas/Richmond $ 53,132 $ 46,170 $ 47,849 Chicago/Minneapolis 39,231 45,258 44,963 Florida 39,850 62,177 77,283 Houston 32,300 32,499 31,159 Lehigh/Central PA 119,304 102,209 94,972 Philadelphia 35,279 30,862 29,679 Southeastern PA 35,641 53,947 80,458 United Kingdom 7,657 6,390 10,486 Other 86,127 89,274 87,925 Segment-level net operating income 448,521 468,786 504,774 Reconciliation to income from continuing operations Interest expense (2) (91,096 ) (115,077 ) (135,779 ) Loss on debt extinguishment (49 ) (27,099 ) — Depreciation/amortization expense (2) (3) (132,613 ) (152,556 ) (166,500 ) Impairment - real estate assets (2) (10,632 ) (3,879 ) (18,244 ) Gain on property dispositions 100,387 219,270 100,314 Equity in earnings of unconsolidated joint ventures 17,155 21,970 3,149 General and administrative expense (2) (3) (45,191 ) (44,341 ) (43,924 ) Expensed pursuit costs (5,006 ) (1,016 ) (605 ) Discontinued operations excluding gain on property dispositions (4,401 ) (11,991 ) (10,565 ) Income taxes (3) (240 ) 47 (2,351 ) Other (5,769 ) 40 5,090 Income from continuing operations $ 271,066 $ 354,154 $ 235,359 (1) Prior to the fourth quarter of 2016, development service fee income had been classified as other income and development service fee expense had been classified as general and administrative expense. See Note 2. (2) Includes activity on discontinued operations. (3) Excludes costs which are included in determining segment-level net operating income.
Schedule of Depreciation and Amortization	The amount of depreciation and amortization expense related to tenant improvement and lease transaction costs within each reporting segment for the net operating income calculation is as follows (in thousands): Year ended December 31, 2017 2016 2015 Carolinas/Richmond $ 5,061 $ 4,944 $ 5,307 Chicago/Minneapolis 4,306 5,858 6,147 Florida 4,084 6,605 9,407 Houston 5,071 4,713 4,466 Lehigh/Central PA 14,371 12,262 11,641 Philadelphia 2,754 2,706 2,220 Southeastern PA 3,582 6,134 12,346 United Kingdom 339 259 292 Other 9,843 9,792 8,249 Depreciation and amortization of tenant improvement and lease transaction costs $ 49,411 $ 53,273 $ 60,075
Revenue from External Customers by Products and Services	The Company's operating revenue by product type and by reportable segment for the years ended December 31, 2017 , 2016 and 2015 is as follows (in thousands): Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Industrial Office Total Industrial Office Total Industrial Office Total Carolinas/Richmond $ 74,158 $ — $ 74,158 $ 66,270 $ — $ 66,270 $ 62,075 $ 9,875 $ 71,950 Chicago/Minneapolis 60,826 3,880 64,706 65,007 19,021 84,028 62,152 23,211 85,363 Florida 56,923 2,603 59,526 66,028 33,705 99,733 67,149 60,035 127,184 Houston 58,606 1,351 59,957 58,370 1,212 59,582 53,802 229 54,031 Lehigh/Central PA 163,026 — 163,026 138,766 2,280 141,046 131,168 2,305 133,473 Philadelphia 11,914 33,590 45,504 12,842 28,996 41,838 11,809 28,681 40,490 Southeastern PA 8,925 50,837 59,762 19,448 72,208 91,656 28,457 119,255 147,712 United Kingdom 10,369 3,548 13,917 10,775 2,601 13,376 12,104 3,031 15,135 Other 102,457 28,267 130,724 91,762 44,759 136,521 86,180 47,165 133,345 $ 547,204 $ 124,076 671,280 $ 529,268 $ 204,782 734,050 $ 514,896 $ 293,787 808,683 Reconciliation to total operating revenue Development service fee income 82,673 12,941 — Discontinued operations (34,035 ) (36,010 ) (34,813 ) Corporate other (140 ) (283 ) 90 Total operating revenue $ 719,778 $ 710,698 $ 773,960
Reconciliation of Assets from Segment to Consolidated	The Company's total assets by reportable segment as of December 31, 2017 and 2016 is as follows (in thousands): As of December 31, 2017 2016 Carolinas/Richmond $ 543,922 $ 503,920 Chicago/Minneapolis 615,186 616,298 Florida 533,861 514,431 Houston 498,584 530,438 Lehigh/Central PA 1,210,746 1,311,815 Philadelphia 665,843 557,510 Southeastern PA 241,128 262,155 United Kingdom 251,824 189,766 Other 1,807,653 1,403,431 Segment-level total assets 6,368,747 5,889,764 Corporate Other 71,010 103,049 Total assets $ 6,439,757 $ 5,992,813
Schedule of Long-Lived Assets, by Geographical Areas	The Company's real estate assets by reportable segment as of December 31, 2017 and 2016 is as follows (in thousands): As of December 31, 2017 2016 Carolinas/Richmond $ 491,634 $ 482,736 Chicago/Minneapolis 557,776 565,062 Florida 483,315 476,046 Houston 456,591 463,739 Lehigh/Central PA 1,118,802 1,234,091 Philadelphia 277,153 332,933 Southeastern PA 19,352 123,093 United Kingdom 191,542 149,082 Other 1,769,705 1,288,208 Total real estate assets $ 5,365,870 $ 5,114,990
Schedule of Expenditures on Long-Lived Assets	The Company incurred the following costs related to its long-lived assets for the years ended December 31, 2017 , 2016 and 2015 (in thousands): Year Ended December 31, 2017 2016 2015 Costs incurred on long-lived assets Carolinas/Richmond $ 31,958 $ 51,647 $ 31,175 Chicago/Minneapolis 14,246 29,317 54,742 Florida 23,832 38,312 43,594 Houston 17,522 25,831 98,559 Lehigh/Central PA 89,304 176,386 165,319 Philadelphia 30,685 57,691 34,122 Southeastern PA 9,737 4,824 5,700 United Kingdom 10,501 11,492 12,960 Other 404,253 107,500 125,412 Total costs incurred on long-lived assets $ 632,038 $ 503,000 $ 571,583

Accounting for the Impairment48

Accounting for the Impairment or Disposal of Long-Lived Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting for the Impairment or Disposal of Long-Lived Assets [Abstract]
Disposal Group, Including Discontinued Operations	Information on the operating properties the Company sold during the years ended December 31, 2017 , 2016 and 2015 is as follows: 2017 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Chicago/Minneapolis 3 — 136,110 $ 8,917 Florida — 16 — 13,256 Houston 1 42 206,808 36,145 Lehigh/Central PA 2 44 1,683,876 249,045 Southeastern PA 4 3 313,410 56,156 Other — 8 — 3,739 Total 10 113 2,340,204 $ 367,258 2016 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Chicago/Minneapolis 24 5 2,037,275 $ 199,825 Florida 51 12 3,509,641 505,828 Lehigh/Central PA 1 — 120,777 11,200 Philadelphia — 1 — 2,640 Southeastern PA 31 — 2,165,002 266,821 Other 18 18 1,631,295 224,241 Total 125 36 9,463,990 $ 1,210,555 2015 Sales Reportable Segment Number of Buildings Acres of Developable Land (unaudited) Leaseable Square Feet (unaudited) Gross Proceeds (in thousands) Carolinas/Richmond 22 3 1,319,299 $ 110,054 Chicago/Minneapolis 2 — 222,642 25,700 Florida 4 — 874,125 55,425 Southeastern PA 46 20 2,724,489 316,583 Other 7 — 569,618 37,371 Total 81 23 5,710,173 $ 545,133 A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands): For the Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Revenues $ 34,035 $ 36,010 $ 34,813 Operating expenses (14,014 ) (12,989 ) (12,309 ) Depreciation and amortization (6,753 ) (8,385 ) (8,711 ) Impairment charges - real estate assets (6,686 ) — (1,029 ) Interest and other income 58 133 23 Interest expense (2,239 ) (2,778 ) (2,222 ) Net income before gain on property dispositions 4,401 11,991 10,565 Gain on property dispositions 14,578 — — Net income 18,979 11,991 10,565 Noncontrolling interest - operating partnership (444 ) (282 ) (246 ) Income available to common shareholders $ 18,535 $ 11,709 $ 10,319 The following table illustrates aggregate balance sheet information for all held-for-sale properties (in thousands): December 31, 2017 December 31, 2016 Included in Continuing Operations Included in Discontinued Operations Total Included in Continuing Operations Included in Discontinued Operations Total Land and land improvements $ 3,476 $ 25,848 $ 29,324 $ — $ 34,406 $ 34,406 Buildings and improvements 80,738 163,195 243,933 — 217,833 217,833 Land held for development 863 — 863 4,548 — 4,548 Accumulated depreciation (11,785 ) (98,346 ) (110,131 ) — (106,933 ) (106,933 ) Deferred financing and leasing costs, net 2,210 3,502 5,712 — 6,355 6,355 Other assets 5,137 7,390 12,527 — 8,679 8,679 Total assets held for sale $ 80,639 $ 101,589 $ 182,228 $ 4,548 $ 160,340 $ 164,888 Total liabilities held for sale $ 1,153 $ 3,398 $ 4,551 $ — $ 8,079 $ 8,079 The following table illustrates the number of sold or held-for-sale properties included in, or excluded from, discontinued operations in this report: Held for Sale as of December 31, 2017 Sold during the year ended December 31, 2017 Total Properties included in discontinued operations 25 2 27 Properties included in continuing operations 2 8 10 Properties sold or classified as held for sale 27 10 37
Significant Sale	A summary of net income (excluding gain on sale) related to this portfolio is as follows (in thousands): Year Ended December 31, 2016 2015 Net income $ 48,609 $ 58,792 Noncontrolling interest - operating partnership (1,142 ) (1,370 ) Income available to common shareholders $ 47,467 $ 57,422
Asset Impairment Charges	The impairment losses are for operating properties or land parcels and were in the reportable segments and for the amounts as indicated below (in thousands): Year Ended December 31, Reportable Segment 2017 2016 2015 Carolinas/Richmond $ — $ — $ 13,755 Houston 10,632 — — Chicago/Minneapolis — 3,879 — Southeastern PA — — 2,328 Other — — 2,161 Total $ 10,632 $ 3,879 $ 18,244

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Gain (Loss)	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 year ended December 31, 2017 , 2016, and 2015 (in thousands): Year Ended December 31, 2017 December 31, 2016 December 31, 2015 Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss) $ 176 $ (648 ) $ (1,884 ) Amount of loss related to the effective portion reclassified to interest expense $ (453 ) $ (1,069 ) $ (1,396 ) Amount of gain (loss) related to the ineffective portion recognized in interest expense $ 168 $ (48 ) $ (91 )

Supplemental Disclosure to St50

Supplemental Disclosure to Statements of Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2017
Supplemental Disclosure to Statements of Cash Flows [Abstract]
Supplemental Disclosure to Statements of Cash Flows	The following are supplemental disclosures to the statements of cash flows for the years ended December 31, 2017 , 2016 and 2015 (amounts in thousands): 2017 2016 2015 Write-off of fully depreciated/amortized property and deferred costs - properties included in continuing operations $ 16,568 $ 23,331 $ 27,202 Write-off of fully depreciated/amortized property and deferred costs - properties included in discontinued operations 15,368 18,075 15,137 Write-off of depreciated property and deferred costs due to sale/demolition - properties included in continuing operations 15,760 461,480 252,017 Write-off of depreciated property and deferred costs due to sale/demolition - properties included in discontinued operations 17,335 — — Write-off of costs related to early debt extinguishment — 219 — Changes in accrued development capital expenditures - properties included in continuing operations 12,341 (11,274 ) 12,935 Changes in accrued development capital expenditures - properties included in discontinued operations — (94 ) (971 ) Unrealized gain (loss) on cash flow hedge 605 410 (488 ) Capitalized equity-based compensation 1,096 1,221 876 Redemption of noncontrolling interests - common units 152 132 —

Organization (Details)

Organization (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Ownership interest in operating partnership - Limited Partnership	97.70%
Liberty Comcast 1701 JFK Boulevard, LP [Member]
Variable Interest Entity [Line Items]
Ownership percentage	20.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | Other Investments [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Variable Interest Entity [Line Items]
Maximum exposure to loss	$ 17.3	$ 18.7

Summary of Significant Accoun52

Summary of Significant Accounting Policies Real Estate and Depreciation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Construction related payables	$ 49.3	$ 37.1
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Useful Life	40 years
Capital Improvements [Member[ | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	15 years
Capital Improvements [Member[ | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	20 years
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	5 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	10 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Compensation costs, capitalized	$ 5.5	$ 7.2	$ 5.5

Summary of Significant Accoun53

Summary of Significant Accounting Policies Investments in Unconsolidated Joint Ventures Valuation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment Losses, Investments [Abstract]
Impairment losses	$ 0	$ 0	$ 0

Summary of Significant Accoun54

Summary of Significant Accounting Policies Accounts Receivable/Deferred Rent Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Allowance for doubtful accounts receivable	$ 6.6	$ 7.3
Provision for doubtful accounts	$ 0.6	$ 0.6	$ 2

Summary of Significant Accoun55

Summary of Significant Accounting Policies Revenue Recognition (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Development service fee expense		$ 85,805	$ 12,165	$ 0
Previously Reported [Member] | Other Income [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Development service fee income	$ 3,789			6,159
Previously Reported [Member] | General and Administrative Expense [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Development service fee expense	$ 3,210			$ 3,730

Summary of Significant Accoun56

Summary of Significant Accounting Policies Deferred Financing and Leasing Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Capitalized compensation, leasing costs	$ 3.6	$ 3.8	$ 4.6

Summary of Significant Accoun57

Summary of Significant Accounting Policies Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Mortgage loans, net	$ 267,093	$ 276,650
Unsecured notes, net	2,283,513	2,280,286
Secured Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Long-term Debt [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	267,298	286,684
Unsecured Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Long-term Debt [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	$ 2,359,998	$ 2,340,762

Summary of Significant Accoun58

Summary of Significant Accounting Policies Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Percent distribution of REIT taxable income	100.00%
Income provision	$ 0
Number of years subequent to a failed REIT Qualifing Test the Company would not be Qualified as a REIT	4 years
Uncertain tax positions	$ 0
Penalties and interest	0	$ 0	$ 0
Penalties and interest accrued	0	0
Federal income tax basis	6,800,000,000	$ 6,500,000,000
Taxable REIT Subsidiary [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards	40,600,000
Valuation allowance	$ 40,600,000
Expiration dates	Jan. 1, 2018
Tax Year 2018 [Member] | Tax Cuts and Jobs Act [Member] | Taxable REIT Subsidiary [Member]
Income Tax Contingency [Line Items]
Effective income tax rate	21.00%
Cash [Member] | Tax Year 2018 [Member] | Tax Cuts and Jobs Act [Member] | Taxable REIT Subsidiary [Member]
Income Tax Contingency [Line Items]
Effective income tax rate for repatriation of foreign earnings	15.50%
Noncash [Member] | Tax Year 2018 [Member] | Tax Cuts and Jobs Act [Member] | Taxable REIT Subsidiary [Member]
Income Tax Contingency [Line Items]
Effective income tax rate for repatriation of foreign earnings	8.00%

Summary of Significant Accoun59

Summary of Significant Accounting Policies Recently Issued Accounting Standards (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities	$ 336,631,000	$ 341,062,000	$ 379,121,000
Net Cash Provided by (Used in) Investing Activities	(465,652,000)	614,927,000	(89,660,000)
Net Cash Provided by (Used in) Financing Activities	96,231,000	(939,507,000)	(331,860,000)
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Financing Activities	96,231,000	(939,507,000)	(331,860,000)
Accounting Standards Update 2016-09 [Member] | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Financing Activities	101,338,000	(934,135,000)	(327,627,000)
Accounting Standards Update 2016-09 [Member] | Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities	5,107,000	5,372,000	4,233,000
Net Cash Provided by (Used in) Financing Activities	(5,107,000)	(5,372,000)	(4,233,000)
Accounting Standards Update 2016-18 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities	336,631,000	341,062,000	379,121,000
Net Cash Provided by (Used in) Investing Activities	(465,652,000)	614,927,000	(89,660,000)
Accounting Standards Update 2016-18 [Member] | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities	331,337,000	333,021,000	385,366,000
Net Cash Provided by (Used in) Investing Activities	(465,652,000)	613,402,000	(89,660,000)
Accounting Standards Update 2016-18 [Member] | Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities	187,000	2,669,000	(10,478,000)
Net Cash Provided by (Used in) Investing Activities	$ 0	$ 1,525,000	$ 0

Summary of Significant Accoun60

Summary of Significant Accounting Policies Concentration of Credit Risk (Details)	12 Months Ended
	Dec. 31, 2017customer
Concentration Risk [Line Items]
Number of Customers	1,091
Sales Revenue, Net [Member] | Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	10.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of Customers	0
Concentration Risk, Percentage	4.60%

Income per Common Share of th61

Income per Common Share of the Trust (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Income from continuing operations net of noncontrolling interest									$ 263,805	$ 345,108	$ 229,164
Discontinued operations net of noncontrolling interest									18,535	11,709	10,319
Income available to common shareholders									$ 282,340	$ 356,817	$ 239,483
Weighted Average Shares
Income from continuing operations net of noncontrolling interest - basic (shares)									146,742	146,204	148,243
Dilutive shares/units for long-term compensation plans (shares)									799	685	600
Income from continuing operations net of noncontrolling interest - diluted (shares)									147,541	146,889	148,843
Per Share/Unit
Net income available to common shareholders - basic (USD per share/unit)	$ 0.87	$ 0.41	$ 0.35	$ 0.29	$ 1.33	$ 0.37	$ 0.34	$ 0.39
Per Share
Income per common share - diluted (USD per share/unit)	$ 0.87	$ 0.40	$ 0.35	$ 0.29	$ 1.33	$ 0.37	$ 0.34	$ 0.39
Common shares [Member]
Per Share/Unit
Income from continuing operations net of noncontrolling interest - basic (USD per share/unit)									$ 1.79	$ 2.36	$ 1.55
Discontinued operations net of noncontrolling interest - basic (USD per share/unit)									0.13	0.08	0.07
Net income available to common shareholders - basic (USD per share/unit)									1.92	2.44	1.62
Per Share
Income from continuing operations net of noncontrolling interest - diluted (USD per share/unit)									1.78	2.35	1.54
Discontinued operations net of noncontrolling interest - diluted (USD per share/unit)									0.13	0.08	0.07
Income per common share - diluted (USD per share/unit)									$ 1.91	$ 2.43	$ 1.61

Income per Common Share of th62

Income per Common Share of the Trust (Anti-Dilutive) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Option [Member]
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive options that were excluded from the computation of diluted income per common share	0	800	1,500

Income per Common Share of th63

Income per Common Share of the Trust (Exercise of Options) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Option [Member] | Common shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of option exercises in period	193,000	369,000	65,000

Income per Common Share of th64

Income per Common Share of the Trust (Units and Distributions) (Details) - Common shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Increase in shares of the Trust/units of general partner from the conversion of limited partners' units	9,826	9,044	14,491
Distributions per common share	$ 1.6	$ 1.90	$ 1.90

Income per Common Unit of the65

Income per Common Unit of the Operating Partnership (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Income from continuing operations net of noncontrolling interest									$ 263,805	$ 345,108	$ 229,164
Income from discontinued operations	$ 17,361	$ (2,809)	$ 2,308	$ 2,119	$ 3,253	$ 4,059	$ 2,242	$ 2,437	18,979	11,991	10,565
Income available to common shareholders									$ 282,340	$ 356,817	$ 239,483
Weighted Average Shares
Income from continuing operations net of noncontrolling interest - basic (shares)									146,742	146,204	148,243
Dilutive shares/units for long-term compensation plans (shares)									799	685	600
Income from continuing operations net of noncontrolling interest - diluted (shares)									147,541	146,889	148,843
Per Share/Unit
Net income available to common shareholders - basic (USD per share/unit)	$ 0.87	$ 0.41	$ 0.35	$ 0.29	$ 1.33	$ 0.37	$ 0.34	$ 0.39
Per Share
Income per common share - diluted (USD per share/unit)	$ 0.87	$ 0.40	$ 0.35	$ 0.29	$ 1.33	$ 0.37	$ 0.34	$ 0.39
Liberty Property Limited Partnership [Member]
Income
Income from continuing operations net of noncontrolling interest									$ 270,585	$ 353,896	$ 235,110
Less: Preferred unit distributions									(472)	(472)	(472)
Income from continuing operations available to common unitholders									270,113	353,424	234,638
Income from discontinued operations									18,979	11,991	10,565
Income available to common shareholders									$ 289,092	$ 365,415	$ 245,203
Weighted Average Shares
Income from continuing operations net of noncontrolling interest - basic (shares)									150,270	149,740	151,783
Dilutive shares/units for long-term compensation plans (shares)									799	685	600
Income from continuing operations net of noncontrolling interest - diluted (shares)									151,069	150,425	152,383
Liberty Property Limited Partnership [Member] | Common units [Member]
Per Share/Unit
Income from continuing operations net of noncontrolling interest - basic (USD per share/unit)									$ 1.79	$ 2.36	$ 1.55
Discontinued operations net of noncontrolling interest - basic (USD per share/unit)									0.13	0.08	0.07
Net income available to common shareholders - basic (USD per share/unit)									1.92	2.44	1.62
Per Share
Income from continuing operations net of noncontrolling interest - diluted (USD per share/unit)									1.78	2.35	1.54
Discontinued operations net of noncontrolling interest - diluted (USD per share/unit)									0.13	0.08	0.07
Income per common share - diluted (USD per share/unit)									$ 1.91	$ 2.43	$ 1.61

Income per Common Unit of the66

Income per Common Unit of the Operating Partnership (Anti-Dilutive) (Details) - Stock Option [Member] - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive options that were excluded from the computation of diluted income per common share	0	800	1,500
Liberty Property Limited Partnership [Member]
Antidilutive Options Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive options that were excluded from the computation of diluted income per common share	0	800	1,500

Income per Common Unit of the67

Income per Common Unit of the Operating Partnership (Exercise of Options) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Liberty Property Limited Partnership [Member] | Stock Option [Member] | Common units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of option exercises in period	193,000	369,000	65,000

Income per Common Unit of the68

Income per Common Unit of the Operating Partnership (Units and Distributions) (Details) - Liberty Property Limited Partnership [Member] - Common units [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Distributions per common unit	$ 1.6	$ 1.90	$ 1.90
Limited Partner [Member]
Class of Stock [Line Items]
Number of common units converted	9,826	9,044	14,491

Accumulated Other Comprehensi69

Accumulated Other Comprehensive Loss - (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning Balance		$ 3,062,923	$ 3,030,254
Ending Balance		3,148,366	3,062,923
Total equity		3,062,923	3,030,254	$ 3,148,366	$ 3,062,923	$ 3,106,312
Total accumulated other comprehensive loss included in shareholders' equity				3,087,358	3,003,391
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning Balance		(56,767)	(22,023)
Other comprehensive income (loss), before reclassifications		18,066	(34,744)
Ending Balance		(38,701)	(56,767)
Total equity		(56,767)	(22,023)	(38,701)	(56,767)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning Balance		(455)	(865)
Other comprehensive income (loss), before reclassifications		152	(659)
Reclassification adjustment	[1]	453	1,069
Ending Balance		150	(455)
Total equity		(455)	(865)	150	(455)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning Balance		(57,222)
Ending Balance		(38,551)	(57,222)
Total equity		(57,222)	(57,222)	(38,551)	(57,222)
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning Balance		1,191
Ending Balance		754	1,191
Total equity		1,191	1,191	754	1,191
AOCI Attributable to Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning Balance		(56,031)	(22,506)
Ending Balance		(37,797)	(56,031)
Total equity		$ (56,031)	$ (22,506)	(37,797)	(56,031)	$ (9,784)
Total accumulated other comprehensive loss included in shareholders' equity				$ (37,797)	$ (56,031)
[1]	(1)Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.

Real Estate (Carrying Value of

Real Estate (Carrying Value of Properties) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Real Estate Investment Property, at Cost [Abstract]
Land and Land Improvements	$ 1,153,680	$ 1,060,065
Building and improvements	4,443,583	4,298,012
Accumulated Depreciation	940,613	847,106
Total Real Estate	5,597,263	5,358,077
Depreciation	148,900	166,800	$ 181,000
Industrial Property [Member]
Real Estate Investment Property, at Cost [Abstract]
Land and Land Improvements	1,001,454	914,428
Building and improvements	3,873,830	3,725,331
Accumulated Depreciation	814,301	719,658
Total Real Estate	4,875,284	4,639,759
Office Building [Member]
Real Estate Investment Property, at Cost [Abstract]
Land and Land Improvements	152,226	145,637
Building and improvements	569,753	572,681
Accumulated Depreciation	126,312	127,448
Total Real Estate	$ 721,979	$ 718,318

Real Estate (Real Estate Proper

Real Estate (Real Estate Properties Sold) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²abldg	Dec. 31, 2016USD ($)ft²abldg	Dec. 31, 2015USD ($)ft²abldg
Disposition Disclosures [Line Items]
Number of buildings | bldg	37
Acres of developable land	9
Gross proceeds | $	$ 379,139	$ 1,192,918	$ 530,440
Building and Building Improvements [Member] | United Kingdom [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	0
Leaseable square feet | ft²	0
Land and Land Improvements [Member] | Philadelphia [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		6
Land and Land Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		8
Land and Land Improvements [Member] | United Kingdom [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	35
Land and Land Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		6
2016 sales [Member] | Richmond Hampton Roads Sale [Member] | Immediate Family Member of Management or Principal Owner [Member] | Building and Building Improvements [Member] | Carolinas Richmond [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			22
2016 sales [Member] | Richmond Hampton Roads Sale [Member] | Immediate Family Member of Management or Principal Owner [Member] | Land and Land Improvements [Member] | Carolinas Richmond [Member]
Disposition Disclosures [Line Items]
Acres of developable land			3
2016 sales [Member] | Richmond Hampton Roads Sale [Member] | Immediate Family Member of Management or Principal Owner [Member] | Land, Buildings and Improvements [Member] | Carolinas Richmond [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			$ 110,300
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		125
Leaseable square feet | ft²		9,463,990
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		51
Leaseable square feet | ft²		3,509,641
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Lehigh Central PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		1
Leaseable square feet | ft²		120,777
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Philadelphia [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		0
Leaseable square feet | ft²		0
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		18
Leaseable square feet | ft²		1,631,295
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		31
Leaseable square feet | ft²		2,165,002
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg		24
Leaseable square feet | ft²		2,037,275
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		36
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		12
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Lehigh Central PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		0
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Philadelphia [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		1
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		18
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		0
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land		5
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		$ 1,210,555
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		505,828
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Lehigh Central PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		11,200
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Philadelphia [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		2,640
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		224,241
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		266,821
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $		199,825
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			81
Leaseable square feet | ft²			5,710,173
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			4
Leaseable square feet | ft²			874,125
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			7
Leaseable square feet | ft²			569,618
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Southeastern PA [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			41
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			46
Leaseable square feet | ft²			2,724,489
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Carolinas Richmond [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			22
Leaseable square feet | ft²			1,319,299
Not Discontinued Operations [Member] | 2016 sales [Member] | Building and Building Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg			2
Leaseable square feet | ft²			222,642
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land			23
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land			0
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land			0
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Southeastern PA [Member]
Disposition Disclosures [Line Items]
Acres of developable land			20
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land			20
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Carolinas Richmond [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land			3
Not Discontinued Operations [Member] | 2016 sales [Member] | Land and Land Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land			0
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			$ 545,133
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			55,425
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			37,371
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Southeastern PA [Member]
Disposition Disclosures [Line Items]
Gain on sale of property | $		$ 14,300
Gain (Loss) on Disposition of Property Plant Equipment | $	$ 14,300
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			316,583
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Carolinas Richmond [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			110,054
Not Discontinued Operations [Member] | 2016 sales [Member] | Land, Buildings and Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $			$ 25,700
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	10
Leaseable square feet | ft²	2,340,204
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	0
Leaseable square feet | ft²	0
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Houston [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	1
Leaseable square feet | ft²	206,808
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Lehigh Central PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	2
Leaseable square feet | ft²	1,683,876
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	0
Leaseable square feet | ft²	0
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	4
Leaseable square feet | ft²	313,410
Not Discontinued Operations [Member] | 2017 sales [Member] | Building and Building Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Number of buildings | bldg	3
Leaseable square feet | ft²	136,110
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	113
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	16
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Houston [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	42
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Lehigh Central PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	44
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	8
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	3
Not Discontinued Operations [Member] | 2017 sales [Member] | Land and Land Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Acres of developable land	0
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	$ 367,258
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Florida [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	13,256
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Houston [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	36,145
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Lehigh Central PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	249,045
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Other Segments [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	3,739
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Southeastern PA [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	56,156
Not Discontinued Operations [Member] | 2017 sales [Member] | Land, Buildings and Improvements [Member] | Chicago Minneapolis [Member] | Operating Segments [Member]
Disposition Disclosures [Line Items]
Gross proceeds | $	$ 8,917

Real Estate (Real Estate Prop72

Real Estate (Real Estate Properties Acquired) (Details) $ in Thousands	2 Months Ended	12 Months Ended
	Feb. 27, 2018USD ($)	Dec. 31, 2017USD ($)ft²abldg	Dec. 31, 2016USD ($)ft²abldg	Dec. 31, 2015USD ($)ft²abldg	Jan. 01, 2018ft²
Business Acquisition [Line Items]
Number of buildings | bldg		37
Acres of developable land | a		9
Operating Segments [Member] | Building and Building Improvements [Member] | United Kingdom [Member]
Business Acquisition [Line Items]
Number of buildings | bldg		0
Leaseable square feet | ft²		0
Operating Segments [Member] | Land and Land Improvements [Member] | Chicago Minneapolis [Member]
Business Acquisition [Line Items]
Acres of developable land | a			6
Operating Segments [Member] | Land and Land Improvements [Member] | Philadelphia [Member]
Business Acquisition [Line Items]
Acres of developable land | a			6
Operating Segments [Member] | Land and Land Improvements [Member] | Southeastern PA [Member]
Business Acquisition [Line Items]
Acres of developable land | a			8
Operating Segments [Member] | Land and Land Improvements [Member] | United Kingdom [Member]
Business Acquisition [Line Items]
Acres of developable land | a		35
2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member]
Business Acquisition [Line Items]
Number of buildings | bldg				5
Leaseable square feet | ft²				1,529,211
2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Number of buildings | bldg				0
Leaseable square feet | ft²				0
2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Chicago Minneapolis [Member]
Business Acquisition [Line Items]
Number of buildings | bldg				1
Leaseable square feet | ft²				197,956
2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Number of buildings | bldg				0
Leaseable square feet | ft²				0
2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Number of buildings | bldg				1
Leaseable square feet | ft²				410,059
2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Houston [Member]
Business Acquisition [Line Items]
Number of buildings | bldg				3
Leaseable square feet | ft²				921,196
2015 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member]
Business Acquisition [Line Items]
Acres of developable land | a				758
2015 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Acres of developable land | a				94
2015 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Chicago Minneapolis [Member]
Business Acquisition [Line Items]
Acres of developable land | a				188
2015 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Acres of developable land | a				281
2015 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Acres of developable land | a				56
2015 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Houston [Member]
Business Acquisition [Line Items]
Acres of developable land | a				139
2015 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member]
Business Acquisition [Line Items]
Purchase price | $				$ 220,415
2015 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Purchase price | $				1,727
2015 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Chicago Minneapolis [Member]
Business Acquisition [Line Items]
Purchase price | $				24,541
2015 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Purchase price | $				62,402
2015 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Purchase price | $				45,248
2015 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Houston [Member]
Business Acquisition [Line Items]
Purchase price | $				$ 86,497
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			1
Leaseable square feet | ft²			73,160
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			0
Leaseable square feet | ft²			0
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Chicago Minneapolis [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			1
Leaseable square feet | ft²			73,160
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			0
Leaseable square feet | ft²			0
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Philadelphia [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			0
Leaseable square feet | ft²			0
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Southeastern PA [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			0
Leaseable square feet | ft²			0
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Number of buildings | bldg			0
Leaseable square feet | ft²			0
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member]
Business Acquisition [Line Items]
Acres of developable land | a			217
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Acres of developable land | a			13
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Acres of developable land | a			76
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Acres of developable land | a			108
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member]
Business Acquisition [Line Items]
Purchase price | $			$ 60,892
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Purchase price | $			2,251
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Chicago Minneapolis [Member]
Business Acquisition [Line Items]
Purchase price | $			11,064
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Purchase price | $			15,395
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Philadelphia [Member]
Business Acquisition [Line Items]
Purchase price | $			13,943
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Southeastern PA [Member]
Business Acquisition [Line Items]
Purchase price | $			3,344
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Purchase price | $			$ 14,895
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member]
Business Acquisition [Line Items]
Number of buildings | bldg		8
Leaseable square feet | ft²		1,861,879
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Number of buildings | bldg		0
Leaseable square feet | ft²		0
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Number of buildings | bldg		0
Leaseable square feet | ft²		0
2016 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Number of buildings | bldg		8
Leaseable square feet | ft²		1,861,879
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member]
Business Acquisition [Line Items]
Acres of developable land | a		254
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Acres of developable land | a		11
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Acres of developable land | a		95
2016 acquisitions [Member] | Operating Segments [Member] | Land and Land Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Acres of developable land | a		113
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member]
Business Acquisition [Line Items]
Purchase price | $		$ 296,398
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Carolinas Richmond [Member]
Business Acquisition [Line Items]
Purchase price | $		1,242
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Lehigh Central PA [Member]
Business Acquisition [Line Items]
Purchase price | $		17,798
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | United Kingdom [Member]
Business Acquisition [Line Items]
Purchase price | $		12,550
2016 acquisitions [Member] | Operating Segments [Member] | Land, Buildings and Improvements [Member] | Other Segments [Member]
Business Acquisition [Line Items]
Purchase price | $		$ 264,808
Subsequent Event [Member] | 2015 acquisitions [Member] | Operating Segments [Member] | Building and Building Improvements [Member] | Southern California [Member]
Business Acquisition [Line Items]
Leaseable square feet | ft²					400,000
Purchase price | $	$ 92,700

Investments in Unconsolidated73

Investments in Unconsolidated Joint Ventures (Liberty Venture I, LP) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²abldgproperties	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)ft²bldg
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	37
Gross proceeds	$ 379,139	$ 1,192,918	$ 530,440
Acres of developable land | a	9
New Jersey [Member] | Liberty Venture I, LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Leaseable square feet | ft²	4,500,000
Building and Building Improvements [Member] | New Jersey [Member] | Liberty Venture I, LP [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²			198,000
Gross proceeds			$ 8,500
Construction in Progress [Member] | New Jersey [Member] | Liberty Venture I, LP [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties	1
Leaseable square feet | ft²	302,000
Anticipated aggregate investment	$ 21,100
Industrial Property [Member] | Building and Building Improvements [Member] | New Jersey [Member] | Liberty Venture I, LP [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties	28
Joint venture sales, 2015 [Member] | Building and Building Improvements [Member] | New Jersey [Member] | Liberty Venture I, LP [Member] | Not Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg			1
Equity Method Investee [Member] | Liberty Venture I, LP [Member] | New Jersey [Member]
Schedule of Equity Method Investments [Line Items]
Management fees revenue	$ 1,600	2,300	$ 1,600
Prepaid Expenses and Other Current Assets [Member] | Equity Method Investee [Member] | Liberty Venture I, LP [Member] | New Jersey [Member]
Schedule of Equity Method Investments [Line Items]
Due from related parties	$ 223	$ 250

Investments in Unconsolidated74

Investments in Unconsolidated Joint Ventures (Kings Hill Unit Trust) (Details) ft² in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²bldgproperties	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	37
United Kingdom [Member] | Kings Hill Unit Trust [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%
United Kingdom [Member] | Kings Hill Unit Trust [Member] | Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Note receivable interest rate	10.00%
Management fees revenue	$ 302	$ 293	$ 304
United Kingdom [Member] | Building and Building Improvements [Member] | Kings Hill Unit Trust [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²	489
United Kingdom [Member] | Building and Building Improvements [Member] | Office Building [Member] | Kings Hill Unit Trust [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties	14
Investments in and advances to unconsolidated joint ventures [Member] | United Kingdom [Member] | Kings Hill Unit Trust [Member] | Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Notes receivable	$ 4,700	4,100
Prepaid Expenses and Other Current Assets [Member] | United Kingdom [Member] | Kings Hill Unit Trust [Member] | Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Due from related parties	$ 122	$ 121

Investments in Unconsolidated75

Investments in Unconsolidated Joint Ventures (Liberty Illinois, LP) (Details) ft² in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²abldgproperties	Dec. 31, 2016USD ($)ft²bldg	Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	37
Acres of developable land | a	9
Gain (loss) on sale of properties	$ 114,965	$ 219,270	$ 100,314
Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member] | Liberty Illinois, LP [Member] | Not Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg		4
Leaseable square feet | ft²		636
Proceeds from sale of property		$ 32,500
Gain (Loss) on Investments [Member] | General Partner [Member] | Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member] | Liberty Illinois, LP [Member] | Not Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Gains on sale of land and building		1,000
Chicago Minneapolis [Member] | Liberty Illinois, LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Chicago Minneapolis [Member] | Building and Building Improvements [Member] | Liberty Illinois, LP [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²	4,900
Chicago Minneapolis [Member] | Building and Building Improvements [Member] | Industrial Property [Member] | Liberty Illinois, LP [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties	12
Chicago Minneapolis [Member] | Land and Land Improvements [Member] | Liberty Illinois, LP [Member]
Schedule of Equity Method Investments [Line Items]
Acres of developable land | a	248
Liberty Illinois, LP [Member] | Chicago Minneapolis [Member] | Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Management fees revenue	$ 900	1,000	$ 1,300
Prepaid Expenses and Other Current Assets [Member] | Liberty Illinois, LP [Member] | Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Due from related parties	$ 5	$ 132

Investments in Unconsolidated76

Investments in Unconsolidated Joint Ventures (Liberty Washington, LP) (Details) ft² in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²abldgproperties	Dec. 31, 2016USD ($)ft²aproperties	Dec. 31, 2015USD ($)ft²properties
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	37
Acres of developable land | a	9
Gain (loss) on debt extinguishment	$ (49)	$ (27,099)	$ 0
Gain (loss) on sale of properties	114,965	219,270	100,314
Gross proceeds	379,139	1,192,918	530,440
Impairment - real estate assets	$ 3,946	$ 3,879	$ 17,215
Discontinued Operations, Disposed of by Sale [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	2
Northern Virginia and Washington DC [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Building and Building Improvements [Member] | Northern Virginia and Washington DC [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²	451
Building and Building Improvements [Member] | Northern Virginia and Washington DC [Member] | Office Building [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties	2
Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member] | Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Sale [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties		12
Leaseable square feet | ft²		1,200
Proceeds from sale of property		$ 187,200
Joint venture, 2016 sales current quarter [Member] | Land and Land Improvements [Member] | Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Sale [Member]
Schedule of Equity Method Investments [Line Items]
Acres of developable land | a		6
Joint venture, 2016 transfer to lender [Member] | Building and Building Improvements [Member] | Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Means Other than Sale [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties		6
Leaseable square feet | ft²		698
Joint venture sales, 2015 [Member] | Building and Building Improvements [Member] | Northern Virginia [Member] | Liberty Washington, LP [Member] | Not Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | properties			1
Leaseable square feet | ft²			80
Gross proceeds			$ 5,000
Mortgages [Member] | Joint venture, 2016 transfer to lender [Member] | Building and Building Improvements [Member] | Liberty Washington, LP [Member] | Discontinued Operations, Disposed of by Means Other than Sale [Member]
Schedule of Equity Method Investments [Line Items]
Extinguishment of debt		$ 112,500
Gain (Loss) on Investments [Member] | Northern Virginia [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Impairment - real estate assets			56,800
Equity Method Investee [Member] | DC Metro [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Impairment - real estate assets	$ 15,900
General Partner [Member] | Gain (Loss) on Investments [Member] | Northern Virginia [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Impairment - real estate assets			11,500
General Partner [Member] | Gain (Loss) on Investments [Member] | Joint venture, 2016 sales current quarter [Member] | Building and Building Improvements [Member] | Liberty Washington, LP [Member] | Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Gains on sale of land and building		6,000
General Partner [Member] | Gain (Loss) on Investments [Member] | Mortgages [Member] | Joint venture, 2016 transfer to lender [Member] | Building and Building Improvements [Member] | Liberty Washington, LP [Member] | Discontinued Operations [Member]
Schedule of Equity Method Investments [Line Items]
Gain (loss) on debt extinguishment		4,200
Liberty Washington, LP [Member] | Equity Method Investee [Member] | Northern Virginia and Washington DC [Member]
Schedule of Equity Method Investments [Line Items]
Management fees revenue	1,100	2,000	$ 4,800
Prepaid Expenses and Other Current Assets [Member] | Liberty Washington, LP [Member] | Equity Method Investee [Member] | Northern Virginia and Washington DC [Member]
Schedule of Equity Method Investments [Line Items]
Due from related parties	316	$ 322
Investments in and advances to unconsolidated joint ventures [Member] | General Partner [Member] | Equity Method Investee [Member] | DC Metro [Member] | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Impairment - real estate assets	$ 4,000

Investments in Unconsolidated77

Investments in Unconsolidated Joint Ventures (Liberty/Comcast 1701 JFK Boulevard, LP) (Details) ft² in Thousands, $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2018USD ($)	Dec. 31, 2017USD ($)ft²	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Repayments of Secured Debt		$ 7,795	$ 29,538	$ 175,364
Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage		20.00%
Philadelphia [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage		20.00%
Philadelphia [Member] | Equity Method Investee [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Management fees revenue		$ 2,700	2,700	$ 2,700
Philadelphia [Member] | Building and Building Improvements [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²		1,250
Philadelphia [Member] | Investments in and advances to unconsolidated joint ventures [Member] | Equity Method Investee [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Due to related parties		$ 59	59
Philadelphia [Member] | Prepaid Expenses and Other Current Assets [Member] | Equity Method Investee [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Due from related parties		$ 272	$ 401
Subsequent Event [Member] | Philadelphia [Member] | Equity Method Investee [Member] | Liberty Comcast 1701 JFK Boulevard, LP [Member]
Schedule of Equity Method Investments [Line Items]
Repayments of Secured Debt	$ 305,200

Investments in Unconsolidated78

Investments in Unconsolidated Joint Ventures (Liberty Property 18th & Arch LP and Liberty Property 18th & Arch Hotel, LP) (Details) ft² in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²	Dec. 31, 2016USD ($)ft²condominium_unit	Dec. 31, 2015USD ($)	Jun. 30, 2014USD ($)ft²roomstoryinvestment
Schedule of Equity Method Investments [Line Items]
Operating Income (Loss)	$ 236,644,000	$ 240,466,000	$ 244,368,000
Maximum exposure to loss	288,456,000	245,078,000
Development in progress	378,472,000	267,450,000
Gain (loss) on sale of properties	114,965,000	$ 219,270,000	100,314,000
Liberty Property 18th & Arch [Member]
Schedule of Equity Method Investments [Line Items]
Maximum exposure to loss	$ 177,800,000
Philadelphia [Member] | Liberty Property 18th & Arch [Member]
Schedule of Equity Method Investments [Line Items]
Number of equity method investments | investment				2
Anticipated investment in joint ventures				$ 190,700,000
Ownership percentage				20.00%
Philadelphia [Member] | Construction in Progress [Member] | Liberty Property 18th & Arch [Member]
Schedule of Equity Method Investments [Line Items]
Number of stories in a high-rise building | story				60
Leaseable square feet | ft²	300			1,300
Number of hotel rooms | room				217
Anticipated aggregate investment	$ 354,100,000			$ 953,700,000
Philadelphia [Member] | Building and Building Improvements [Member] | Liberty Property 18th & Arch [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²	1,100
Anticipated aggregate investment	$ 599,600,000
Liberty Property 18th & Arch [Member]
Schedule of Equity Method Investments [Line Items]
Leaseable square feet | ft²		15
Number of Residential Condominium Units | condominium_unit		3
Proceeds from sale of property		$ 14,300,000
Gain (loss) on sale of properties		300,000
Liberty Property 18th & Arch [Member] | Equity Method Investee [Member] | Philadelphia [Member]
Schedule of Equity Method Investments [Line Items]
Management fees revenue	200,000	100,000	100,000
Liberty Property 18th & Arch [Member] | Equity Method Investee [Member] | Prepaid Expenses and Other Current Assets [Member] | Philadelphia [Member]
Schedule of Equity Method Investments [Line Items]
Due from related parties	466,000	1,300,000
Liberty Property 18th & Arch [Member] | Equity Method Investee [Member] | Operating Income (Loss) [Member] | Philadelphia [Member]
Schedule of Equity Method Investments [Line Items]
Operating Income (Loss)	$ (3,500,000)
Liberty Property 18th & Arch [Member] | Equity Method Investee [Member] | Other Income [Member] | Philadelphia [Member]
Schedule of Equity Method Investments [Line Items]
Operating Income (Loss)		$ 600,000	$ 1,600,000

Investments in Unconsolidated79

Investments in Unconsolidated Joint Ventures (Other Joint Ventures) (Details) ft² in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²abldginvestmentproperties	Dec. 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	37
Acres of developable land | a	9
Philadelphia [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%
Building and Building Improvements [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%
Building and Building Improvements [Member] | Orlando [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Number of equity method investments | investment	3
Number of properties | properties	7
Building and Building Improvements [Member] | United Kingdom [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of joint venture		$ 13,700
Loss on sale of join venture		6
Building and Building Improvements [Member] | Philadelphia [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties | bldg	1
Leaseable square feet | ft²	48
Purchase price	$ 15,000
Land and Land Improvements [Member] | Philadelphia [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Acres of developable land | a	1
Investments in and advances to unconsolidated joint ventures [Member] | Cambridge Medipark Ltd [Member] | Equity Method Investee [Member] | United Kingdom [Member] | Other Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Notes payable	$ 2,500	$ 2,300

Investments in Unconsolidated80

Investments in Unconsolidated Joint Ventures (Summary Financial Data) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Real estate assets		$ 2,056,711	$ 1,473,229
Accumulated depreciation		(339,215)	(300,503)
Real estate assets, net		1,717,496	1,172,726
Development in progress		308,104	677,918
Land held for development		74,575	73,826
Other assets		238,791	200,663
Total assets		2,338,966	2,125,133
Liabilities and Equity
Debt		869,141	846,328
Other liabilities		165,565	166,697
Equity		1,304,260	1,112,108
Total liabilities and equity		2,338,966	2,125,133
Company's net investment in unconsolidated joint ventures	[1]	288,456	245,078
Condensed Statements of Operations
Total revenue		186,239	178,876	$ 211,327
Operating expense		63,249	67,427	82,565
Operating income (loss)		122,990	111,449	128,762
Interest		(40,295)	(47,044)	(59,509)
Depreciation and amortization		(44,366)	(44,709)	(54,766)
Other income (expense)		14,437	8,474	55,960
Gain (loss) on sale/impairment		(15,880)	45,000	(56,032)
Net income (loss)		36,886	73,170	14,415
Company's equity in earnings (loss) of unconsolidated joint ventures		17,155	21,970	3,149
Difference between carrying amount and underlying equity		(3,000)	1,400
Liberty Venture I, LP [Member]
Assets
Real estate assets		229,600	226,313
Accumulated depreciation		(48,629)	(42,779)
Real estate assets, net		180,971	183,534
Development in progress		18,337	6,886
Land held for development		0	0
Other assets		20,722	23,494
Total assets		220,030	213,914
Liabilities and Equity
Debt		166,295	154,386
Other liabilities		4,117	6,673
Equity		49,618	52,855
Total liabilities and equity		220,030	213,914
Company's net investment in unconsolidated joint ventures	[1]	10,425	11,175
Condensed Statements of Operations
Total revenue		31,079	25,149	23,708
Operating expense		8,101	6,835	7,977
Operating income (loss)		22,978	18,314	15,731
Interest		(5,801)	(4,182)	(5,415)
Depreciation and amortization		(7,598)	(6,375)	(6,399)
Other income (expense)		(100)	50	68
Gain (loss) on sale/impairment		0	0	760
Net income (loss)		9,479	7,807	4,745
Company's equity in earnings (loss) of unconsolidated joint ventures		2,914	2,332	1,540
Kings Hill Unit Trust [Member]
Assets
Real estate assets		152,998	137,960
Accumulated depreciation		(30,028)	(26,872)
Real estate assets, net		122,970	111,088
Development in progress		0	0
Land held for development		0	0
Other assets		10,957	9,603
Total assets		133,927	120,691
Liabilities and Equity
Debt		92,131	83,846
Other liabilities		28,056	24,513
Equity		13,740	12,332
Total liabilities and equity		133,927	120,691
Company's net investment in unconsolidated joint ventures	[1]	6,100	5,349
Condensed Statements of Operations
Total revenue		12,976	11,926	12,602
Operating expense		4,756	4,854	5,261
Operating income (loss)		8,220	7,072	7,341
Interest		(2,329)	(2,554)	(6,116)
Depreciation and amortization		(3,238)	(3,557)	(3,954)
Other income (expense)		(4)	(77)	45,604
Gain (loss) on sale/impairment		0	0	0
Net income (loss)		2,649	884	42,875
Company's equity in earnings (loss) of unconsolidated joint ventures		660	275	(425)
Liberty Illinois, LP [Member]
Assets
Real estate assets		252,593	251,765
Accumulated depreciation		(57,444)	(51,901)
Real estate assets, net		195,149	199,864
Development in progress		0	0
Land held for development		33,500	31,567
Other assets		16,337	19,036
Total assets		244,986	250,467
Liabilities and Equity
Debt		138,869	137,294
Other liabilities		7,548	8,433
Equity		98,569	104,740
Total liabilities and equity		244,986	250,467
Company's net investment in unconsolidated joint ventures	[1]	14,980	15,339
Condensed Statements of Operations
Total revenue		23,711	26,599	26,085
Operating expense		7,989	9,961	9,303
Operating income (loss)		15,722	16,638	16,782
Interest		(5,882)	(7,243)	(8,441)
Depreciation and amortization		(6,918)	(7,589)	(7,406)
Other income (expense)		(71)	64	29
Gain (loss) on sale/impairment		0	4,068	0
Net income (loss)		2,851	5,938	964
Company's equity in earnings (loss) of unconsolidated joint ventures		2,118	2,065	807
Liberty Washington, LP [Member]
Assets
Real estate assets		274,847	289,627
Accumulated depreciation		(49,106)	(44,235)
Real estate assets, net		225,741	245,392
Development in progress		0	0
Land held for development		0	0
Other assets		18,566	18,749
Total assets		244,307	264,141
Liabilities and Equity
Debt		102,624	103,667
Other liabilities		4,954	4,385
Equity		136,729	156,089
Total liabilities and equity		244,307	264,141
Company's net investment in unconsolidated joint ventures	[1]	34,107	38,863
Condensed Statements of Operations
Total revenue		25,439	39,727	71,101
Operating expense		9,147	15,935	27,384
Operating income (loss)		16,292	23,792	43,717
Interest		(4,065)	(10,866)	(17,353)
Depreciation and amortization		(5,926)	(10,750)	(20,725)
Other income (expense)		(65)	257	531
Gain (loss) on sale/impairment		(15,910)	40,943	(56,792)
Net income (loss)		(9,674)	43,376	(50,622)
Company's equity in earnings (loss) of unconsolidated joint ventures		(1,941)	10,857	(7,314)
Liberty Comcast 1701 JFK Boulevard, LP [Member]
Assets
Real estate assets		496,210	495,842
Accumulated depreciation		(138,943)	(125,014)
Real estate assets, net		357,267	370,828
Development in progress		0	0
Land held for development		0	0
Other assets		49,755	48,074
Total assets		407,022	418,902
Liabilities and Equity
Debt		305,223	309,475
Other liabilities		9,488	9,964
Equity		92,311	99,463
Total liabilities and equity		407,022	418,902
Company's net investment in unconsolidated joint ventures	[1]	17,307	18,688
Condensed Statements of Operations
Total revenue		65,372	65,587	68,444
Operating expense		26,474	26,761	29,692
Operating income (loss)		38,898	38,826	38,752
Interest		(19,411)	(19,737)	(19,936)
Depreciation and amortization		(14,485)	(14,513)	(14,442)
Other income (expense)		(325)	(213)	(227)
Gain (loss) on sale/impairment		0	0	0
Net income (loss)		4,677	4,363	4,147
Company's equity in earnings (loss) of unconsolidated joint ventures		1,659	1,594	2,053
Liberty Property 18th & Arch [Member]
Assets
Real estate assets	[2]	551,874	0
Accumulated depreciation	[2]	(4,070)	0
Real estate assets, net	[2]	547,804	0
Development in progress	[2]	289,767	671,032
Land held for development	[2]	0	0
Other assets	[2]	98,191	52,053
Total assets	[2]	935,762	723,085
Liabilities and Equity
Debt	[2]	0	0
Other liabilities	[2]	102,982	95,574
Equity	[2]	832,780	627,511
Total liabilities and equity	[2]	935,762	723,085
Company's net investment in unconsolidated joint ventures	[1],[2]	177,843	132,952
Condensed Statements of Operations
Total revenue	[2]	16,544	0	0
Operating expense	[2]	3,417	280	221
Operating income (loss)	[2]	13,127	(280)	(221)
Interest	[2]	0	0	0
Depreciation and amortization	[2]	(4,077)	0	0
Other income (expense)	[2]	(547)	1,270	30
Gain (loss) on sale/impairment	[2]	30	0	0
Net income (loss)	[2]	8,533	990	(191)
Company's equity in earnings (loss) of unconsolidated joint ventures	[2]	1,782	213	(29)
Other Joint Ventures [Member]
Assets
Real estate assets		98,589	71,722
Accumulated depreciation		(10,995)	(9,702)
Real estate assets, net		87,594	62,020
Development in progress		0	0
Land held for development		41,075	42,259
Other assets		24,263	29,654
Total assets		152,932	133,933
Liabilities and Equity
Debt		63,999	57,660
Other liabilities		8,420	17,155
Equity		80,513	59,118
Total liabilities and equity		152,932	133,933
Company's net investment in unconsolidated joint ventures	[1]	27,694	22,712
Condensed Statements of Operations
Total revenue	[3]	11,118	9,888	9,387
Operating expense	[3]	3,365	2,801	2,727
Operating income (loss)	[3]	7,753	7,087	6,660
Interest	[3]	(2,807)	(2,462)	(2,248)
Depreciation and amortization	[3]	(2,124)	(1,925)	(1,840)
Other income (expense)	[3]	15,549	7,123	9,925
Gain (loss) on sale/impairment	[3]	0	(11)	0
Net income (loss)	[3]	18,371	9,812	12,497
Company's equity in earnings (loss) of unconsolidated joint ventures	[3]	9,963	4,634	6,517
Cambridge Medipark Ltd [Member] | Leaseholds and Leasehold Improvements [Member]
Condensed Statements of Operations
Gain (loss) on sale/impairment		$ 16,000	$ 7,100	$ 9,900
[1]	Differences between the Company's net investment in unconsolidated joint ventures and its underlying equity in the net assets of the venture are primarily a result of impairments related to the Company's investment in unconsolidated joint ventures, the deferral of gains associated with the sales of properties to joint ventures in which the Company retains an ownership interest and loans made to the joint ventures by the Company. These adjustments have resulted in an aggregate difference reducing the Company's investments in unconsolidated joint ventures by $3.0 million and $1.4 million as of December 31, 2017 and 2016, respectively. Differences between historical cost basis and the basis reflected at the joint venture level (other than loans) are typically depreciated over the life of the related asset.
[2]	Represents the combined results of two joint ventures related to the property at 18th and Arch Streets, Philadelphia.
[3]	Other income/(expense) for this group of joint ventures reflects gains related to the sales of land leasehold interests totaling $16.0 million, $7.1 million and $9.9 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Deferred Financing and Leasin81

Deferred Financing and Leasing Costs (Deferred Financing and Leasing Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-lived intangible assets
Deferred financing costs	$ 17,044	$ 11,917
Deferred leasing costs	198,767	179,161
Market value intangible	18,802	19,451
Origination value intangible	90,116	83,485
Finite-lived intangible assets, gross	324,729	294,014
Accumulated amortization:
Deferred financing costs	(11,002)	(10,152)
Deferred leasing costs	(80,434)	(70,842)
Market value intangible	(14,324)	(12,625)
Origination value intangible	(59,719)	(53,357)
Finite-lived intangible assets, accumulated amortization	(165,479)	(146,976)
Deferred financing and leasing costs, net	159,250	147,038
Amortization of deferred financing costs	3,750	3,974	$ 4,395
Amortization of intangible assets	$ 31,600	$ 37,100	$ 44,200

Deferred Financing and Leasin82

Deferred Financing and Leasing Costs (Finite-Lived Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Unamortized market value intangible liabilities	$ 9.6	$ 4.4
Amortization of above and below Market Leases	$ (1.3)	$ (1.6)	$ (1.9)
Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Remaining amortization period	3 years 1 month 25 days
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Remaining amortization period	5 years 6 months 4 days

Deferred Financing and Leasin83

Deferred Financing and Leasing Costs (Intangible Amortization Schedule) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Deferred financing and leasing costs, net	$ 159,250	$ 147,038
Leases, Acquired-in-Place, Market Adjustment [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2,018	242
2,019	(265)
2,020	(858)
2,021	(891)
2,022	(762)
Thereafter	(2,637)
Deferred financing and leasing costs, net	(5,171)
Leases, Acquired-in-Place [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2,018	9,748
2,019	6,437
2,020	3,664
2,021	2,839
2,022	2,158
Thereafter	5,551
Deferred financing and leasing costs, net	$ 30,397

Indebtedness (Overview) (Detail

Indebtedness (Overview) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Weighted average interest rate	3.80%	4.30%	4.60%
Interest costs capitalized	$ 21	$ 24.1	$ 16.7
Cash paid for interest	$ 111.8	$ 142.7	$ 149.6

Indebtedness (Amortization and

Indebtedness (Amortization and Maturity Schedule) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
2,017	$ 33,560
2,018	56,547
2,019	420,900
2,020	426,452
2,021	402,172
2,022	302,281
2,023	452,395
2,024	402,503
2,025	404,440
2027 and thereafter	19,800
Subtotal	2,921,050
Reconciling items	(11,505)
Total for consolidated balance sheet	$ 2,909,545
Weighted average interest rate	3.77%
Principal Amortization, Mortgages [Member]
Debt Instrument [Line Items]
2,017	$ 6,565
2,018	6,504
2,019	3,539
2,020	2,504
2,021	2,172
2,022	2,281
2,023	2,395
2,024	2,503
2,025	2,494
2027 and thereafter	19,800
Subtotal	50,757
Reconciling items	4,982
Total for consolidated balance sheet	55,739
Principal Maturities, Mortgages [Member]
Debt Instrument [Line Items]
2,017	26,995
2,018	50,043
2,019	67,361
2,020	65,009
2,021	0
2,022	0
2,023	0
2,024	0
2,025	1,946
2027 and thereafter	0
Subtotal	211,354
Reconciling items	0
Total for consolidated balance sheet	211,354
Unsecured Debt [Member]
Debt Instrument [Line Items]
2,017	0
2,018	0
2,019	350,000
2,020	0
2,021	400,000
2,022	300,000
2,023	450,000
2,024	400,000
2,025	400,000
2027 and thereafter	0
Subtotal	2,300,000
Reconciling items	(16,487)
Total for consolidated balance sheet	2,283,513
Line of Credit [Member]
Debt Instrument [Line Items]
2,017	0
2,018	0
2,019	0
2,020	358,939
2,021	0
2,022	0
2,023	0
2,024	0
2,025	0
2027 and thereafter	0
Subtotal	358,939
Reconciling items	0
Total for consolidated balance sheet	$ 358,939
Due in Next Twelve Months [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.20%
Due in Year Two [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.95%
Due in Year Three [Member]
Debt Instrument [Line Items]
Weighted average interest rate	4.66%
Due in Year Four [Member]
Debt Instrument [Line Items]
Weighted average interest rate	2.62%
Due in Year Five [Member]
Debt Instrument [Line Items]
Weighted average interest rate	4.13%
Due in Year Six [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.39%
Due in Year Seven [Member]
Debt Instrument [Line Items]
Weighted average interest rate	4.40%
Due in Year Eight [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.76%
Due in Year Nine [Member]
Debt Instrument [Line Items]
Weighted average interest rate	3.26%
Due After Year Nine [Member]
Debt Instrument [Line Items]
Weighted average interest rate	4.84%

Indebtedness (Mortgage Loans an

Indebtedness (Mortgage Loans and Unsecured Notes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Aggregate notional amount	$ 96.2	$ 98.9
Mortgages [Member]
Debt Instrument [Line Items]
Maturity date range, start	Jan. 1, 2018
Maturity date range, end	Dec. 31, 2033
Net book value of collateralized real estate properties	$ 491.7
Fixed Rate Debt [Member]
Debt Instrument [Line Items]
Percentage bearing fixed interest, amount	2,562.1
Aggregate notional amount	$ 96.2
Fixed Rate Debt [Member] | Minimum [Member]
Debt Instrument [Line Items]
Effective interest rate	3.00%
Fixed Rate Debt [Member] | Maximum [Member]
Debt Instrument [Line Items]
Effective interest rate	4.84%
Mortgage Loans and Unsecured Notes [Member]
Debt Instrument [Line Items]
Weighted average remaining life	5 years 6 months

Indebtedness (Credit Facility)

Indebtedness (Credit Facility) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)extension	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Amount outstanding	$ 358,939,000	$ 0
Letter of credit obligations	$ 5,100,000
Credit Facility Group Lenders [Member]
Line of Credit Facility [Line Items]
Expiration date	Oct. 20, 2021
Number of maturity extensions | extension	2
Length of maturity extension	6 months
Competitive bid percentage	50.00%
Borrowed funds for covenant ratio	$ 0.60
Covenant ratio	1.50
Debt covenant percentage	60.00%
Line of Credit Facility, Secured Debt to Total Asset Value, Maximum	35.00%
Unencumbered net operating income to unsecured interest expense value for debt covenant	175.00%
Credit Facility Group Lenders [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.875%
Commitment fee percentage	0.15%
Amount outstanding	$ 355,000,000
Maximum borrowing capacity	$ 800,000,000
Credit Facility Group Lenders [Member] | Commercial Paper [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.95%
Amount outstanding	$ 0
Maximum borrowing capacity	100,000,000
Credit Facility Group Lenders [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Letter of credit obligations	$ 5,100,000
Working Capital Facility Lender [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.875%
Commitment fee percentage	0.15%
Expiration date	Oct. 20, 2021
Number of maturity extensions | extension	2
Length of maturity extension	6 months
Amount outstanding	$ 3,900,000
Maximum borrowing capacity	$ 30,000,000

Indebtedness (Activity) (Detail

Indebtedness (Activity) (Details) - USD ($)	1 Months Ended		12 Months Ended
	Nov. 30, 2016	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 30, 2017
Debt Instrument [Line Items]
Debt instrument, face amount			$ 2,921,050,000
Loss on debt extinguishment			49,000	$ 27,099,000	$ 0
Senior Notes [Member] | 3.25% Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate		3.25%
Debt instrument, face amount		$ 400,000,000
Senior Notes [Member] | 5.5% Senior Note [Member]
Debt Instrument [Line Items]
Stated interest rate		5.50%
Repurchased face amount of debt		$ 300,000,000
Loss on debt extinguishment		$ 3,800,000
Senior Notes [Member] | 6.625% Senior Note [Member]
Debt Instrument [Line Items]
Stated interest rate	6.625%
Repurchased face amount of debt	$ 296,500,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			2,300,000,000
Medium-term Notes [Member] | 7.5% Medium Term Note [Member]
Debt Instrument [Line Items]
Stated interest rate	7.50%
Repurchased face amount of debt	$ 100,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Loss on debt extinguishment	$ 23,600,000
Revolving Credit Facility [Member] | Credit Facility Group Lenders [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			800,000,000
Revolving Credit Facility [Member] | Credit Facility Group Lenders [Member] | 2014 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 800,000,000
Revolving Credit Facility [Member] | Credit Facility Group Lenders [Member] | 2017 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						800,000,000
Commercial Paper [Member] | Credit Facility Group Lenders [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			100,000,000
Commercial Paper [Member] | Credit Facility Group Lenders [Member] | 2017 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						100,000,000
Line of Credit [Member] | Working Capital Facility Lender [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 30,000,000
Line of Credit [Member] | Working Capital Facility Lender [Member] | 2017 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 30,000,000

Leasing Activity (Details)

Leasing Activity (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Receivable [Abstract]
2,017	$ 493,131
2,018	462,698
2,019	394,462
2,020	334,969
2,021	273,715
Thereafter	1,102,030
Total	$ 3,061,005

Noncontrolling Interest - Ope90

Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Details) - Series I 2 [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Preferred Units [Line Items]
Amount	$ 7,537
Units (in units)	301,483
Liquidation preference	$ 25
Dividend rate	6.25%
Preferred Units, Total Annual Cash Distributions	$ 472	$ 472	$ 472

Shareholders' Equity - Trust (C

Shareholders' Equity - Trust (Common Shares) (Details)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)shares	Sep. 30, 2017USD ($)shares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Aug. 31, 2015USD ($)
Common Units
Units issued in connection with acquisitions | shares			0	0	0
Continuous Equity Offering
Maximum equity capacity | $	$ 200,000,000		$ 200,000,000
Equity available | $	$ 125,000,000		$ 125,000,000
Shares issued during period under continuous equity offerings, shares, new issues | shares			0	0	0
Share Repurchase
Share repurchase, value | $				$ 40,896,000	$ 71,802,000
Common units [Member]
Common Shares
Common units distributions (USD per share) | $			$ 252,300,000	$ 285,900,000	$ 289,300,000
Ordinary dividend (USD per share) | $ / shares			$ 1.5369	$ 1.0319	$ 1.4348
Qualified dividend (USD per share) | $ / shares			0.0150	0.0013	0
Capital gain - 20% (USD per share) | $ / shares			0.0482	0	0.1112
IRC Sec 1250 unrecapture gain - 25% (USD per share) | $ / shares			0.0749	0.6176	0.3372
Return of capital (USD per share) | $ / shares			0	0.2492	0.0168
Total (USD per share) | $ / shares			$ 1.675	$ 1.90	$ 1.90
Common shares [Member]
Dividend Reinvestment and Share Purchase Plan
Dividend reinvestment plan | shares			42,366	56,426	1,036,437
Share Repurchase
Share repurchase, shares | shares				1,396,844	2,321,794
2015 Share Repurchase Program [Member] | Common shares [Member]
Share Repurchase
Stock repurchase program, authorized amount | $						$ 250,000,000
Share repurchase, shares | shares			0	1,400,000	2,300,000
Share repurchase, value | $				$ 40,900,000	$ 71,800,000
2017 Share Repurchase Program [Member] | Common shares [Member]
Share Repurchase
Stock repurchase program, authorized amount | $		$ 250,000,000
Share repurchase, shares | shares	0
Liberty Property Limited Partnership [Member]
Common Units
Common units outstanding | shares	3,520,205		3,520,205	3,530,031
Closing price of the common shares | $	$ 151,400,000		$ 151,400,000
Units issued in connection with acquisitions | shares			0	0	0
Share Repurchase
Share repurchase, value | $				$ 40,896,000	$ 71,802,000
Liberty Property Limited Partnership [Member] | Common units [Member]
Dividend Reinvestment and Share Purchase Plan
Dividend reinvestment plan | shares			42,366	56,426	1,036,437
Liberty Property Limited Partnership [Member] | 2015 Share Repurchase Program [Member] | Common units [Member]
Share Repurchase
Stock repurchase program, authorized amount | $		$ 250,000,000				$ 250,000,000
Share repurchase, shares | shares		0		1,400,000	2,300,000
Share repurchase, value | $				$ 40,900,000	$ 71,800,000
Liberty Property Limited Partnership [Member] | 2017 Share Repurchase Program [Member] | Common units [Member]
Share Repurchase
Share repurchase, shares | shares	0
Conversion Ratio of Common Units to Common Shares [Member]
Common Units
Common unit, convertible to common stock	1		1
Common stock, converted from common unit	1		1

Owners' Equity - Operating Pa92

Owners' Equity - Operating Partnership Common Units (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2015
Common Shares
Units issued in connection with acquisitions			0	0	0
Share Repurchase
Share repurchase, value				$ 40,896	$ 71,802
Liberty Property Limited Partnership [Member]
Common Shares
Common units outstanding	3,520,205		3,520,205	3,530,031
Closing price of the common shares	$ 151,400		$ 151,400
Units issued in connection with acquisitions			0	0	0
Share Repurchase
Share repurchase, value				$ 40,896	$ 71,802
Liberty Property Limited Partnership [Member] | Common units [Member]
Dividend Reinvestment and Share Purchase Plan
Dividend reinvestment plan			42,366	56,426	1,036,437
Liberty Property Limited Partnership [Member] | 2015 Share Repurchase Program [Member] | Common units [Member]
Share Repurchase
Stock repurchase program, authorized amount		$ 250,000				$ 250,000
Share repurchase, shares		0		1,400,000	2,300,000
Share repurchase, value				$ 40,900	$ 71,800
Liberty Property Limited Partnership [Member] | 2017 Share Repurchase Program [Member] | Common units [Member]
Share Repurchase
Share repurchase, shares	0

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - Pension Plan [Member] - 401(k) [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Plan Disclosure [Line Items]
Company match for defined contribution plan percentage	3.00%
Cost recognized	$ 755	$ 874	$ 1,038

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	21,100,000
Compensation cost capitalized	$ 1,100,000	$ 1,200,000	$ 900,000
Bonus Shares and Plans
Common shares reserved for future issuance	5,049,687	5,264,285	5,574,605
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	750,000
Share-based compensation expense	$ 80,000	$ 122,000	$ 62,000
Bonus Shares and Plans
Maximum percent of salary contributed	10.00%
Discount on market value of shares	15.00%
Shares issued	10,410	11,022	13,127
Stock Options [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option term	10 years
Vesting period	3 years
Share-based compensation expense	$ 73,000	$ 200,000	$ 1,500,000
Weighted average fair value of options granted (USD per share)	$ 0	$ 0	$ 4.11
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0
Exercise price for options outstanding lower limit (USD per share)	$ 20.32
Exercise price for options outstanding upper limit (USD per share)	$ 39.59
Weighted average remaining contractual life of option outstanding	4 years 8 months 28 days
Weighted average remaining contractual life of options exercisable	4 years 5 months 11 days
Total intrinsic value of options exercised	$ 1,400,000	$ 3,500,000	$ 400,000
Number of options outstanding and exercisable that had an exercise price lower than the Company's share price	1,400,000
Aggregate intrinsic value of options	$ 11,400,000
Total cash received from the exercise of options	6,700,000	14,400,000	2,100,000
Unrecognized compensation costs related to nonvested options	$ 0
Stock Options [Member] | First Portion [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	20.00%
Stock Options [Member] | Second Portion [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	50.00%
Stock Options [Member] | Third Portion [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	100.00%
Restricted Stock [Member] | Long Term Incentive Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 11,300,000	$ 12,200,000	$ 10,000,000
Shares granted	310,000
Compensation costs not yet recognized, period for recognition	1 year 12 days
Long Term Incentive Shares
Granted (USD per share)	$ 39.93	$ 32.48	$ 35.14
Total unrecognized compensation cost related to nonvested shares	$ 7,600,000
Total fair value of restricted shares vested	$ 11,700,000	$ 9,000,000	$ 7,400,000
Restricted Stock [Member] | Long Term Incentive Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock [Member] | Long Term Incentive Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock Units (RSUs) [Member] | Second Portion [Member] | 2008 plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years
Bonus Shares [Member] | Bonus Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,000,000	$ 4,700,000	$ 3,900,000
Shares granted	51,416	140,376	111,700
Bonus Shares [Member] | Bonus Shares [Member] | Minimum [Member]
Bonus Shares and Plans
Percent of bonuses taken in cash	100.00%
Bonus Shares [Member] | Bonus Shares [Member] | Maximum [Member]
Bonus Shares and Plans
Percent of bonuses taken in cash	120.00%
Salaries, Wages and Officers' Compensation	$ 50,000
Performance Shares [Member] | Profit Sharing Plan [Member]
Bonus Shares and Plans
Maximum percent of salary contributed	5.00%
Profit sharing plan expense	$ 730,000	$ 669,000	$ 965,000
Chief Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | 2008 plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Chief Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | 2008 plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	272.00%
Chief Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2015 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation		174.00%
Chief Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2014 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation			110.00%
Chief Executive Officer [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2017 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation	132.00%
Executives Other [Member] | Restricted Stock Units (RSUs) [Member] | 2008 plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Executives Other [Member] | Restricted Stock Units (RSUs) [Member] | 2008 plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent	200.00%
Executives Other [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2015 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation		136.00%
Executives Other [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2014 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation			90.00%
Executives Other [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2017 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation	105.00%
Chief Financial Officer [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2008 plan [Member] | 2016 Grant [Member]
Long Term Incentive Shares
Monte Carlo RSU Valuation	160.00%
Chief Financial Officer [Member] | Restricted Stock Units (RSUs) [Member] | First Portion [Member] | 2016 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Chief Financial Officer [Member] | Restricted Stock Units (RSUs) [Member] | Second Portion [Member] | 2017 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Chief Financial Officer [Member] | Restricted Stock Units (RSUs) [Member] | Second Portion [Member] | 2016 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years

Share-Based Compensation (Valua

Share-Based Compensation (Valuation Assumptions) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Options [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate			1.80%
Dividend yield			5.20%
Historical volatility factor			24.00%
Weighted-average expected life			7 years
First Portion [Member] | 2017 Grant [Member] | 2008 plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.43%
Historical volatility factor	20.00%
First Portion [Member] | 2015 Grant [Member] | 2008 plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate		1.01%
Historical volatility factor		19.00%
First Portion [Member] | 2014 Grant [Member] | 2008 plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate			0.99%
Historical volatility factor			17.00%

Share-Based Compensation (Optio

Share-Based Compensation (Option Rollforward) (Details) - Options [Member] - Stock Options [Member] - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of options granted (USD per share)	$ 0	$ 0	$ 4.11
Options
Outstanding January 1, 2016 (in shares)	1,927
Exercised (in shares)	(193)
Forfeited (in shares)	(153)
Outstanding December 31, 2016 (in shares)	1,581	1,927
Exercisable at December 31, 2016 (in shares)	1,417
Weighted Average Exercise Price
Outstanding January 1, 2016 (USD per share)	$ 36.02
Exercised (USD per share)	34.72
Forfeited (USD per share)	48.58
Outstanding December 31, 2016 (USD per share)	34.97	$ 36.02
Exercisable at December 31, 2016 (USD per share)	$ 34.95

Share-Based Compensation (LTI S

Share-Based Compensation (LTI Share Activity) (Details) - Long Term Incentive Shares [Member] - Restricted Stock [Member] - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Nonvested at January 1, 2016 (shares)	812
Granted (shares)	310
Vested (shares)	(330)
Forfeited (shares)	(17)
Nonvested at December 31, 2016 (shares)	775	812
Weighted Avg. Grant Date Fair value
Nonvested at January 1, 2016 (USD per share)	$ 34.71
Granted (USD per share)	39.93	$ 32.48	$ 35.14
Vested (USD per share)	35.57
Forfeited (USD per share)	35.07
Nonvested at December 31, 2016 (USD per share)	$ 36.43	$ 34.71

Commitments and Contingencies98

Commitments and Contingencies (Future Minimum Rental Payments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 1,771
2,019	1,766
2,020	1,766
2,021	1,766
2,022	1,720
2023 though 2067	33,160
Total	41,949
Other Expenses
Operating ground lease expense	$ 102	$ 1,000	$ 815

Commitments and Contingencies99

Commitments and Contingencies (Legal Matters) (Details)	Dec. 31, 2017claim
Loss Contingency, Information about Litigation Matters [Abstract]
Number of legal proceedings	0

Commitments and Contingencie100

Commitments and Contingencies (Other) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²bldg	Dec. 31, 2016USD ($)
Supply Commitment [Line Items]
Letter of credit obligations	$ 5,100
Number of buildings | bldg	37
Development in progress	$ 378,472	$ 267,450
Deferred leasing costs	198,767	$ 179,161
Land Purchases [Member]
Supply Commitment [Line Items]
Remaining amount committed to future land purchases	$ 60,900
Construction in Progress [Member]
Supply Commitment [Line Items]
Number of buildings | bldg	20
Leaseable square feet | ft²	5,600,000
Anticipated aggregate investment	$ 526,700
Deferred leasing costs	13,900
Building and land parcels [Member]
Supply Commitment [Line Items]
Remaining amount committed or obligated to pay for the benefit of current or future tenants	10,500
Tenant Improvements [Member]
Supply Commitment [Line Items]
Maximum tenant improvements not yet completed	18,600
Land and Land Improvements [Member] | Land Purchases [Member]
Supply Commitment [Line Items]
2018 land purchase commitment	32,900
2019 land purchase commitment	$ 28,000
Construction in Progress [Member] | Equity Method Investments [Member] | Construction in Progress [Member]
Supply Commitment [Line Items]
Number of buildings | bldg	3
Anticipated aggregate investment	$ 375,200
Building and Building Improvements [Member] | American Water Works, Inc [Member]
Supply Commitment [Line Items]
Development commitment	176,900
Costs incurred	$ 102,900
Industrial Property [Member] | Building and Building Improvements [Member] | Development commitment [Member]
Supply Commitment [Line Items]
Area of Real Estate Property | ft²	140,000

Quarterly Results of Operati101

Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Operating revenue	$ 192,803	$ 184,511	$ 174,888	$ 167,576	$ 169,733	$ 181,967	$ 178,033	$ 180,965	$ 719,778	$ 710,698	$ 773,960
Net income	$ 131,824	$ 61,159	$ 52,818	$ 44,244	$ 200,291	$ 55,734	$ 51,057	$ 59,063	$ 290,045	$ 366,145	$ 245,924
Net income available to common shareholders - basic (USD per share/unit)	$ 0.87	$ 0.41	$ 0.35	$ 0.29	$ 1.33	$ 0.37	$ 0.34	$ 0.39
Income per common share - diluted (USD per share/unit)	$ 0.87	$ 0.40	$ 0.35	$ 0.29	$ 1.33	$ 0.37	$ 0.34	$ 0.39

Segment Information (Performanc

Segment Information (Performance of the Reportable Segments Based on Property Level Operating Income) (Details) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operating revenue		$ 192,803,000	$ 184,511,000	$ 174,888,000	$ 167,576,000	$ 169,733,000	$ 181,967,000	$ 178,033,000	$ 180,965,000	$ 719,778,000	$ 710,698,000	$ 773,960,000
Development service fee income	[1]									82,673,000	12,941,000	0
Operating Income (Loss)										236,644,000	240,466,000	244,368,000
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense										(88,857,000)	(112,299,000)	(133,557,000)
Loss on debt extinguishment										(49,000)	(27,099,000)	0
Depreciation, Depletion and Amortization, Nonproduction										175,137,000	196,705,000	217,864,000
Impairment - real estate assets (2)										(3,946,000)	(3,879,000)	(17,215,000)
Gain on property dispositions										100,387,000	219,270,000	100,314,000
Equity in earnings of unconsolidated joint ventures										17,155,000	21,970,000	3,149,000
General and administrative expense										(56,975,000)	(67,088,000)	(68,264,000)
Expensed pursuit costs										(5,066,000)	(1,016,000)	(605,000)
Income taxes										(1,992,000)	(1,971,000)	(2,673,000)
Income from continuing operations		$ 114,463,000	$ 63,968,000	$ 50,510,000	$ 42,125,000	$ 197,038,000	$ 51,675,000	$ 48,815,000	$ 56,626,000	271,066,000	354,154,000	235,359,000
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenue										671,280,000	734,050,000	808,683,000
Operating Income (Loss)										448,521,000	468,786,000	504,774,000
Segment Reconciling Items [Member] | Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Operating revenue										(34,035,000)	(36,010,000)	(34,813,000)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenue										(140,000)	(283,000)	90,000
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	[2]									(91,096,000)	(115,077,000)	(135,779,000)
Loss on debt extinguishment											(27,099,000)	0
Depreciation, Depletion and Amortization, Nonproduction	[2],[3]									132,613,000	152,556,000
Depreciation and amortization expense	[2],[3]											(166,500,000)
Impairment - real estate assets (2)	[2]									(10,632,000)	(3,879,000)	(18,244,000)
Gain on property dispositions										100,387,000
Gain on property dispositions											219,270,000	100,314,000
Equity in earnings of unconsolidated joint ventures										17,155,000	21,970,000	3,149,000
General and administrative expense	[2],[3]									(45,191,000)	(44,341,000)	(43,924,000)
Expensed pursuit costs										(5,006,000)	(1,016,000)	(605,000)
Discontinued operations excluding gain on property dispositions										(4,401,000)	(11,991,000)	(10,565,000)
Income taxes	[3]									(240,000)	47,000	(2,351,000)
Other										5,769,000	(40,000)	(5,090,000)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenue										0
North America [Member] | Operating Segments [Member] | Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Operating revenue										74,158,000	66,270,000	71,950,000
Operating Income (Loss)										53,132,000	46,170,000	47,849,000
North America [Member] | Operating Segments [Member] | Chicago Minneapolis [Member]
Segment Reporting Information [Line Items]
Operating revenue										64,706,000	84,028,000	85,363,000
Operating Income (Loss)										39,231,000	45,258,000	44,963,000
North America [Member] | Operating Segments [Member] | Florida [Member]
Segment Reporting Information [Line Items]
Operating revenue										59,526,000	99,733,000	127,184,000
Operating Income (Loss)										39,850,000	62,177,000	77,283,000
North America [Member] | Operating Segments [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Operating revenue										59,957,000	59,582,000	54,031,000
Operating Income (Loss)										32,300,000	32,499,000	31,159,000
North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Operating revenue										163,026,000	141,046,000	133,473,000
Operating Income (Loss)										119,304,000	102,209,000	94,972,000
North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Operating revenue										45,504,000	41,838,000	40,490,000
Operating Income (Loss)										35,279,000	30,862,000	29,679,000
North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Operating revenue										59,762,000	91,656,000	147,712,000
Operating Income (Loss)										35,641,000	53,947,000	80,458,000
North America [Member] | Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating revenue										130,724,000	136,521,000	133,345,000
Operating Income (Loss)										86,127,000	89,274,000	87,925,000
United Kingdom [Member] | Operating Segments [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Operating revenue										13,917,000	13,376,000	15,135,000
Operating Income (Loss)										$ 7,657,000	$ 6,390,000	$ 10,486,000
[1]	(1) Prior to the fourth quarter of 2016, development service fee income had been classified as other income and development service fee expense had been classified as general and administrative expense. See Note 2.
[2]	(2) Includes activity on discontinued operations.
[3]	(3) Excludes costs which are included in determining segment-level net operating income.

Segment Information (Depreciati

Segment Information (Depreciation and amortization of leasing transaction costs) (Details) - Operating Segments [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	$ 49,411	$ 53,273	$ 60,075
United Kingdom [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	339	259	292
North America [Member] | Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	5,061	4,944	5,307
North America [Member] | Chicago Minneapolis [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	4,306	5,858	6,147
North America [Member] | Florida [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	4,084	6,605	9,407
North America [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	5,071	4,713	4,466
North America [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	14,371	12,262	11,641
North America [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	2,754	2,706	2,220
North America [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	3,582	6,134	12,346
North America [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of tenant improvement and lease transaction costs	$ 9,843	$ 9,792	$ 8,249

Segment Information (Operating

Segment Information (Operating Revenues by Segment and Type) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue from External Customer [Line Items]
Operating revenue		$ 192,803	$ 184,511	$ 174,888	$ 167,576	$ 169,733	$ 181,967	$ 178,033	$ 180,965	$ 719,778	$ 710,698	$ 773,960
Development service fee income	[1]									82,673	12,941	0
Operating Segments [Member]
Revenue from External Customer [Line Items]
Operating revenue										671,280	734,050	808,683
Segment Reconciling Items [Member] | Discontinued Operations [Member]
Revenue from External Customer [Line Items]
Operating revenue										(34,035)	(36,010)	(34,813)
Corporate, Non-Segment [Member]
Revenue from External Customer [Line Items]
Operating revenue										(140)	(283)	90
North America [Member] | Operating Segments [Member] | Carolinas Richmond [Member]
Revenue from External Customer [Line Items]
Operating revenue										74,158	66,270	71,950
North America [Member] | Operating Segments [Member] | Chicago Minneapolis [Member]
Revenue from External Customer [Line Items]
Operating revenue										64,706	84,028	85,363
North America [Member] | Operating Segments [Member] | Florida [Member]
Revenue from External Customer [Line Items]
Operating revenue										59,526	99,733	127,184
North America [Member] | Operating Segments [Member] | Houston [Member]
Revenue from External Customer [Line Items]
Operating revenue										59,957	59,582	54,031
North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Revenue from External Customer [Line Items]
Operating revenue										163,026	141,046	133,473
North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Revenue from External Customer [Line Items]
Operating revenue										45,504	41,838	40,490
North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Revenue from External Customer [Line Items]
Operating revenue										59,762	91,656	147,712
North America [Member] | Operating Segments [Member] | Other Segments [Member]
Revenue from External Customer [Line Items]
Operating revenue										130,724	136,521	133,345
United Kingdom [Member] | Operating Segments [Member] | United Kingdom [Member]
Revenue from External Customer [Line Items]
Operating revenue										13,917	13,376	15,135
Industrial Property [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Operating revenue										547,204	529,268	514,896
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Carolinas Richmond [Member]
Revenue from External Customer [Line Items]
Operating revenue										74,158	66,270	62,075
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Chicago Minneapolis [Member]
Revenue from External Customer [Line Items]
Operating revenue										60,826	65,007	62,152
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Florida [Member]
Revenue from External Customer [Line Items]
Operating revenue										56,923	66,028	67,149
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Houston [Member]
Revenue from External Customer [Line Items]
Operating revenue										58,606	58,370	53,802
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Revenue from External Customer [Line Items]
Operating revenue										163,026	138,766	131,168
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Revenue from External Customer [Line Items]
Operating revenue										11,914	12,842	11,809
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Revenue from External Customer [Line Items]
Operating revenue										8,925	19,448	28,457
Industrial Property [Member] | North America [Member] | Operating Segments [Member] | Other Segments [Member]
Revenue from External Customer [Line Items]
Operating revenue										102,457	91,762	86,180
Industrial Property [Member] | United Kingdom [Member] | Operating Segments [Member] | United Kingdom [Member]
Revenue from External Customer [Line Items]
Operating revenue										10,369	10,775	12,104
Office Building [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Operating revenue										124,076	204,782	293,787
Office Building [Member] | North America [Member] | Operating Segments [Member] | Carolinas Richmond [Member]
Revenue from External Customer [Line Items]
Operating revenue										0	0	9,875
Office Building [Member] | North America [Member] | Operating Segments [Member] | Chicago Minneapolis [Member]
Revenue from External Customer [Line Items]
Operating revenue										3,880	19,021	23,211
Office Building [Member] | North America [Member] | Operating Segments [Member] | Florida [Member]
Revenue from External Customer [Line Items]
Operating revenue										2,603	33,705	60,035
Office Building [Member] | North America [Member] | Operating Segments [Member] | Houston [Member]
Revenue from External Customer [Line Items]
Operating revenue										1,351	1,212	229
Office Building [Member] | North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Revenue from External Customer [Line Items]
Operating revenue										0	2,280	2,305
Office Building [Member] | North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Revenue from External Customer [Line Items]
Operating revenue										33,590	28,996	28,681
Office Building [Member] | North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Revenue from External Customer [Line Items]
Operating revenue										50,837	72,208	119,255
Office Building [Member] | North America [Member] | Operating Segments [Member] | Other Segments [Member]
Revenue from External Customer [Line Items]
Operating revenue										28,267	44,759	47,165
Office Building [Member] | United Kingdom [Member] | Operating Segments [Member] | United Kingdom [Member]
Revenue from External Customer [Line Items]
Operating revenue										$ 3,548	$ 2,601	$ 3,031
[1]	(1) Prior to the fourth quarter of 2016, development service fee income had been classified as other income and development service fee expense had been classified as general and administrative expense. See Note 2.

Segment Information (Total Asse

Segment Information (Total Assets by Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 6,439,757	$ 5,992,813
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	6,368,747	5,889,764
Operating Segments [Member] | Carolinas Richmond [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	543,922	503,920
Operating Segments [Member] | Chicago Minneapolis [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	615,186	616,298
Operating Segments [Member] | Florida [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	533,861	514,431
Operating Segments [Member] | Houston [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	498,584	530,438
Operating Segments [Member] | Lehigh Central PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	1,210,746	1,311,815
Operating Segments [Member] | Philadelphia [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	665,843	557,510
Operating Segments [Member] | Southeastern PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	241,128	262,155
Operating Segments [Member] | United Kingdom [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Assets	251,824	189,766
Operating Segments [Member] | Other Segments [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	1,807,653	1,403,431
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Assets	$ 71,010	$ 103,049

Segment Information (Real Estat

Segment Information (Real Estate Assets by Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Real estate assets	$ 5,365,870	$ 5,114,990
North America [Member] | Operating Segments [Member] | Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Real estate assets	491,634	482,736
North America [Member] | Operating Segments [Member] | Chicago Minneapolis [Member]
Segment Reporting Information [Line Items]
Real estate assets	557,776	565,062
North America [Member] | Operating Segments [Member] | Florida [Member]
Segment Reporting Information [Line Items]
Real estate assets	483,315	476,046
North America [Member] | Operating Segments [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Real estate assets	456,591	463,739
North America [Member] | Operating Segments [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Real estate assets	1,118,802	1,234,091
North America [Member] | Operating Segments [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Real estate assets	277,153	332,933
North America [Member] | Operating Segments [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Real estate assets	19,352	123,093
North America [Member] | Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Real estate assets	1,769,705	1,288,208
United Kingdom [Member] | Operating Segments [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Real estate assets	$ 191,542	$ 149,082

Segment Information (Costs Incu

Segment Information (Costs Incurred on Long-lived Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	$ 632,038	$ 503,000	$ 571,583
Operating Segments [Member] | North America [Member] | Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	31,958	51,647	31,175
Operating Segments [Member] | North America [Member] | Chicago Minneapolis [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	14,246	29,317	54,742
Operating Segments [Member] | North America [Member] | Florida [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	23,832	38,312	43,594
Operating Segments [Member] | North America [Member] | Houston [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	17,522	25,831	98,559
Operating Segments [Member] | North America [Member] | Lehigh Central PA [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	89,304	176,386	165,319
Operating Segments [Member] | North America [Member] | Philadelphia [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	30,685	57,691	34,122
Operating Segments [Member] | North America [Member] | Southeastern PA [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	9,737	4,824	5,700
Operating Segments [Member] | North America [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	404,253	107,500	125,412
Operating Segments [Member] | United Kingdom [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Cost incurred on long-lived assets	$ 10,501	$ 11,492	$ 12,960

Accounting for the Impairmen108

Accounting for the Impairment or Disposal of Long-Lived Assets (Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Discontinued Operation
Gain on property dispositions									$ 14,578	$ 0	$ 0
Net income	$ 17,361	$ (2,809)	$ 2,308	$ 2,119	$ 3,253	$ 4,059	$ 2,242	$ 2,437	18,979	11,991	10,565
Discontinued operations net of noncontrolling interest									18,535	11,709	10,319
Discontinued Operations [Member]
Discontinued Operation
Revenues									34,035	36,010	34,813
Operating expenses									(14,014)	(12,989)	(12,309)
Interest and other income									58	133	23
Interest expense									(2,239)	(2,778)	(2,222)
Depreciation and amortization									(6,753)	(8,385)	(8,711)
Impairment charges - real estate assets									(6,686)	0	(1,029)
Net income before property dispositions									4,401	11,991	10,565
Gain on property dispositions									14,578	0	0
Net income									18,979	11,991	10,565
Noncontrolling interest - operating partnership									(444)	(282)	(246)
Discontinued operations net of noncontrolling interest									18,535	11,709	10,319
Capital Expenditure, Discontinued Operations									$ 8,100	$ 1,500	$ 9,900

Accounting for the Impairmen109

Accounting for the Impairment or Disposal of Long-Lived Assets (Significant Sale) (Details) $ in Thousands, ft² in Millions	1 Months Ended	3 Months Ended								12 Months Ended
	Oct. 31, 2016USD ($)ft²aproperties	Dec. 31, 2017USD ($)abldg	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)abldg	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Real Estate [Line Items]
Number of properties | bldg		37								37
Area of land | a		9								9
Net income		$ 131,824	$ 61,159	$ 52,818	$ 44,244	$ 200,291	$ 55,734	$ 51,057	$ 59,063	$ 290,045	$ 366,145	$ 245,924
Noncontrolling interest – operating partnership										(7,224)	(9,070)	(6,192)
Income available to common shareholders										$ 282,340	356,817	239,483
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Real Estate [Line Items]
Number of properties | bldg		8								8
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Real Estate Portfolio [Member]
Real Estate [Line Items]
Number of properties | properties	108
Leaseable square feet | ft²	7.6
Area of land | a	26.7
Proceeds from sale of land	$ 969,000
Gains on sale of land and building	$ 179,100
Net income											48,609	58,792
Noncontrolling interest – operating partnership											(1,142)	(1,370)
Income available to common shareholders											$ 47,467	$ 57,422

Accounting for the Impairmen110

Accounting for the Impairment or Disposal of Long-Lived Assets (Assets Held for Sale) (Details) ft² in Thousands, $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2018USD ($)ft²bldg	Dec. 31, 2017USD ($)abldg	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		37
Area of land | a		9
Gross proceeds		$ 379,139	$ 1,192,918	$ 530,440
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Disposal Group, Including Discontinued Operation, Assets		182,228	164,888
Liabilities held for sale		$ 4,551	8,079
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		27
Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		25
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Disposal Group, Including Discontinued Operations, Land and Land Improvements		$ 25,848	34,406
Disposal Group, Including Discontinued Operations, Building and Improvements		163,195	217,833
Disposal Group, Including Discontinued Operation, Land Available for Development		0	0
Disposal Group, Including Discontinued Operations, Accumulated Depreciation		(98,346)	(106,933)
Disposal Group, Including Discontinued Operation, Intangible Assets		3,502	6,355
Disposal Group, Including Discontinued Operation, Other Assets		7,390	8,679
Disposal Group, Including Discontinued Operation, Assets		101,589	160,340
Liabilities held for sale		$ 3,398	8,079
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		2
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		10
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		2
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Disposal Group, Including Discontinued Operations, Land and Land Improvements		$ 3,476	0
Disposal Group, Including Discontinued Operations, Building and Improvements		80,738	0
Disposal Group, Including Discontinued Operation, Land Available for Development		863	4,548
Disposal Group, Including Discontinued Operations, Accumulated Depreciation		(11,785)	0
Disposal Group, Including Discontinued Operation, Intangible Assets		2,210	0
Disposal Group, Including Discontinued Operation, Other Assets		5,137	0
Disposal Group, Including Discontinued Operation, Assets		80,639	4,548
Liabilities held for sale		$ 1,153	0
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		8
Held for Sale, Includes Disposal Groups and Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		27
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Disposal Group, Including Discontinued Operations, Land and Land Improvements		$ 29,324	34,406
Disposal Group, Including Discontinued Operations, Building and Improvements		243,933	217,833
Disposal Group, Including Discontinued Operation, Land Available for Development		863	4,548
Disposal Group, Including Discontinued Operations, Accumulated Depreciation		(110,131)	(106,933)
Disposal Group, Including Discontinued Operation, Intangible Assets		5,712	6,355
Disposal Group, Including Discontinued Operation, Other Assets		12,527	8,679
Disposal Group, Including Discontinued Operation, Assets		182,228	164,888
Liabilities held for sale		$ 4,551	$ 8,079
Disposed of by Sale, Discontinued Operations and Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		10
Southeastern PA [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		25
Southeastern PA [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		1
Houston [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg		1
Subsequent Event [Member] | Southeastern PA [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | bldg	14
Area of Real Estate Property | ft²	641
Gross proceeds	$ 76,900

Accounting for the Impairmen111

Accounting for the Impairment or Disposal of Long-Lived Assets (Asset Impairments in Reportable Segments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Asset impairment charges	$ 10,632	$ 3,879	$ 18,244
Houston [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	10,632	0	0
Carolinas Richmond [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	0	0	13,755
Minnesota [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	0	3,879	0
Southeastern PA [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	0	0	2,328
Other Segments [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	0	$ 0	2,161
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	6,700		1,000
Land and Land Improvements [Member] | impairment - real estate assets [Member]
Segment Reporting Information [Line Items]
Asset impairment charges	$ 3,900		$ 1,000

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Interest Rate Derivatives
Number of interest rate swaps | contract	3
Aggregate notional amount	$ 96,200	$ 98,900
Termination value of interest rate swap, including accrued interest	2,300
Interest Rate Cash Flow Hedges
Fair value of swaps in other liabilities	2,200	4,900
Amount to be reclassified from accumulated other comprehensive income to increase interest expense over next twelve months	77
Interest Rate Swap [Member] | Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Interest Rate Cash Flow Hedges
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (loss)	176	(648)	$ (1,884)
Interest Rate Swap [Member] | Interest Expense [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Interest Rate Cash Flow Hedges
Amount of loss related to the effective portion reclassified to interest expense	(453)	(1,069)	(1,396)
Amount of gain (loss) related to the ineffective portion recognized in interest expense	$ 168	$ (48)	$ (91)

Supplemental Disclosure to S113

Supplemental Disclosure to Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Significant Noncash Transactions [Line Items]
Write-off of costs related to early debt extinguishment	$ 0	$ 219	$ 0
Unrealized gain (loss) on cash flow hedge	605	410	(488)
Capitalized equity-based compensation	1,096	1,221	876
Redemption of noncontrolling interests - common units	152	132	0
Continuing Operations [Member]
Other Significant Noncash Transactions [Line Items]
Write-off of fully depreciated/amortized property and deferred costs - properties included in continuing operations	16,568	23,331	27,202
Write-off of depreciated property and deferred costs due to sale/demolition - properties included in continuing operations	15,760	461,480	252,017
Changes in accrued development capital expenditures - properties included in continuing operations	12,341	(11,274)	12,935
Discontinued Operations [Member]
Other Significant Noncash Transactions [Line Items]
Write-off of fully depreciated/amortized property and deferred costs - properties included in continuing operations	15,368	18,075	15,137
Write-off of depreciated property and deferred costs due to sale/demolition - properties included in continuing operations	17,335	0	0
Changes in accrued development capital expenditures - properties included in continuing operations	$ 0	$ (94)	$ (971)

Schedule II (Details)

Schedule II (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of the Year	$ 7,332	$ 6,898	$ 7,400
Additions	8,977	5,774	5,479
Deductions	(9,697)	(5,340)	(5,981)
Balance at End of the Year	6,612	7,332	6,898
Allowance for Trade Receivable, Straight Line Rent [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of the Year	530	581	910
Additions	1,729	824	1,233
Deductions	(1,710)	(875)	(1,562)
Balance at End of the Year	549	530	581
Allowance for Trade Receivables [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of the Year	6,802	6,317	6,490
Additions	7,248	4,950	4,246
Deductions	(7,987)	(4,465)	(4,419)
Balance at End of the Year	$ 6,063	$ 6,802	$ 6,317

Schedule III (Details)

Schedule III (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Real Estate and Accumulated Depreciation [Line Items]
Gross Amount Carried at End of Period	$ 5,962,096,000	$ 6,777,467,000	$ 6,846,182,000	$ 6,306,483,000
Accumulated Depreciation	$ 847,106,000	1,062,964,000	1,102,609,000	940,613,000
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,962,096,000	6,777,467,000	6,846,182,000
Real Estate Additions	675,868,000	470,812,000	553,651,000
Real Estate, Cost of Real Estate Sold	(331,481,000)	(1,286,183,000)	(622,366,000)
Real Estate, Gross	6,306,483,000	5,962,096,000	6,777,467,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	847,106,000	1,062,964,000	1,102,609,000
Real Estate Accumulated Depreciation, Depreciation Expense	149,044,000	168,077,000	182,011,000
Real Estate Accumulated Depreciation, Real Estate Sold	(55,537,000)	(383,935,000)	(221,656,000)
Real Estate Accumulated Depreciation	940,613,000	$ 847,106,000	$ 1,062,964,000
Allianz, John Hancock, LaSalle Bank, Athene, New York Life and Wells Fargo [Member] [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				214,200,000
Total Real Estate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				47,946,455
Initial Cost of Land				1,393,447,823
Initial Cost of Buildings				2,336,140,008
Costs Capitalized Subsequent to Acquisition				2,576,894,798
Land and Improvements				1,484,428,501
Building and Improvements				4,822,054,120
Gross Amount Carried at End of Period	6,306,482,621			6,306,482,621
Accumulated Depreciation	940,612,342			940,612,342
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	6,306,482,621
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 940,612,342
Operating Properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carlisle, PA
Encumbrances				0
Initial Cost of Land				4,249,868
Initial Cost of Buildings				13,886,039
Costs Capitalized Subsequent to Acquisition				2,345,375
Land and Improvements				4,095,262
Building and Improvements				16,386,020
Gross Amount Carried at End of Period	$ 20,481,282			20,481,282
Accumulated Depreciation	$ 6,860,959			6,860,959
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,481,282
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,860,959
Operating Properties [Member] | 627 Distribution Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Morrisville, NC
Encumbrances				0
Initial Cost of Land				1,061,370
Initial Cost of Buildings				5,152,110
Costs Capitalized Subsequent to Acquisition				384,204
Land and Improvements				1,061,632
Building and Improvements				5,536,052
Gross Amount Carried at End of Period	$ 6,597,684			6,597,684
Accumulated Depreciation	$ 1,524,610			1,524,610
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,597,684
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,524,610
Operating Properties [Member] | 1775 Hillcrest Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Norcross, GA
Encumbrances				0
Initial Cost of Land				1,318,956
Initial Cost of Buildings				4,379,239
Costs Capitalized Subsequent to Acquisition				351
Land and Improvements				1,318,956
Building and Improvements				4,379,590
Gross Amount Carried at End of Period	$ 5,698,546			5,698,546
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,698,546
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Operating Properties [Member] | 1467 Perryman Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Aberdeen, MD
Encumbrances				0
Initial Cost of Land				12,052,635
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				35,353,684
Land and Improvements				12,334,030
Building and Improvements				35,072,289
Gross Amount Carried at End of Period	$ 47,406,319			47,406,319
Accumulated Depreciation	$ 3,266,781			3,266,781
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 47,406,319
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,266,781
Operating Properties [Member] | 1501 Perryman Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Aberdeen, MD
Encumbrances				0
Initial Cost of Land				5,813,324
Initial Cost of Buildings				18,874,059
Costs Capitalized Subsequent to Acquisition				6,381,862
Land and Improvements				5,816,839
Building and Improvements				25,252,406
Gross Amount Carried at End of Period	$ 31,069,245			31,069,245
Accumulated Depreciation	$ 7,510,366			7,510,366
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 31,069,245
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 7,510,366
Operating Properties [Member] | 869 S Route 53 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Addison, IL
Encumbrances				0
Initial Cost of Land				1,194,223
Initial Cost of Buildings				4,201,881
Costs Capitalized Subsequent to Acquisition				85,733
Land and Improvements				1,194,223
Building and Improvements				4,287,615
Gross Amount Carried at End of Period	$ 5,481,838			5,481,838
Accumulated Depreciation	$ 553,871			553,871
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,481,838
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 553,871
Operating Properties [Member] | 901 S Route 53 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Addison, IL
Encumbrances				0
Initial Cost of Land				2,055,066
Initial Cost of Buildings				5,984,093
Costs Capitalized Subsequent to Acquisition				880,440
Land and Improvements				2,055,066
Building and Improvements				6,864,533
Gross Amount Carried at End of Period	$ 8,919,599			8,919,599
Accumulated Depreciation	$ 964,359			964,359
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,919,599
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 964,359
Operating Properties [Member] | 8620 Congdon Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Alburtis, PA
Encumbrances				0
Initial Cost of Land				38,328,000
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				36,639,297
Land and Improvements				38,328,000
Building and Improvements				36,639,297
Gross Amount Carried at End of Period	$ 74,967,297			74,967,297
Accumulated Depreciation	$ 1,625,979			1,625,979
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 74,967,297
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,625,979
Operating Properties [Member] | 200 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				4,722,683
Initial Cost of Buildings				18,922,645
Costs Capitalized Subsequent to Acquisition				967,059
Land and Improvements				4,722,683
Building and Improvements				19,889,704
Gross Amount Carried at End of Period	$ 24,612,387			24,612,387
Accumulated Depreciation	$ 6,690,719			6,690,719
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 24,612,387
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,690,719
Operating Properties [Member] | 250 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				3,599,936
Initial Cost of Buildings				12,099,145
Costs Capitalized Subsequent to Acquisition				2,200,244
Land and Improvements				3,717,733
Building and Improvements				14,181,592
Gross Amount Carried at End of Period	$ 17,899,325			17,899,325
Accumulated Depreciation	$ 5,557,571			5,557,571
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 17,899,325
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 5,557,571
Operating Properties [Member] | 400 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				8,065,500
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				29,708,283
Land and Improvements				8,184,096
Building and Improvements				29,589,687
Gross Amount Carried at End of Period	$ 37,773,783			37,773,783
Accumulated Depreciation	$ 15,721,633			15,721,633
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 37,773,783
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 15,721,633
Operating Properties [Member] | 650 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				5,208,248
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				32,432,054
Land and Improvements				9,961,788
Building and Improvements				27,678,514
Gross Amount Carried at End of Period	$ 37,640,302			37,640,302
Accumulated Depreciation	$ 10,591,886			10,591,886
Date of Construction or Acquisition	2,002
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 37,640,302
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 10,591,886
Operating Properties [Member] | 651 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				4,308,646
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				17,846,386
Land and Improvements				4,308,646
Building and Improvements				17,846,386
Gross Amount Carried at End of Period	$ 22,155,032			22,155,032
Accumulated Depreciation	$ 9,669,809			9,669,809
Date of Construction or Acquisition	2,000
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 22,155,032
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 9,669,809
Operating Properties [Member] | 700 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				3,473,120
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				20,307,750
Land and Improvements				4,174,970
Building and Improvements				19,605,900
Gross Amount Carried at End of Period	$ 23,780,870			23,780,870
Accumulated Depreciation	$ 11,018,939			11,018,939
Date of Construction or Acquisition	1,998
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 23,780,870
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 11,018,939
Operating Properties [Member] | 705 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				10,594,027
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				28,815,711
Land and Improvements				10,596,767
Building and Improvements				28,812,971
Gross Amount Carried at End of Period	$ 39,409,738			39,409,738
Accumulated Depreciation	$ 15,981,798			15,981,798
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 39,409,738
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 15,981,798
Operating Properties [Member] | 7165 Ambassador Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				792,999
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,694,984
Land and Improvements				804,848
Building and Improvements				4,683,135
Gross Amount Carried at End of Period	$ 5,487,983			5,487,983
Accumulated Depreciation	$ 2,146,445			2,146,445
Date of Construction or Acquisition	2,002
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,487,983
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,146,445
Operating Properties [Member] | 7248 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				2,670,849
Initial Cost of Buildings				13,307,408
Costs Capitalized Subsequent to Acquisition				4,629,975
Land and Improvements				2,670,673
Building and Improvements				17,937,559
Gross Amount Carried at End of Period	$ 20,608,232			20,608,232
Accumulated Depreciation	$ 9,398,129			9,398,129
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,608,232
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 9,398,129
Operating Properties [Member] | 7339 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				1,187,776
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,592,938
Land and Improvements				1,197,447
Building and Improvements				7,583,267
Gross Amount Carried at End of Period	$ 8,780,714			8,780,714
Accumulated Depreciation	$ 4,174,870			4,174,870
Date of Construction or Acquisition	1,996
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,780,714
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,174,870
Operating Properties [Member] | 7437 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				717,488
Initial Cost of Buildings				5,022,413
Costs Capitalized Subsequent to Acquisition				3,450,291
Land and Improvements				726,651
Building and Improvements				8,463,540
Gross Amount Carried at End of Period	$ 9,190,191			9,190,191
Accumulated Depreciation	$ 5,460,929			5,460,929
Date of Construction or Acquisition	1,976
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,190,191
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 5,460,929
Operating Properties [Member] | 8014 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				4,019,258
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				11,192,116
Land and Improvements				3,645,117
Building and Improvements				11,566,257
Gross Amount Carried at End of Period	$ 15,211,374			15,211,374
Accumulated Depreciation	$ 5,409,248			5,409,248
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,211,374
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 5,409,248
Operating Properties [Member] | 8150 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				2,564,167
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,480,757
Land and Improvements				2,571,466
Building and Improvements				9,473,458
Gross Amount Carried at End of Period	$ 12,044,924			12,044,924
Accumulated Depreciation	$ 3,917,347			3,917,347
Date of Construction or Acquisition	2,002
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,044,924
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,917,347
Operating Properties [Member] | 8250 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				1,025,667
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,255,168
Land and Improvements				1,035,854
Building and Improvements				5,244,981
Gross Amount Carried at End of Period	$ 6,280,835			6,280,835
Accumulated Depreciation	$ 1,966,477			1,966,477
Date of Construction or Acquisition	2,002
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,280,835
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,966,477
Operating Properties [Member] | 8400 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				6,725,948
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				27,404,693
Land and Improvements				7,521,211
Building and Improvements				26,609,430
Gross Amount Carried at End of Period	$ 34,130,641			34,130,641
Accumulated Depreciation	$ 8,076,494			8,076,494
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 34,130,641
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 8,076,494
Operating Properties [Member] | 6330 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				531,268
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,075,126
Land and Improvements				532,047
Building and Improvements				6,074,347
Gross Amount Carried at End of Period	$ 6,606,394			6,606,394
Accumulated Depreciation	$ 4,051,848			4,051,848
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,606,394
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,051,848
Operating Properties [Member] | 6350 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				360,027
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,526,417
Land and Improvements				560,691
Building and Improvements				4,325,753
Gross Amount Carried at End of Period	$ 4,886,444			4,886,444
Accumulated Depreciation	$ 2,607,549			2,607,549
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,886,444
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,607,549
Operating Properties [Member] | 6370 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				540,795
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,121,409
Land and Improvements				541,459
Building and Improvements				4,120,745
Gross Amount Carried at End of Period	$ 4,662,204			4,662,204
Accumulated Depreciation	$ 2,579,828			2,579,828
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,662,204
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,579,828
Operating Properties [Member] | 6390 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				707,203
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,372,168
Land and Improvements				707,867
Building and Improvements				3,371,504
Gross Amount Carried at End of Period	$ 4,079,371			4,079,371
Accumulated Depreciation	$ 1,929,807			1,929,807
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,079,371
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,929,807
Operating Properties [Member] | 6520 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				453,315
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,571,738
Land and Improvements				484,361
Building and Improvements				1,540,692
Gross Amount Carried at End of Period	$ 2,025,053			2,025,053
Accumulated Depreciation	$ 713,180			713,180
Date of Construction or Acquisition	1,996
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,025,053
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 713,180
Operating Properties [Member] | 6540 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				422,042
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,337,554
Land and Improvements				422,730
Building and Improvements				5,336,866
Gross Amount Carried at End of Period	$ 5,759,596			5,759,596
Accumulated Depreciation	$ 3,119,448			3,119,448
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,759,596
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,119,448
Operating Properties [Member] | 6560 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				458,281
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,856,829
Land and Improvements				458,945
Building and Improvements				3,856,165
Gross Amount Carried at End of Period	$ 4,315,110			4,315,110
Accumulated Depreciation	$ 2,331,497			2,331,497
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,315,110
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,331,497
Operating Properties [Member] | 6580 Snowdrift Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				388,328
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,877,166
Land and Improvements				389,081
Building and Improvements				4,876,413
Gross Amount Carried at End of Period	$ 5,265,494			5,265,494
Accumulated Depreciation	$ 3,220,831			3,220,831
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,265,494
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,220,831
Operating Properties [Member] | 7620 Cetronia Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				1,091,806
Initial Cost of Buildings				3,851,456
Costs Capitalized Subsequent to Acquisition				446,341
Land and Improvements				1,093,724
Building and Improvements				4,295,879
Gross Amount Carried at End of Period	$ 5,389,603			5,389,603
Accumulated Depreciation	$ 2,379,820			2,379,820
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,389,603
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,379,820
Operating Properties [Member] | 11222 Melrose Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Franklin Park, IL
Encumbrances				0
Initial Cost of Land				2,999,106
Initial Cost of Buildings				4,658,605
Costs Capitalized Subsequent to Acquisition				104,074
Land and Improvements				2,999,106
Building and Improvements				4,762,679
Gross Amount Carried at End of Period	$ 7,761,785			7,761,785
Accumulated Depreciation	$ 292,028			292,028
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,761,785
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 292,028
Operating Properties [Member] | 3095 Presidential Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Atlanta, GA
Encumbrances				0
Initial Cost of Land				200,351
Initial Cost of Buildings				1,729,161
Costs Capitalized Subsequent to Acquisition				254,912
Land and Improvements				200,351
Building and Improvements				1,984,073
Gross Amount Carried at End of Period	$ 2,184,424			2,184,424
Accumulated Depreciation	$ 342,828			342,828
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,184,424
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 342,828
Operating Properties [Member] | 3097 Presidential Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Atlanta, GA
Encumbrances				0
Initial Cost of Land				188,680
Initial Cost of Buildings				1,721,048
Costs Capitalized Subsequent to Acquisition				377,679
Land and Improvements				188,680
Building and Improvements				2,098,727
Gross Amount Carried at End of Period	$ 2,287,407			2,287,407
Accumulated Depreciation	$ 252,522			252,522
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,287,407
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 252,522
Operating Properties [Member] | 7030 Buford Highway NE [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Atlanta, GA
Encumbrances				0
Initial Cost of Land				919,850
Initial Cost of Buildings				4,051,340
Costs Capitalized Subsequent to Acquisition				938,092
Land and Improvements				919,850
Building and Improvements				4,989,432
Gross Amount Carried at End of Period	$ 5,909,282			5,909,282
Accumulated Depreciation	$ 864,963			864,963
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,909,282
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 864,963
Operating Properties [Member] | Barton 150 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Barton Under Needwood, UK
Encumbrances				0
Initial Cost of Land				2,196,955
Initial Cost of Buildings				13,643,981
Costs Capitalized Subsequent to Acquisition				(2,911,461)
Land and Improvements				1,793,045
Building and Improvements				11,136,430
Gross Amount Carried at End of Period	$ 12,929,475			12,929,475
Accumulated Depreciation	$ 1,423,910			1,423,910
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,929,475
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,423,910
Operating Properties [Member] | 1055-1071 Kingsland Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Batavia, IL
Encumbrances				0
Initial Cost of Land				727,294
Initial Cost of Buildings				2,367,529
Costs Capitalized Subsequent to Acquisition				686,813
Land and Improvements				727,294
Building and Improvements				3,054,342
Gross Amount Carried at End of Period	$ 3,781,636			3,781,636
Accumulated Depreciation	$ 517,875			517,875
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,781,636
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 517,875
Operating Properties [Member] | 4606 Richlynn Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Belcamp, MD
Encumbrances				0
Initial Cost of Land				299,600
Initial Cost of Buildings				1,818,861
Costs Capitalized Subsequent to Acquisition				722,992
Land and Improvements				299,600
Building and Improvements				2,541,853
Gross Amount Carried at End of Period	$ 2,841,453			2,841,453
Accumulated Depreciation	$ 1,167,850			1,167,850
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,841,453
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,167,850
Operating Properties [Member] | 11800 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville,MD
Encumbrances				0
Initial Cost of Land				2,769,962
Initial Cost of Buildings				1,829,028
Costs Capitalized Subsequent to Acquisition				257,575
Land and Improvements				2,663,725
Building and Improvements				2,192,841
Gross Amount Carried at End of Period	$ 4,856,566			4,856,566
Accumulated Depreciation	$ 392,541			392,541
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,856,566
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 392,541
Operating Properties [Member] | 11850 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville,MD
Encumbrances				0
Initial Cost of Land				3,595,044
Initial Cost of Buildings				2,415,132
Costs Capitalized Subsequent to Acquisition				164,695
Land and Improvements				3,457,162
Building and Improvements				2,717,709
Gross Amount Carried at End of Period	$ 6,174,871			6,174,871
Accumulated Depreciation	$ 621,879			621,879
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,174,871
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 621,879
Operating Properties [Member] | 11900 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville,MD
Encumbrances				0
Initial Cost of Land				3,492,036
Initial Cost of Buildings				2,024,038
Costs Capitalized Subsequent to Acquisition				521,421
Land and Improvements				3,358,104
Building and Improvements				2,679,391
Gross Amount Carried at End of Period	$ 6,037,495			6,037,495
Accumulated Depreciation	$ 673,883			673,883
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,037,495
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 673,883
Operating Properties [Member] | 16420 West Hardy Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				529,876
Initial Cost of Buildings				3,267,872
Costs Capitalized Subsequent to Acquisition				405,454
Land and Improvements				529,876
Building and Improvements				3,673,326
Gross Amount Carried at End of Period	$ 4,203,202			4,203,202
Accumulated Depreciation	$ 603,596			603,596
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,203,202
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 603,596
Operating Properties [Member] | 12104 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville,MD
Encumbrances				0
Initial Cost of Land				2,021,752
Initial Cost of Buildings				2,503,802
Costs Capitalized Subsequent to Acquisition				301,581
Land and Improvements				2,021,752
Building and Improvements				2,805,383
Gross Amount Carried at End of Period	$ 4,827,135			4,827,135
Accumulated Depreciation	$ 632,738			632,738
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,827,135
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 632,738
Operating Properties [Member] | 12200 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville,MD
Encumbrances				0
Initial Cost of Land				1,347,882
Initial Cost of Buildings				1,460,291
Costs Capitalized Subsequent to Acquisition				624,034
Land and Improvements				1,347,882
Building and Improvements				2,084,325
Gross Amount Carried at End of Period	$ 3,432,207			3,432,207
Accumulated Depreciation	$ 374,847			374,847
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,432,207
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 374,847
Operating Properties [Member] | 12240 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Beltsville,MD
Encumbrances				0
Initial Cost of Land				1,479,307
Initial Cost of Buildings				2,159,997
Costs Capitalized Subsequent to Acquisition				791,326
Land and Improvements				1,479,307
Building and Improvements				2,951,324
Gross Amount Carried at End of Period	$ 4,430,631			4,430,631
Accumulated Depreciation	$ 491,902			491,902
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,430,631
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 491,902
Operating Properties [Member] | 1071 Thorndale Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bensenville,IL
Encumbrances				0
Initial Cost of Land				2,173,006
Initial Cost of Buildings				2,280,788
Costs Capitalized Subsequent to Acquisition				279,995
Land and Improvements				2,016,715
Building and Improvements				2,717,074
Gross Amount Carried at End of Period	$ 4,733,789			4,733,789
Accumulated Depreciation	$ 487,001			487,001
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,733,789
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 487,001
Operating Properties [Member] | 1260-1274 Ellis Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bensenville,IL
Encumbrances				0
Initial Cost of Land				2,298,560
Initial Cost of Buildings				4,020,382
Costs Capitalized Subsequent to Acquisition				360,477
Land and Improvements				2,298,560
Building and Improvements				4,380,859
Gross Amount Carried at End of Period	$ 6,679,419			6,679,419
Accumulated Depreciation	$ 753,050			753,050
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,679,419
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 753,050
Operating Properties [Member] | 371-377 Meyer Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bensenville,IL
Encumbrances				0
Initial Cost of Land				1,903,423
Initial Cost of Buildings				3,563,953
Costs Capitalized Subsequent to Acquisition				581,985
Land and Improvements				1,903,423
Building and Improvements				4,145,938
Gross Amount Carried at End of Period	$ 6,049,361			6,049,361
Accumulated Depreciation	$ 646,670			646,670
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,049,361
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 646,670
Operating Properties [Member] | 850-880 Devon Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bensenville,IL
Encumbrances				0
Initial Cost of Land				2,958,756
Initial Cost of Buildings				7,959,013
Costs Capitalized Subsequent to Acquisition				780,767
Land and Improvements				2,958,756
Building and Improvements				8,739,780
Gross Amount Carried at End of Period	$ 11,698,536			11,698,536
Accumulated Depreciation	$ 1,397,398			1,397,398
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,698,536
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,397,398
Operating Properties [Member] | 10 Emery Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bethlehem, PA
Encumbrances				0
Initial Cost of Land				5,591,216
Initial Cost of Buildings				32,941,818
Costs Capitalized Subsequent to Acquisition				8,086,723
Land and Improvements				8,947,574
Building and Improvements				37,672,183
Gross Amount Carried at End of Period	$ 46,619,757			46,619,757
Accumulated Depreciation	$ 4,444,772			4,444,772
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 46,619,757
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,444,772
Operating Properties [Member] | 2785 Commerce Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bethlehem, PA
Encumbrances				0
Initial Cost of Land				11,961,623
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				46,710,814
Land and Improvements				12,009,985
Building and Improvements				46,662,452
Gross Amount Carried at End of Period	$ 58,672,437			58,672,437
Accumulated Depreciation	$ 5,682,988			5,682,988
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 58,672,437
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 5,682,988
Operating Properties [Member] | 1455 Remington Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bolingbrook, IL
Encumbrances				0
Initial Cost of Land				2,501,294
Initial Cost of Buildings				10,704,719
Costs Capitalized Subsequent to Acquisition				2,027
Land and Improvements				2,501,294
Building and Improvements				10,706,746
Gross Amount Carried at End of Period	$ 13,208,040			13,208,040
Accumulated Depreciation	$ 1,443,812			1,443,812
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,208,040
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,443,812
Operating Properties [Member] | 150 E Crossroads Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bolingbrook, IL
Encumbrances				0
Initial Cost of Land				3,078,949
Initial Cost of Buildings				14,143,377
Costs Capitalized Subsequent to Acquisition				1,304,570
Land and Improvements				3,078,949
Building and Improvements				15,447,947
Gross Amount Carried at End of Period	$ 18,526,896			18,526,896
Accumulated Depreciation	$ 2,279,751			2,279,751
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 18,526,896
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,279,751
Operating Properties [Member] | 553 S Joliet Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bolingbrook, IL
Encumbrances				0
Initial Cost of Land				3,764,831
Initial Cost of Buildings				15,109,947
Costs Capitalized Subsequent to Acquisition				2,608,351
Land and Improvements				3,764,831
Building and Improvements				17,718,298
Gross Amount Carried at End of Period	$ 21,483,129			21,483,129
Accumulated Depreciation	$ 2,927,857			2,927,857
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,483,129
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,927,857
Operating Properties [Member] | 400 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Breinigsville, PA
Encumbrances				0
Initial Cost of Land				2,859,106
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				12,523,348
Land and Improvements				2,865,575
Building and Improvements				12,516,879
Gross Amount Carried at End of Period	$ 15,382,454			15,382,454
Accumulated Depreciation	$ 3,591,183			3,591,183
Date of Construction or Acquisition	2,003
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,382,454
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,591,183
Operating Properties [Member] | 8201 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Breinigsville, PA
Encumbrances				0
Initial Cost of Land				2,089,719
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,254,674
Land and Improvements				2,222,168
Building and Improvements				9,122,225
Gross Amount Carried at End of Period	$ 11,344,393			11,344,393
Accumulated Depreciation	$ 2,117,229			2,117,229
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,344,393
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,117,229
Operating Properties [Member] | 8451 Willard Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Breinigsville, PA
Encumbrances				0
Initial Cost of Land				8,752,708
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				40,892,454
Land and Improvements				11,511,499
Building and Improvements				38,133,663
Gross Amount Carried at End of Period	$ 49,645,162			49,645,162
Accumulated Depreciation	$ 11,459,148			11,459,148
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 49,645,162
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 11,459,148
Operating Properties [Member] | 860 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Breinigsville, PA
Encumbrances				0
Initial Cost of Land				8,118,881
Initial Cost of Buildings				18,885,486
Costs Capitalized Subsequent to Acquisition				7,523,072
Land and Improvements				8,118,881
Building and Improvements				26,408,558
Gross Amount Carried at End of Period	$ 34,527,439			34,527,439
Accumulated Depreciation	$ 10,705,203			10,705,203
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 34,527,439
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 10,705,203
Operating Properties [Member] | 3525 Gravel Springs Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Buford, GA
Encumbrances				0
Initial Cost of Land				1,391,065
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,767,546
Land and Improvements				1,629,677
Building and Improvements				5,528,934
Gross Amount Carried at End of Period	$ 7,158,611			7,158,611
Accumulated Depreciation	$ 81,499			81,499
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,158,611
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 81,499
Operating Properties [Member] | 40 Logistics Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carlisle, PA
Encumbrances				0
Initial Cost of Land				7,981,850
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				33,019,624
Land and Improvements				8,081,272
Building and Improvements				32,920,202
Gross Amount Carried at End of Period	$ 41,001,474			41,001,474
Accumulated Depreciation	$ 5,205,564			5,205,564
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 41,001,474
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 5,205,564
Operating Properties [Member] | 135-195 East Elk Trail [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carol Stream, IL
Encumbrances				0
Initial Cost of Land				4,873,094
Initial Cost of Buildings				12,430,320
Costs Capitalized Subsequent to Acquisition				2,711,700
Land and Improvements				4,873,094
Building and Improvements				15,142,020
Gross Amount Carried at End of Period	$ 20,015,114			20,015,114
Accumulated Depreciation	$ 1,653,950			1,653,950
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,015,114
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,653,950
Operating Properties [Member] | 515 Kehoe Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carol Stream, IL
Encumbrances				0
Initial Cost of Land				5,523,427
Initial Cost of Buildings				14,581,705
Costs Capitalized Subsequent to Acquisition				1,018,131
Land and Improvements				5,523,427
Building and Improvements				15,599,836
Gross Amount Carried at End of Period	$ 21,123,263			21,123,263
Accumulated Depreciation	$ 1,794,650			1,794,650
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,123,263
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,794,650
Operating Properties [Member] | 1413 Bradley Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carrollton, TX
Encumbrances				0
Initial Cost of Land				247,477
Initial Cost of Buildings				2,028,322
Costs Capitalized Subsequent to Acquisition				83,692
Land and Improvements				247,477
Building and Improvements				2,112,014
Gross Amount Carried at End of Period	$ 2,359,491			2,359,491
Accumulated Depreciation	$ 335,971			335,971
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,359,491
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 335,971
Operating Properties [Member] | 3200 Belmeade Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carrollton, TX
Encumbrances				0
Initial Cost of Land				1,042,453
Initial Cost of Buildings				8,027,974
Costs Capitalized Subsequent to Acquisition				545,748
Land and Improvements				1,042,453
Building and Improvements				8,573,722
Gross Amount Carried at End of Period	$ 9,616,175			9,616,175
Accumulated Depreciation	$ 1,203,243			1,203,243
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,616,175
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,203,243
Operating Properties [Member] | 16325 S Avalon Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carson, CA
Encumbrances				0
Initial Cost of Land				26,432,369
Initial Cost of Buildings				19,669,675
Costs Capitalized Subsequent to Acquisition				288,256
Land and Improvements				26,432,369
Building and Improvements				19,957,931
Gross Amount Carried at End of Period	$ 46,390,300			46,390,300
Accumulated Depreciation	$ 90,391			90,391
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 46,390,300
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 90,391
Operating Properties [Member] | 1475 Nitterhouse Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chambersburg, PA
Encumbrances				0
Initial Cost of Land				7,081,007
Initial Cost of Buildings				39,002,011
Costs Capitalized Subsequent to Acquisition				2,094,847
Land and Improvements				7,081,007
Building and Improvements				41,096,858
Gross Amount Carried at End of Period	$ 48,177,865			48,177,865
Accumulated Depreciation	$ 6,065,304			6,065,304
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 48,177,865
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,065,304
Operating Properties [Member] | 95 Kriner Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chambersburg, PA
Encumbrances				0
Initial Cost of Land				8,695,501
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				35,060,794
Land and Improvements				9,407,871
Building and Improvements				34,348,424
Gross Amount Carried at End of Period	$ 43,756,295			43,756,295
Accumulated Depreciation	$ 9,231,761			9,231,761
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 43,756,295
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 9,231,761
Operating Properties [Member] | 9000 109th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Champlin, MN
Encumbrances				0
Initial Cost of Land				1,251,043
Initial Cost of Buildings				11,662,995
Costs Capitalized Subsequent to Acquisition				120,863
Land and Improvements				1,251,043
Building and Improvements				11,783,858
Gross Amount Carried at End of Period	$ 13,034,901			13,034,901
Accumulated Depreciation	$ 2,132,475			2,132,475
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,034,901
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,132,475
Operating Properties [Member] | 11701 Goodrich Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				2,054,621
Initial Cost of Buildings				6,356,151
Costs Capitalized Subsequent to Acquisition				630,877
Land and Improvements				2,054,621
Building and Improvements				6,987,027
Gross Amount Carried at End of Period	$ 9,041,648			9,041,648
Accumulated Depreciation	$ 1,347,806			1,347,806
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,041,648
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,347,806
Operating Properties [Member] | 12810 Virkler Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				475,368
Initial Cost of Buildings				2,367,586
Costs Capitalized Subsequent to Acquisition				882,005
Land and Improvements				476,262
Building and Improvements				3,248,696
Gross Amount Carried at End of Period	$ 3,724,958			3,724,958
Accumulated Depreciation	$ 563,666			563,666
Date of Construction or Acquisition	2,010
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,724,958
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 563,666
Operating Properties [Member] | 2700 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				912,500
Initial Cost of Buildings				4,721,259
Costs Capitalized Subsequent to Acquisition				346,813
Land and Improvements				912,500
Building and Improvements				5,068,072
Gross Amount Carried at End of Period	$ 5,980,572			5,980,572
Accumulated Depreciation	$ 917,487			917,487
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,980,572
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 917,487
Operating Properties [Member] | 2701 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,275,000
Initial Cost of Buildings				4,649,750
Costs Capitalized Subsequent to Acquisition				646,264
Land and Improvements				1,275,000
Building and Improvements				5,296,014
Gross Amount Carried at End of Period	$ 6,571,014			6,571,014
Accumulated Depreciation	$ 985,434			985,434
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,571,014
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 985,434
Operating Properties [Member] | 2730 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,878,750
Initial Cost of Buildings				10,129,499
Costs Capitalized Subsequent to Acquisition				33,298
Land and Improvements				1,878,750
Building and Improvements				10,162,797
Gross Amount Carried at End of Period	$ 12,041,547			12,041,547
Accumulated Depreciation	$ 1,712,638			1,712,638
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,041,547
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,712,638
Operating Properties [Member] | 2801 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,065,000
Initial Cost of Buildings				6,975,250
Costs Capitalized Subsequent to Acquisition				650,916
Land and Improvements				1,065,000
Building and Improvements				7,626,166
Gross Amount Carried at End of Period	$ 8,691,166			8,691,166
Accumulated Depreciation	$ 1,243,976			1,243,976
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,691,166
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,243,976
Operating Properties [Member] | 3000 Crosspoint Center Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,831,250
Initial Cost of Buildings				10,779,412
Costs Capitalized Subsequent to Acquisition				1,101,098
Land and Improvements				1,831,250
Building and Improvements				11,880,510
Gross Amount Carried at End of Period	$ 13,711,760			13,711,760
Accumulated Depreciation	$ 2,074,452			2,074,452
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,711,760
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,074,452
Operating Properties [Member] | 3005 Crosspoint Center Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,990,000
Initial Cost of Buildings				6,561,540
Costs Capitalized Subsequent to Acquisition				1,169,814
Land and Improvements				1,990,000
Building and Improvements				7,731,354
Gross Amount Carried at End of Period	$ 9,721,354			9,721,354
Accumulated Depreciation	$ 1,329,779			1,329,779
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,721,354
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,329,779
Operating Properties [Member] | 4045 Perimeter West Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,418,928
Initial Cost of Buildings				7,511,050
Costs Capitalized Subsequent to Acquisition				632,664
Land and Improvements				1,418,928
Building and Improvements				8,143,714
Gross Amount Carried at End of Period	$ 9,562,642			9,562,642
Accumulated Depreciation	$ 1,414,308			1,414,308
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,562,642
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,414,308
Operating Properties [Member] | 4047 Perimeter West Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,279,004
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,399,609
Land and Improvements				1,279,004
Building and Improvements				6,399,609
Gross Amount Carried at End of Period	$ 7,678,613			7,678,613
Accumulated Depreciation	$ 1,083,916			1,083,916
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,678,613
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,083,916
Operating Properties [Member] | 4525 Statesville Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				841,250
Initial Cost of Buildings				5,279,315
Costs Capitalized Subsequent to Acquisition				317,199
Land and Improvements				837,144
Building and Improvements				5,600,620
Gross Amount Carried at End of Period	$ 6,437,764			6,437,764
Accumulated Depreciation	$ 958,955			958,955
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,437,764
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 958,955
Operating Properties [Member] | 4835 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				3,315,149
Initial Cost of Land				690,750
Initial Cost of Buildings				5,086,388
Costs Capitalized Subsequent to Acquisition				133,402
Land and Improvements				690,750
Building and Improvements				5,219,790
Gross Amount Carried at End of Period	$ 5,910,540			5,910,540
Accumulated Depreciation	$ 763,314			763,314
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,910,540
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 763,314
Operating Properties [Member] | 4925 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				3,339,557
Initial Cost of Land				603,003
Initial Cost of Buildings				4,969,011
Costs Capitalized Subsequent to Acquisition				147,245
Land and Improvements				603,003
Building and Improvements				5,116,256
Gross Amount Carried at End of Period	$ 5,719,259			5,719,259
Accumulated Depreciation	$ 829,242			829,242
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,719,259
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 829,242
Operating Properties [Member] | 5032 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,416,763
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,031,057
Land and Improvements				1,416,763
Building and Improvements				9,031,057
Gross Amount Carried at End of Period	$ 10,447,820			10,447,820
Accumulated Depreciation	$ 469,576			469,576
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,447,820
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 469,576
Operating Properties [Member] | 5033 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				2,845,006
Initial Cost of Land				509,247
Initial Cost of Buildings				4,710,218
Costs Capitalized Subsequent to Acquisition				183,930
Land and Improvements				613,962
Building and Improvements				4,789,433
Gross Amount Carried at End of Period	$ 5,403,395			5,403,395
Accumulated Depreciation	$ 756,635			756,635
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,403,395
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 756,635
Operating Properties [Member] | 5039 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				1,027,500
Initial Cost of Buildings				6,172,807
Costs Capitalized Subsequent to Acquisition				63,150
Land and Improvements				1,027,500
Building and Improvements				6,235,957
Gross Amount Carried at End of Period	$ 7,263,457			7,263,457
Accumulated Depreciation	$ 512,634			512,634
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,263,457
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 512,634
Operating Properties [Member] | 8910 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				527,873
Initial Cost of Buildings				4,959,206
Costs Capitalized Subsequent to Acquisition				360,851
Land and Improvements				527,873
Building and Improvements				5,320,057
Gross Amount Carried at End of Period	$ 5,847,930			5,847,930
Accumulated Depreciation	$ 814,596			814,596
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,847,930
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 814,596
Operating Properties [Member] | 8916 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				557,730
Initial Cost of Buildings				5,785,333
Costs Capitalized Subsequent to Acquisition				534,333
Land and Improvements				557,730
Building and Improvements				6,319,666
Gross Amount Carried at End of Period	$ 6,877,396			6,877,396
Accumulated Depreciation	$ 1,149,035			1,149,035
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,877,396
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,149,035
Operating Properties [Member] | 8924 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				654,713
Initial Cost of Buildings				5,365,823
Costs Capitalized Subsequent to Acquisition				(57,050)
Land and Improvements				654,713
Building and Improvements				5,308,773
Gross Amount Carried at End of Period	$ 5,963,486			5,963,486
Accumulated Depreciation	$ 135,996			135,996
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,963,486
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 135,996
Operating Properties [Member] | 2601 Indian River Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Chesapeake, VA
Encumbrances				0
Initial Cost of Land				1,711,746
Initial Cost of Buildings				10,418,032
Costs Capitalized Subsequent to Acquisition				494,065
Land and Improvements				1,711,746
Building and Improvements				10,912,097
Gross Amount Carried at End of Period	$ 12,623,843			12,623,843
Accumulated Depreciation	$ 1,619,711			1,619,711
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,623,843
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,619,711
Operating Properties [Member] | 1540 S 54th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Cicero, IL
Encumbrances				0
Initial Cost of Land				3,540,236
Initial Cost of Buildings				20,130,552
Costs Capitalized Subsequent to Acquisition				930,603
Land and Improvements				3,540,236
Building and Improvements				21,061,155
Gross Amount Carried at End of Period	$ 24,601,391			24,601,391
Accumulated Depreciation	$ 3,002,292			3,002,292
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 24,601,391
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,002,292
Operating Properties [Member] | 4650 Lake Forest Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Cincinnati, OH
Encumbrances				0
Initial Cost of Land				1,030,242
Initial Cost of Buildings				4,003,024
Costs Capitalized Subsequent to Acquisition				365,499
Land and Improvements				1,030,242
Building and Improvements				4,368,522
Gross Amount Carried at End of Period	$ 5,398,764			5,398,764
Accumulated Depreciation	$ 700,153			700,153
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,398,764
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 700,153
Operating Properties [Member] | 4750 Lake Forest Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Cincinnati, OH
Encumbrances				0
Initial Cost of Land				1,138,166
Initial Cost of Buildings				5,914,789
Costs Capitalized Subsequent to Acquisition				230,664
Land and Improvements				1,138,166
Building and Improvements				6,145,453
Gross Amount Carried at End of Period	$ 7,283,619			7,283,619
Accumulated Depreciation	$ 938,347			938,347
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,283,619
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 938,347
Operating Properties [Member] | 9645 Gerwig Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Columbia, MD
Encumbrances				0
Initial Cost of Land				1,915,960
Initial Cost of Buildings				6,461,228
Costs Capitalized Subsequent to Acquisition				322,982
Land and Improvements				1,915,960
Building and Improvements				6,784,210
Gross Amount Carried at End of Period	$ 8,700,170			8,700,170
Accumulated Depreciation	$ 1,097,619			1,097,619
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,700,170
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,097,619
Operating Properties [Member] | 2550 John Glenn Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Columbus, OH
Encumbrances				0
Initial Cost of Land				540,601
Initial Cost of Buildings				5,129,342
Costs Capitalized Subsequent to Acquisition				1,072,989
Land and Improvements				540,601
Building and Improvements				6,202,331
Gross Amount Carried at End of Period	$ 6,742,932			6,742,932
Accumulated Depreciation	$ 823,054			823,054
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,742,932
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 823,054
Operating Properties [Member] | 3800 Twin Creeks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Columbus, OH
Encumbrances				0
Initial Cost of Land				549,393
Initial Cost of Buildings				4,643,302
Costs Capitalized Subsequent to Acquisition				497,947
Land and Improvements				549,393
Building and Improvements				5,141,249
Gross Amount Carried at End of Period	$ 5,690,642			5,690,642
Accumulated Depreciation	$ 735,305			735,305
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,690,642
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 735,305
Operating Properties [Member] | 330 South Royal Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Coppell, TX
Encumbrances				0
Initial Cost of Land				2,091,426
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				11,407,128
Land and Improvements				2,091,426
Building and Improvements				11,407,128
Gross Amount Carried at End of Period	$ 13,498,554			13,498,554
Accumulated Depreciation	$ 876,255			876,255
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,498,554
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 876,255
Operating Properties [Member] | 455 Airline Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Coppell, TX
Encumbrances				0
Initial Cost of Land				312,701
Initial Cost of Buildings				2,311,531
Costs Capitalized Subsequent to Acquisition				489,922
Land and Improvements				312,701
Building and Improvements				2,801,453
Gross Amount Carried at End of Period	$ 3,114,154			3,114,154
Accumulated Depreciation	$ 475,079			475,079
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,114,154
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 475,079
Operating Properties [Member] | 2130 Baldwin Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Crofton, MD
Encumbrances				0
Initial Cost of Land				3,172,032
Initial Cost of Buildings				7,350,782
Costs Capitalized Subsequent to Acquisition				419,529
Land and Improvements				3,172,032
Building and Improvements				7,770,311
Gross Amount Carried at End of Period	$ 10,942,343			10,942,343
Accumulated Depreciation	$ 1,188,917			1,188,917
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,942,343
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,188,917
Operating Properties [Member] | 329-333 Herrod Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dayton, NJ
Encumbrances				0
Initial Cost of Land				4,039,559
Initial Cost of Buildings				20,863,051
Costs Capitalized Subsequent to Acquisition				2,286,868
Land and Improvements				4,039,559
Building and Improvements				23,149,919
Gross Amount Carried at End of Period	$ 27,189,478			27,189,478
Accumulated Depreciation	$ 3,326,807			3,326,807
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 27,189,478
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,326,807
Operating Properties [Member] | 1250 Hall Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Deer Park, TX
Encumbrances				0
Initial Cost of Land				829,570
Initial Cost of Buildings				4,778,327
Costs Capitalized Subsequent to Acquisition				121,291
Land and Improvements				831,611
Building and Improvements				4,897,577
Gross Amount Carried at End of Period	$ 5,729,188			5,729,188
Accumulated Depreciation	$ 1,442,762			1,442,762
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,729,188
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,442,762
Operating Properties [Member] | 1680 Executive Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duluth, GA
Encumbrances				0
Initial Cost of Land				1,928,412
Initial Cost of Buildings				4,651,819
Costs Capitalized Subsequent to Acquisition				617,290
Land and Improvements				1,928,412
Building and Improvements				5,269,109
Gross Amount Carried at End of Period	$ 7,197,521			7,197,521
Accumulated Depreciation	$ 1,077,104			1,077,104
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,197,521
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,077,104
Operating Properties [Member] | 1700 Executive Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duluth, GA
Encumbrances				0
Initial Cost of Land				1,082,072
Initial Cost of Buildings				2,496,599
Costs Capitalized Subsequent to Acquisition				573,982
Land and Improvements				1,082,072
Building and Improvements				3,070,581
Gross Amount Carried at End of Period	$ 4,152,653			4,152,653
Accumulated Depreciation	$ 621,884			621,884
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,152,653
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 621,884
Operating Properties [Member] | 2670 Breckinridge Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duluth, GA
Encumbrances				0
Initial Cost of Land				1,676,415
Initial Cost of Buildings				4,567,592
Costs Capitalized Subsequent to Acquisition				927,539
Land and Improvements				1,676,415
Building and Improvements				5,495,132
Gross Amount Carried at End of Period	$ 7,171,547			7,171,547
Accumulated Depreciation	$ 878,785			878,785
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,171,547
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 878,785
Operating Properties [Member] | 170 Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duncan, SC
Encumbrances				0
Initial Cost of Land				598,348
Initial Cost of Buildings				3,643,756
Costs Capitalized Subsequent to Acquisition				573,870
Land and Improvements				598,918
Building and Improvements				4,217,056
Gross Amount Carried at End of Period	$ 4,815,974			4,815,974
Accumulated Depreciation	$ 1,316,005			1,316,005
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,815,974
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,316,005
Operating Properties [Member] | 190 Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duncan, SC
Encumbrances				0
Initial Cost of Land				551,663
Initial Cost of Buildings				3,310,993
Costs Capitalized Subsequent to Acquisition				251,604
Land and Improvements				552,211
Building and Improvements				3,562,048
Gross Amount Carried at End of Period	$ 4,114,259			4,114,259
Accumulated Depreciation	$ 1,067,706			1,067,706
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,114,259
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,067,706
Operating Properties [Member] | 265 Parkway East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duncan, SC
Encumbrances				0
Initial Cost of Land				901,444
Initial Cost of Buildings				5,751,389
Costs Capitalized Subsequent to Acquisition				193,675
Land and Improvements				902,374
Building and Improvements				5,944,134
Gross Amount Carried at End of Period	$ 6,846,508			6,846,508
Accumulated Depreciation	$ 2,077,614			2,077,614
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,846,508
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,077,614
Operating Properties [Member] | 285 Parkway East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Duncan, SC
Encumbrances				0
Initial Cost of Land				975,433
Initial Cost of Buildings				5,851,990
Costs Capitalized Subsequent to Acquisition				525,729
Land and Improvements				976,393
Building and Improvements				6,376,759
Gross Amount Carried at End of Period	$ 7,353,152			7,353,152
Accumulated Depreciation	$ 1,901,005			1,901,005
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,353,152
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,901,005
Operating Properties [Member] | 1000 Parliament Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				2,229,000
Initial Cost of Buildings				7,064,506
Costs Capitalized Subsequent to Acquisition				792,599
Land and Improvements				2,229,000
Building and Improvements				7,857,105
Gross Amount Carried at End of Period	$ 10,086,105			10,086,105
Accumulated Depreciation	$ 791,102			791,102
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,086,105
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 791,102
Operating Properties [Member] | 4226 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				1,440,000
Initial Cost of Buildings				7,932,265
Costs Capitalized Subsequent to Acquisition				289,576
Land and Improvements				1,440,000
Building and Improvements				8,221,841
Gross Amount Carried at End of Period	$ 9,661,841			9,661,841
Accumulated Depreciation	$ 954,792			954,792
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,661,841
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 954,792
Operating Properties [Member] | 4227 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				1,500,000
Initial Cost of Buildings				5,624,030
Costs Capitalized Subsequent to Acquisition				235,182
Land and Improvements				1,500,000
Building and Improvements				5,859,211
Gross Amount Carried at End of Period	$ 7,359,211			7,359,211
Accumulated Depreciation	$ 534,911			534,911
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,359,211
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 534,911
Operating Properties [Member] | 4234 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				1,440,000
Initial Cost of Buildings				7,356,161
Costs Capitalized Subsequent to Acquisition				(78,204)
Land and Improvements				1,440,000
Building and Improvements				7,277,957
Gross Amount Carried at End of Period	$ 8,717,957			8,717,957
Accumulated Depreciation	$ 768,425			768,425
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,717,957
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 768,425
Operating Properties [Member] | 4300 Emperor Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				1,576,500
Initial Cost of Buildings				4,240,961
Costs Capitalized Subsequent to Acquisition				5,859
Land and Improvements				1,576,500
Building and Improvements				4,246,820
Gross Amount Carried at End of Period	$ 5,823,320			5,823,320
Accumulated Depreciation	$ 424,518			424,518
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,823,320
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 424,518
Operating Properties [Member] | 1957 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				1,844,943
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,946,981
Land and Improvements				3,091,046
Building and Improvements				6,700,878
Gross Amount Carried at End of Period	$ 9,791,924			9,791,924
Accumulated Depreciation	$ 206,273			206,273
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,791,924
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 206,273
Operating Properties [Member] | 3169 Dodd Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eagan, MN
Encumbrances				0
Initial Cost of Land				988,594
Initial Cost of Buildings				6,586,907
Costs Capitalized Subsequent to Acquisition				394,649
Land and Improvements				988,594
Building and Improvements				6,981,556
Gross Amount Carried at End of Period	$ 7,970,150			7,970,150
Accumulated Depreciation	$ 1,123,900			1,123,900
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,970,150
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,123,900
Operating Properties [Member] | 3711 Kennebec Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eagan, MN
Encumbrances				0
Initial Cost of Land				999,702
Initial Cost of Buildings				4,042,589
Costs Capitalized Subsequent to Acquisition				(2,670)
Land and Improvements				999,702
Building and Improvements				4,039,919
Gross Amount Carried at End of Period	$ 5,039,621			5,039,621
Accumulated Depreciation	$ 721,854			721,854
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,039,621
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 721,854
Operating Properties [Member] | 917 Lone Oak Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eagan, MN
Encumbrances				0
Initial Cost of Land				1,493,115
Initial Cost of Buildings				6,120,455
Costs Capitalized Subsequent to Acquisition				976,663
Land and Improvements				1,493,115
Building and Improvements				7,097,118
Gross Amount Carried at End of Period	$ 8,590,233			8,590,233
Accumulated Depreciation	$ 1,159,254			1,159,254
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,590,233
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,159,254
Operating Properties [Member] | 10301-10305 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				120,622
Initial Cost of Buildings				1,085,226
Costs Capitalized Subsequent to Acquisition				310,448
Land and Improvements				118,300
Building and Improvements				1,397,996
Gross Amount Carried at End of Period	$ 1,516,296			1,516,296
Accumulated Depreciation	$ 699,145			699,145
Date of Construction or Acquisition	1,984
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,516,296
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 699,145
Operating Properties [Member] | 10321 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				145,198
Initial Cost of Buildings				1,305,700
Costs Capitalized Subsequent to Acquisition				616,746
Land and Improvements				142,399
Building and Improvements				1,925,245
Gross Amount Carried at End of Period	$ 2,067,644			2,067,644
Accumulated Depreciation	$ 968,278			968,278
Date of Construction or Acquisition	1,984
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,067,644
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 968,278
Operating Properties [Member] | 10333 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				110,746
Initial Cost of Buildings				995,868
Costs Capitalized Subsequent to Acquisition				285,918
Land and Improvements				108,610
Building and Improvements				1,283,922
Gross Amount Carried at End of Period	$ 1,392,532			1,392,532
Accumulated Depreciation	$ 656,683			656,683
Date of Construction or Acquisition	1,984
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,392,532
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 656,683
Operating Properties [Member] | 10349-10357 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				275,903
Initial Cost of Buildings				2,481,666
Costs Capitalized Subsequent to Acquisition				954,195
Land and Improvements				270,584
Building and Improvements				3,441,180
Gross Amount Carried at End of Period	$ 3,711,764			3,711,764
Accumulated Depreciation	$ 1,842,058			1,842,058
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,711,764
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,842,058
Operating Properties [Member] | 10365-10375 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				291,077
Initial Cost of Buildings				2,618,194
Costs Capitalized Subsequent to Acquisition				1,585,889
Land and Improvements				285,464
Building and Improvements				4,209,696
Gross Amount Carried at End of Period	$ 4,495,160			4,495,160
Accumulated Depreciation	$ 1,900,290			1,900,290
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,495,160
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,900,290
Operating Properties [Member] | 10393-10394 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				269,618
Initial Cost of Buildings				2,423,318
Costs Capitalized Subsequent to Acquisition				2,527,379
Land and Improvements				264,419
Building and Improvements				4,955,896
Gross Amount Carried at End of Period	$ 5,220,315			5,220,315
Accumulated Depreciation	$ 2,194,769			2,194,769
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,220,315
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,194,769
Operating Properties [Member] | 7075 Flying Cloud Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				10,232,831
Initial Cost of Buildings				10,855,851
Costs Capitalized Subsequent to Acquisition				4,057,532
Land and Improvements				9,967,306
Building and Improvements				15,178,907
Gross Amount Carried at End of Period	$ 25,146,213			25,146,213
Accumulated Depreciation	$ 3,578,639			3,578,639
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 25,146,213
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,578,639
Operating Properties [Member] | 7078 Shady Oak Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				343,093
Initial Cost of Buildings				3,085,795
Costs Capitalized Subsequent to Acquisition				1,624,923
Land and Improvements				336,481
Building and Improvements				4,717,330
Gross Amount Carried at End of Period	$ 5,053,811			5,053,811
Accumulated Depreciation	$ 2,636,995			2,636,995
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,053,811
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,636,995
Operating Properties [Member] | 1 Truman Drive South [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Edison, NJ
Encumbrances				0
Initial Cost of Land				27,862,573
Initial Cost of Buildings				19,426,947
Costs Capitalized Subsequent to Acquisition				703,083
Land and Improvements				27,862,573
Building and Improvements				20,130,030
Gross Amount Carried at End of Period	$ 47,992,603			47,992,603
Accumulated Depreciation	$ 19,993			19,993
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 47,992,603
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 19,993
Operating Properties [Member] | 2250 Arthur Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Elk Grove, IL
Encumbrances				0
Initial Cost of Land				1,403,196
Initial Cost of Buildings				2,386,396
Costs Capitalized Subsequent to Acquisition				149,289
Land and Improvements				1,403,196
Building and Improvements				2,535,685
Gross Amount Carried at End of Period	$ 3,938,881			3,938,881
Accumulated Depreciation	$ 392,856			392,856
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,938,881
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 392,856
Operating Properties [Member] | 6600 Business Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Elkridge, MD
Encumbrances				0
Initial Cost of Land				3,680,220
Initial Cost of Buildings				14,671,910
Costs Capitalized Subsequent to Acquisition				703,042
Land and Improvements				3,680,220
Building and Improvements				15,374,952
Gross Amount Carried at End of Period	$ 19,055,172			19,055,172
Accumulated Depreciation	$ 1,968,894			1,968,894
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 19,055,172
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,968,894
Operating Properties [Member] | 6675 Business Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Elkridge, MD
Encumbrances				0
Initial Cost of Land				2,421,854
Initial Cost of Buildings				9,730,192
Costs Capitalized Subsequent to Acquisition				695,870
Land and Improvements				2,421,854
Building and Improvements				10,426,062
Gross Amount Carried at End of Period	$ 12,847,916			12,847,916
Accumulated Depreciation	$ 1,338,178			1,338,178
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,847,916
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,338,178
Operating Properties [Member] | 7351 Coca Cola Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Elkridge, MD
Encumbrances				0
Initial Cost of Land				1,897,044
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,419,134
Land and Improvements				3,023,417
Building and Improvements				6,292,761
Gross Amount Carried at End of Period	$ 9,316,178			9,316,178
Accumulated Depreciation	$ 1,996,209			1,996,209
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,316,178
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,996,209
Operating Properties [Member] | 21705-21707 Mississippi Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Elwood, IL
Encumbrances				0
Initial Cost of Land				10,594,259
Initial Cost of Buildings				30,329,802
Costs Capitalized Subsequent to Acquisition				1,557,857
Land and Improvements				10,594,259
Building and Improvements				31,887,660
Gross Amount Carried at End of Period	$ 42,481,919			42,481,919
Accumulated Depreciation	$ 5,256,343			5,256,343
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 42,481,919
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 5,256,343
Operating Properties [Member] | 27143 Elwood International Port Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Elwood, IL
Encumbrances				0
Initial Cost of Land				6,022,000
Initial Cost of Buildings				5,612,934
Costs Capitalized Subsequent to Acquisition				587,921
Land and Improvements				6,022,000
Building and Improvements				6,200,855
Gross Amount Carried at End of Period	$ 12,222,855			12,222,855
Accumulated Depreciation	$ 1,087,835			1,087,835
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,222,855
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,087,835
Operating Properties [Member] | 1800 Donaldson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Erlanger, KY
Encumbrances				0
Initial Cost of Land				0
Initial Cost of Buildings				13,211,604
Costs Capitalized Subsequent to Acquisition				762,210
Land and Improvements				0
Building and Improvements				13,973,814
Gross Amount Carried at End of Period	$ 13,973,814			13,973,814
Accumulated Depreciation	$ 3,972,728			3,972,728
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,973,814
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,972,728
Operating Properties [Member] | 6880 Fairfield Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fairfield, OH
Encumbrances				0
Initial Cost of Land				412,136
Initial Cost of Buildings				3,029,177
Costs Capitalized Subsequent to Acquisition				146,616
Land and Improvements				412,136
Building and Improvements				3,175,793
Gross Amount Carried at End of Period	$ 3,587,929			3,587,929
Accumulated Depreciation	$ 450,893			450,893
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,587,929
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 450,893
Operating Properties [Member] | 7000-7018 Fairfield Business [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fairfield, OH
Encumbrances				0
Initial Cost of Land				367,925
Initial Cost of Buildings				2,205,817
Costs Capitalized Subsequent to Acquisition				177,833
Land and Improvements				386,928
Building and Improvements				2,364,647
Gross Amount Carried at End of Period	$ 2,751,575			2,751,575
Accumulated Depreciation	$ 325,215			325,215
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,751,575
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 325,215
Operating Properties [Member] | 10721 Jasmine Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fontana, CA
Encumbrances				0
Initial Cost of Land				11,427,061
Initial Cost of Buildings				23,784,779
Costs Capitalized Subsequent to Acquisition				3,739,838
Land and Improvements				11,427,061
Building and Improvements				27,524,617
Gross Amount Carried at End of Period	$ 38,951,678			38,951,678
Accumulated Depreciation	$ 1,817,042			1,817,042
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 38,951,678
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,817,042
Operating Properties [Member] | 2000 Southpointe Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Forest Park, GA
Encumbrances				0
Initial Cost of Land				756,221
Initial Cost of Buildings				9,115,626
Costs Capitalized Subsequent to Acquisition				662,099
Land and Improvements				756,221
Building and Improvements				9,777,725
Gross Amount Carried at End of Period	$ 10,533,946			10,533,946
Accumulated Depreciation	$ 1,464,610			1,464,610
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,533,946
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,464,610
Operating Properties [Member] | 1400 NW 65th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fort Lauderdale, FL
Encumbrances				0
Initial Cost of Land				545,480
Initial Cost of Buildings				2,540,210
Costs Capitalized Subsequent to Acquisition				86,121
Land and Improvements				545,480
Building and Improvements				2,626,331
Gross Amount Carried at End of Period	$ 3,171,811			3,171,811
Accumulated Depreciation	341,109			341,109
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	3,171,811
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 341,109
Operating Properties [Member] | 6500 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fort Lauderdale, FL
Encumbrances				0
Initial Cost of Land				0
Initial Cost of Buildings				3,064,734
Costs Capitalized Subsequent to Acquisition				521,736
Land and Improvements				0
Building and Improvements				3,586,470
Gross Amount Carried at End of Period	$ 3,586,470			3,586,470
Accumulated Depreciation	$ 540,454			540,454
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,586,470
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 540,454
Operating Properties [Member] | 6501 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fort Lauderdale, FL
Encumbrances				0
Initial Cost of Land				519,984
Initial Cost of Buildings				2,677,465
Costs Capitalized Subsequent to Acquisition				312,381
Land and Improvements				519,984
Building and Improvements				2,989,846
Gross Amount Carried at End of Period	$ 3,509,830			3,509,830
Accumulated Depreciation	$ 346,270			346,270
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,509,830
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 346,270
Operating Properties [Member] | 6600 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fort Lauderdale, FL
Encumbrances				0
Initial Cost of Land				0
Initial Cost of Buildings				2,988,181
Costs Capitalized Subsequent to Acquisition				267,630
Land and Improvements				0
Building and Improvements				3,255,811
Gross Amount Carried at End of Period	$ 3,255,811			3,255,811
Accumulated Depreciation	$ 505,594			505,594
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,255,811
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 505,594
Operating Properties [Member] | 9601 Cosner Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Fredericksburg, VA
Encumbrances				0
Initial Cost of Land				475,262
Initial Cost of Buildings				3,917,234
Costs Capitalized Subsequent to Acquisition				387,315
Land and Improvements				475,262
Building and Improvements				4,304,549
Gross Amount Carried at End of Period	$ 4,779,811			4,779,811
Accumulated Depreciation	$ 2,372,215			2,372,215
Date of Construction or Acquisition	1,995
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,779,811
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,372,215
Operating Properties [Member] | 5410 - 5430 Northwest 33rd Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Ft. Lauderdale, FL
Encumbrances				0
Initial Cost of Land				603,776
Initial Cost of Buildings				4,176,238
Costs Capitalized Subsequent to Acquisition				1,990,114
Land and Improvements				625,111
Building and Improvements				6,145,017
Gross Amount Carried at End of Period	$ 6,770,128			6,770,128
Accumulated Depreciation	$ 3,281,803			3,281,803
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,770,128
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,281,803
Operating Properties [Member] | 12601 Industry Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Garden Grove, CA
Encumbrances				0
Initial Cost of Land				2,048,143
Initial Cost of Buildings				1,088,697
Costs Capitalized Subsequent to Acquisition				70,611
Land and Improvements				2,048,143
Building and Improvements				1,159,308
Gross Amount Carried at End of Period	$ 3,207,451			3,207,451
Accumulated Depreciation	$ 276,355			276,355
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,207,451
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 276,355
Operating Properties [Member] | 12641 Industry Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Garden Grove, CA
Encumbrances				0
Initial Cost of Land				3,766,822
Initial Cost of Buildings				2,539,214
Costs Capitalized Subsequent to Acquisition				133,026
Land and Improvements				3,766,822
Building and Improvements				2,672,240
Gross Amount Carried at End of Period	$ 6,439,062			6,439,062
Accumulated Depreciation	$ 408,964			408,964
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,439,062
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 408,964
Operating Properties [Member] | 12681-12691 Pala Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Garden Grove, CA
Encumbrances				0
Initial Cost of Land				5,221,102
Initial Cost of Buildings				3,225,596
Costs Capitalized Subsequent to Acquisition				83,715
Land and Improvements				5,220,148
Building and Improvements				3,310,265
Gross Amount Carried at End of Period	$ 8,530,413			8,530,413
Accumulated Depreciation	$ 359,715			359,715
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,530,413
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 359,715
Operating Properties [Member] | 850 S Jupiter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Garland, TX
Encumbrances				0
Initial Cost of Land				799,707
Initial Cost of Buildings				6,122,065
Costs Capitalized Subsequent to Acquisition				506,894
Land and Improvements				799,707
Building and Improvements				6,628,959
Gross Amount Carried at End of Period	$ 7,428,666			7,428,666
Accumulated Depreciation	$ 1,005,200			1,005,200
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,428,666
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,005,200
Operating Properties [Member] | 2510 W Main Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Grand Prairie, TX
Encumbrances				0
Initial Cost of Land				1,785,741
Initial Cost of Buildings				11,158,818
Costs Capitalized Subsequent to Acquisition				1,677,983
Land and Improvements				1,785,741
Building and Improvements				12,836,801
Gross Amount Carried at End of Period	$ 14,622,542			14,622,542
Accumulated Depreciation	$ 2,144,063			2,144,063
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,622,542
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,144,063
Operating Properties [Member] | 4251 North Highway 121 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Grapevine, TX
Encumbrances				0
Initial Cost of Land				1,165,780
Initial Cost of Buildings				7,799,270
Costs Capitalized Subsequent to Acquisition				422,871
Land and Improvements				1,165,780
Building and Improvements				8,222,140
Gross Amount Carried at End of Period	$ 9,387,920			9,387,920
Accumulated Depreciation	$ 1,322,370			1,322,370
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,387,920
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,322,370
Operating Properties [Member] | 1150 Pleasant Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greensboro, NC
Encumbrances				0
Initial Cost of Land				1,547,811
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				14,336,534
Land and Improvements				3,712,683
Building and Improvements				12,171,662
Gross Amount Carried at End of Period	$ 15,884,345			15,884,345
Accumulated Depreciation	$ 2,930,846			2,930,846
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,884,345
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,930,846
Operating Properties [Member] | 25 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greenville, SC
Encumbrances				0
Initial Cost of Land				288,823
Initial Cost of Buildings				3,441,512
Costs Capitalized Subsequent to Acquisition				(60,552)
Land and Improvements				288,823
Building and Improvements				3,380,960
Gross Amount Carried at End of Period	$ 3,669,783			3,669,783
Accumulated Depreciation	$ 386,571			386,571
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,669,783
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 386,571
Operating Properties [Member] | 45 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greenville, SC
Encumbrances				0
Initial Cost of Land				818,114
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,737,211
Land and Improvements				825,529
Building and Improvements				4,729,796
Gross Amount Carried at End of Period	$ 5,555,325			5,555,325
Accumulated Depreciation	$ 1,273,122			1,273,122
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,555,325
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,273,122
Operating Properties [Member] | 2011 Southtech Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greenwood, IN
Encumbrances				0
Initial Cost of Land				223,702
Initial Cost of Buildings				3,574,142
Costs Capitalized Subsequent to Acquisition				348,881
Land and Improvements				223,702
Building and Improvements				3,923,023
Gross Amount Carried at End of Period	$ 4,146,725			4,146,725
Accumulated Depreciation	$ 673,141			673,141
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,146,725
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 673,141
Operating Properties [Member] | 2121 Southtech Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greenwood, IN
Encumbrances				0
Initial Cost of Land				272,823
Initial Cost of Buildings				3,606,920
Costs Capitalized Subsequent to Acquisition				425,631
Land and Improvements				272,823
Building and Improvements				4,032,552
Gross Amount Carried at End of Period	$ 4,305,375			4,305,375
Accumulated Depreciation	$ 868,917			868,917
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,305,375
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 868,917
Operating Properties [Member] | 800 Commerce Parkway West Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greenwood, IN
Encumbrances				0
Initial Cost of Land				1,374,664
Initial Cost of Buildings				29,963,830
Costs Capitalized Subsequent to Acquisition				2,112,538
Land and Improvements				1,374,664
Building and Improvements				32,076,368
Gross Amount Carried at End of Period	$ 33,451,032			33,451,032
Accumulated Depreciation	$ 4,662,009			4,662,009
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 33,451,032
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,662,009
Operating Properties [Member] | 110 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				555,549
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,339,922
Land and Improvements				1,241,531
Building and Improvements				5,653,940
Gross Amount Carried at End of Period	$ 6,895,471			6,895,471
Accumulated Depreciation	$ 472,790			472,790
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,895,471
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 472,790
Operating Properties [Member] | 140 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				1,243,100
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,460,810
Land and Improvements				1,255,751
Building and Improvements				6,448,159
Gross Amount Carried at End of Period	$ 7,703,910			7,703,910
Accumulated Depreciation	$ 594,631			594,631
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,703,910
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 594,631
Operating Properties [Member] | 11835 Newgate Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hagerstown, MD
Encumbrances				0
Initial Cost of Land				14,121,622
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				23,024,333
Land and Improvements				14,121,622
Building and Improvements				23,024,333
Gross Amount Carried at End of Period	$ 37,145,955			37,145,955
Accumulated Depreciation	$ 2,135,910			2,135,910
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 37,145,955
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,135,910
Operating Properties [Member] | 11841 Newgate Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hagerstown, MD
Encumbrances				0
Initial Cost of Land				3,356,207
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				30,679,055
Land and Improvements				9,741,685
Building and Improvements				24,293,577
Gross Amount Carried at End of Period	$ 34,035,262			34,035,262
Accumulated Depreciation	$ 6,578,678			6,578,678
Date of Construction or Acquisition	2,008
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 34,035,262
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,578,678
Operating Properties [Member] | 1560 Hunter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover Park, IL
Encumbrances				0
Initial Cost of Land				2,639,734
Initial Cost of Buildings				12,310,741
Costs Capitalized Subsequent to Acquisition				1,072,313
Land and Improvements				2,639,734
Building and Improvements				13,383,054
Gross Amount Carried at End of Period	$ 16,022,788			16,022,788
Accumulated Depreciation	$ 1,884,363			1,884,363
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 16,022,788
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,884,363
Operating Properties [Member] | 1575 Hunter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover Park, IL
Encumbrances				0
Initial Cost of Land				3,293,284
Initial Cost of Buildings				17,235,926
Costs Capitalized Subsequent to Acquisition				1,174,459
Land and Improvements				3,293,284
Building and Improvements				18,410,385
Gross Amount Carried at End of Period	$ 21,703,669			21,703,669
Accumulated Depreciation	$ 2,655,120			2,655,120
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,703,669
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,655,120
Operating Properties [Member] | 7361 Coca Cola Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover, MD
Encumbrances				0
Initial Cost of Land				2,245,187
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,668,306
Land and Improvements				3,822,710
Building and Improvements				8,090,783
Gross Amount Carried at End of Period	$ 11,913,493			11,913,493
Accumulated Depreciation	$ 1,741,059			1,741,059
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,913,493
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,741,059
Operating Properties [Member] | 7460 New Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover, MD
Encumbrances				0
Initial Cost of Land				3,785,446
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				8,128,924
Land and Improvements				3,796,023
Building and Improvements				8,118,347
Gross Amount Carried at End of Period	$ 11,914,370			11,914,370
Accumulated Depreciation	$ 587,264			587,264
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,914,370
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 587,264
Operating Properties [Member] | 7462 New Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover, MD
Encumbrances				0
Initial Cost of Land				4,059,337
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,491,548
Land and Improvements				4,070,629
Building and Improvements				7,480,256
Gross Amount Carried at End of Period	$ 11,550,885			11,550,885
Accumulated Depreciation	$ 511,893			511,893
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,550,885
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 511,893
Operating Properties [Member] | 500 McCarthy Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Harrisburg, PA
Encumbrances				0
Initial Cost of Land				5,194,872
Initial Cost of Buildings				19,991,436
Costs Capitalized Subsequent to Acquisition				5,020,100
Land and Improvements				5,687,013
Building and Improvements				24,519,395
Gross Amount Carried at End of Period	$ 30,206,408			30,206,408
Accumulated Depreciation	$ 9,042,285			9,042,285
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 30,206,408
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 9,042,285
Operating Properties [Member] | 600 Industrial Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Harrisburg, PA
Encumbrances				0
Initial Cost of Land				7,743,800
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				27,803,943
Land and Improvements				9,368,557
Building and Improvements				26,179,186
Gross Amount Carried at End of Period	$ 35,547,743			35,547,743
Accumulated Depreciation	$ 7,808,361			7,808,361
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 35,547,743
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 7,808,361
Operating Properties [Member] | 7195 Grayson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Harrisburg, PA
Encumbrances				0
Initial Cost of Land				464,534
Initial Cost of Buildings				6,066,272
Costs Capitalized Subsequent to Acquisition				251,813
Land and Improvements				464,534
Building and Improvements				6,318,085
Gross Amount Carried at End of Period	$ 6,782,619			6,782,619
Accumulated Depreciation	$ 850,896			850,896
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,782,619
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 850,896
Operating Properties [Member] | 7253 Grayson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Harrisburg, PA
Encumbrances				0
Initial Cost of Land				954,130
Initial Cost of Buildings				10,585,367
Costs Capitalized Subsequent to Acquisition				583,272
Land and Improvements				954,130
Building and Improvements				11,168,639
Gross Amount Carried at End of Period	$ 12,122,769			12,122,769
Accumulated Depreciation	$ 1,466,551			1,466,551
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,122,769
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,466,551
Operating Properties [Member] | 12537 Cerise Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hawthorne, CA
Encumbrances				0
Initial Cost of Land				2,203,194
Initial Cost of Buildings				5,758,809
Costs Capitalized Subsequent to Acquisition				1,461,971
Land and Improvements				2,203,194
Building and Improvements				7,220,780
Gross Amount Carried at End of Period	$ 9,423,974			9,423,974
Accumulated Depreciation	$ 728,059			728,059
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,423,974
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 728,059
Operating Properties [Member] | 1010 Petersburg Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hebron, KY
Encumbrances				0
Initial Cost of Land				305,471
Initial Cost of Buildings				5,434,505
Costs Capitalized Subsequent to Acquisition				(819,546)
Land and Improvements				305,471
Building and Improvements				4,614,959
Gross Amount Carried at End of Period	$ 4,920,430			4,920,430
Accumulated Depreciation	$ 729,928			729,928
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,920,430
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 729,928
Operating Properties [Member] | 785 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hebron, KY
Encumbrances				0
Initial Cost of Land				401,410
Initial Cost of Buildings				3,087,899
Costs Capitalized Subsequent to Acquisition				511,831
Land and Improvements				401,410
Building and Improvements				3,599,730
Gross Amount Carried at End of Period	$ 4,001,140			4,001,140
Accumulated Depreciation	$ 851,287			851,287
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,001,140
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 851,287
Operating Properties [Member] | 805 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hebron, KY
Encumbrances				0
Initial Cost of Land				292,096
Initial Cost of Buildings				2,502,486
Costs Capitalized Subsequent to Acquisition				163,832
Land and Improvements				292,096
Building and Improvements				2,666,317
Gross Amount Carried at End of Period	$ 2,958,413			2,958,413
Accumulated Depreciation	$ 460,511			460,511
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,958,413
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 460,511
Operating Properties [Member] | 825 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hebron, KY
Encumbrances				0
Initial Cost of Land				370,149
Initial Cost of Buildings				3,095,116
Costs Capitalized Subsequent to Acquisition				435,793
Land and Improvements				370,149
Building and Improvements				3,530,910
Gross Amount Carried at End of Period	$ 3,901,059			3,901,059
Accumulated Depreciation	$ 599,942			599,942
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,901,059
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 599,942
Operating Properties [Member] | 845 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hebron, KY
Encumbrances				0
Initial Cost of Land				444,318
Initial Cost of Buildings				3,811,889
Costs Capitalized Subsequent to Acquisition				316,672
Land and Improvements				444,318
Building and Improvements				4,128,561
Gross Amount Carried at End of Period	$ 4,572,879			4,572,879
Accumulated Depreciation	$ 666,370			666,370
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,572,879
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 666,370
Operating Properties [Member] | 4198 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				94,274
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,276,671
Land and Improvements				791,880
Building and Improvements				5,579,065
Gross Amount Carried at End of Period	$ 6,370,945			6,370,945
Accumulated Depreciation	$ 1,621,575			1,621,575
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,370,945
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,621,575
Operating Properties [Member] | 4183 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				122,203
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,214,906
Land and Improvements				526,266
Building and Improvements				2,810,843
Gross Amount Carried at End of Period	$ 3,337,109			3,337,109
Accumulated Depreciation	$ 1,311,124			1,311,124
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,337,109
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,311,124
Operating Properties [Member] | 4189 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				100,106
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,584,103
Land and Improvements				431,106
Building and Improvements				3,253,103
Gross Amount Carried at End of Period	$ 3,684,209			3,684,209
Accumulated Depreciation	$ 1,652,112			1,652,112
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,684,209
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,652,112
Operating Properties [Member] | 4193 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				107,586
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,391,727
Land and Improvements				505,700
Building and Improvements				2,993,613
Gross Amount Carried at End of Period	$ 3,499,313			3,499,313
Accumulated Depreciation	$ 968,743			968,743
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,499,313
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 968,743
Operating Properties [Member] | 4328, 4336 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				521,122
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,624,655
Land and Improvements				825,092
Building and Improvements				5,320,685
Gross Amount Carried at End of Period	$ 6,145,777			6,145,777
Accumulated Depreciation	$ 2,596,135			2,596,135
Date of Construction or Acquisition	1,995
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,145,777
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,596,135
Operating Properties [Member] | 4344 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				484,001
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,152,416
Land and Improvements				173,623
Building and Improvements				3,462,794
Gross Amount Carried at End of Period	$ 3,636,417			3,636,417
Accumulated Depreciation	$ 1,866,989			1,866,989
Date of Construction or Acquisition	1,996
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,636,417
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,866,989
Operating Properties [Member] | 4380 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				282,996
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,209,713
Land and Improvements				283,368
Building and Improvements				2,209,341
Gross Amount Carried at End of Period	$ 2,492,709			2,492,709
Accumulated Depreciation	$ 1,199,039			1,199,039
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,492,709
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,199,039
Operating Properties [Member] | 4388 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				143,661
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,214,818
Land and Improvements				132,655
Building and Improvements				1,225,824
Gross Amount Carried at End of Period	$ 1,358,479			1,358,479
Accumulated Depreciation	$ 653,753			653,753
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,358,479
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 653,753
Operating Properties [Member] | 4475 Premier Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				748,693
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,806,962
Land and Improvements				1,525,421
Building and Improvements				6,030,234
Gross Amount Carried at End of Period	$ 7,555,655			7,555,655
Accumulated Depreciation	$ 1,429,865			1,429,865
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,555,655
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,429,865
Operating Properties [Member] | 4500 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				230,622
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,757,316
Land and Improvements				231,692
Building and Improvements				2,756,246
Gross Amount Carried at End of Period	$ 2,987,938			2,987,938
Accumulated Depreciation	$ 1,618,070			1,618,070
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,987,938
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,618,070
Operating Properties [Member] | 4501 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				319,289
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,133,118
Land and Improvements				320,450
Building and Improvements				3,131,957
Gross Amount Carried at End of Period	$ 3,452,407			3,452,407
Accumulated Depreciation	$ 1,976,183			1,976,183
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,452,407
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,976,183
Operating Properties [Member] | 4523 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				234,564
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,319,368
Land and Improvements				235,698
Building and Improvements				3,318,234
Gross Amount Carried at End of Period	$ 3,553,932			3,553,932
Accumulated Depreciation	$ 2,236,810			2,236,810
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,553,932
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,236,810
Operating Properties [Member] | 4524 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				182,810
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,838,325
Land and Improvements				183,888
Building and Improvements				2,837,247
Gross Amount Carried at End of Period	$ 3,021,135			3,021,135
Accumulated Depreciation	$ 1,804,718			1,804,718
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,021,135
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,804,718
Operating Properties [Member] | 9600 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				405,362
Initial Cost of Buildings				1,146,546
Costs Capitalized Subsequent to Acquisition				451,093
Land and Improvements				405,362
Building and Improvements				1,597,639
Gross Amount Carried at End of Period	$ 2,003,001			2,003,001
Accumulated Depreciation	$ 775,969			775,969
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,003,001
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 775,969
Operating Properties [Member] | Unit 5 Logix Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hinckley, UK
Encumbrances				0
Initial Cost of Land				10,547,677
Initial Cost of Buildings				29,691,911
Costs Capitalized Subsequent to Acquisition				(7,396,097)
Land and Improvements				8,608,489
Building and Improvements				24,235,002
Gross Amount Carried at End of Period	$ 32,843,491			32,843,491
Accumulated Depreciation	$ 3,350,056			3,350,056
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 32,843,491
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,350,056
Operating Properties [Member] | 1000 South Loop West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				509,351
Initial Cost of Buildings				3,549,504
Costs Capitalized Subsequent to Acquisition				938,122
Land and Improvements				509,351
Building and Improvements				4,487,626
Gross Amount Carried at End of Period	$ 4,996,977			4,996,977
Accumulated Depreciation	$ 835,033			835,033
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,996,977
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 835,033
Operating Properties [Member] | 10241 W Little York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				558,491
Initial Cost of Buildings				5,740,552
Costs Capitalized Subsequent to Acquisition				139,500
Land and Improvements				558,491
Building and Improvements				5,880,052
Gross Amount Carried at End of Period	$ 6,438,543			6,438,543
Accumulated Depreciation	$ 753,250			753,250
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,438,543
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 753,250
Operating Properties [Member] | 10245 W Little York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				426,927
Initial Cost of Buildings				3,460,513
Costs Capitalized Subsequent to Acquisition				380,296
Land and Improvements				426,927
Building and Improvements				3,840,809
Gross Amount Carried at End of Period	$ 4,267,736			4,267,736
Accumulated Depreciation	$ 795,963			795,963
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,267,736
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 795,963
Operating Properties [Member] | 10301 Round Up Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				545,501
Initial Cost of Buildings				2,927,700
Costs Capitalized Subsequent to Acquisition				961,929
Land and Improvements				545,501
Building and Improvements				3,889,628
Gross Amount Carried at End of Period	$ 4,435,129			4,435,129
Accumulated Depreciation	$ 585,432			585,432
Date of Construction or Acquisition	2,010
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,435,129
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 585,432
Operating Properties [Member] | 10305 Round Up Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,340,609
Initial Cost of Buildings				7,489,720
Costs Capitalized Subsequent to Acquisition				2,951,546
Land and Improvements				1,340,609
Building and Improvements				10,441,265
Gross Amount Carried at End of Period	$ 11,781,874			11,781,874
Accumulated Depreciation	$ 2,361,657			2,361,657
Date of Construction or Acquisition	2,010
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,781,874
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,361,657
Operating Properties [Member] | 1050 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				973,482
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,531,792
Land and Improvements				992,093
Building and Improvements				3,513,181
Gross Amount Carried at End of Period	$ 4,505,274			4,505,274
Accumulated Depreciation	$ 252,833			252,833
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,505,274
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 252,833
Operating Properties [Member] | 10607 Haddington Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				201,469
Initial Cost of Buildings				1,631,561
Costs Capitalized Subsequent to Acquisition				132,748
Land and Improvements				201,469
Building and Improvements				1,764,310
Gross Amount Carried at End of Period	$ 1,965,779			1,965,779
Accumulated Depreciation	$ 282,662			282,662
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,965,779
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 282,662
Operating Properties [Member] | 10735 West Little York Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,110,988
Initial Cost of Buildings				6,351,946
Costs Capitalized Subsequent to Acquisition				3,147,449
Land and Improvements				1,135,483
Building and Improvements				9,474,900
Gross Amount Carried at End of Period	$ 10,610,383			10,610,383
Accumulated Depreciation	$ 3,426,368			3,426,368
Date of Construction or Acquisition	2,000
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,610,383
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,426,368
Operating Properties [Member] | 10739 West Little York Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				797,931
Initial Cost of Buildings				5,950,894
Costs Capitalized Subsequent to Acquisition				339,014
Land and Improvements				799,560
Building and Improvements				6,288,279
Gross Amount Carried at End of Period	$ 7,087,839			7,087,839
Accumulated Depreciation	$ 2,419,437			2,419,437
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,087,839
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,419,437
Operating Properties [Member] | 11201 Greens Crossing Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,006,194
Initial Cost of Buildings				5,412,584
Costs Capitalized Subsequent to Acquisition				2,620,073
Land and Improvements				1,008,542
Building and Improvements				8,030,309
Gross Amount Carried at End of Period	$ 9,038,851			9,038,851
Accumulated Depreciation	$ 2,509,545			2,509,545
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,038,851
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,509,545
Operating Properties [Member] | 11220 Ella Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,505,855
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,417,101
Land and Improvements				1,534,644
Building and Improvements				7,388,312
Gross Amount Carried at End of Period	$ 8,922,956			8,922,956
Accumulated Depreciation	$ 529,511			529,511
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,922,956
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 529,511
Operating Properties [Member] | 1283 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				80,730
Initial Cost of Buildings				870,656
Costs Capitalized Subsequent to Acquisition				145,557
Land and Improvements				80,730
Building and Improvements				1,016,213
Gross Amount Carried at End of Period	$ 1,096,943			1,096,943
Accumulated Depreciation	$ 178,472			178,472
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,096,943
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 178,472
Operating Properties [Member] | 1287 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				146,654
Initial Cost of Buildings				1,620,780
Costs Capitalized Subsequent to Acquisition				55,679
Land and Improvements				146,654
Building and Improvements				1,676,458
Gross Amount Carried at End of Period	$ 1,823,112			1,823,112
Accumulated Depreciation	$ 280,919			280,919
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,823,112
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 280,919
Operating Properties [Member] | 1291 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				510,102
Initial Cost of Buildings				4,129,042
Costs Capitalized Subsequent to Acquisition				586,888
Land and Improvements				510,102
Building and Improvements				4,715,930
Gross Amount Carried at End of Period	$ 5,226,032			5,226,032
Accumulated Depreciation	$ 757,450			757,450
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,226,032
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 757,450
Operating Properties [Member] | 1416 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				218,850
Initial Cost of Buildings				1,639,902
Costs Capitalized Subsequent to Acquisition				558,311
Land and Improvements				218,850
Building and Improvements				2,198,212
Gross Amount Carried at End of Period	$ 2,417,062			2,417,062
Accumulated Depreciation	$ 407,593			407,593
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,417,062
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 407,593
Operating Properties [Member] | 1420 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				211,279
Initial Cost of Buildings				1,554,156
Costs Capitalized Subsequent to Acquisition				262,982
Land and Improvements				211,279
Building and Improvements				1,817,138
Gross Amount Carried at End of Period	$ 2,028,417			2,028,417
Accumulated Depreciation	$ 253,509			253,509
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,028,417
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 253,509
Operating Properties [Member] | 14200 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,396,794
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,960,376
Land and Improvements				1,699,632
Building and Improvements				4,657,538
Gross Amount Carried at End of Period	$ 6,357,170			6,357,170
Accumulated Depreciation	$ 658,529			658,529
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,357,170
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 658,529
Operating Properties [Member] | 1424 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				283,107
Initial Cost of Buildings				2,077,323
Costs Capitalized Subsequent to Acquisition				413,088
Land and Improvements				283,107
Building and Improvements				2,490,411
Gross Amount Carried at End of Period	$ 2,773,518			2,773,518
Accumulated Depreciation	$ 377,599			377,599
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,773,518
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 377,599
Operating Properties [Member] | 1428 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				367,446
Initial Cost of Buildings				1,952,453
Costs Capitalized Subsequent to Acquisition				461,116
Land and Improvements				367,446
Building and Improvements				2,413,568
Gross Amount Carried at End of Period	$ 2,781,014			2,781,014
Accumulated Depreciation	$ 323,367			323,367
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,781,014
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 323,367
Operating Properties [Member] | 14300 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,377,193
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,680,144
Land and Improvements				1,405,899
Building and Improvements				5,651,438
Gross Amount Carried at End of Period	$ 7,057,337			7,057,337
Accumulated Depreciation	$ 677,019			677,019
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,057,337
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 677,019
Operating Properties [Member] | 14400 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,830,419
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,240,317
Land and Improvements				1,861,540
Building and Improvements				7,209,196
Gross Amount Carried at End of Period	$ 9,070,736			9,070,736
Accumulated Depreciation	$ 1,763,306			1,763,306
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,070,736
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,763,306
Operating Properties [Member] | 15102 Sommermeyer St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				755,121
Initial Cost of Buildings				3,155,774
Costs Capitalized Subsequent to Acquisition				247,670
Land and Improvements				755,121
Building and Improvements				3,403,444
Gross Amount Carried at End of Period	$ 4,158,565			4,158,565
Accumulated Depreciation	$ 585,277			585,277
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,158,565
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 585,277
Operating Properties [Member] | 15150 Sommermeyer St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				418,580
Initial Cost of Buildings				1,564,587
Costs Capitalized Subsequent to Acquisition				246,785
Land and Improvements				418,580
Building and Improvements				1,811,372
Gross Amount Carried at End of Period	$ 2,229,952			2,229,952
Accumulated Depreciation	$ 320,777			320,777
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,229,952
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 320,777
Operating Properties [Member] | 16330 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,540,109
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				8,529,156
Land and Improvements				1,966,472
Building and Improvements				8,102,793
Gross Amount Carried at End of Period	$ 10,069,265			10,069,265
Accumulated Depreciation	$ 824,138			824,138
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,069,265
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 824,138
Operating Properties [Member] | 16420 West Hardy Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				438,853
Initial Cost of Buildings				3,030,396
Costs Capitalized Subsequent to Acquisition				932,746
Land and Improvements				438,853
Building and Improvements				3,963,142
Gross Amount Carried at End of Period	$ 4,401,995			4,401,995
Accumulated Depreciation	$ 1,923,396			1,923,396
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,401,995
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,923,396
Operating Properties [Member] | 16445 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				363,339
Initial Cost of Buildings				2,509,186
Costs Capitalized Subsequent to Acquisition				332,364
Land and Improvements				363,339
Building and Improvements				2,841,550
Gross Amount Carried at End of Period	$ 3,204,889			3,204,889
Accumulated Depreciation	$ 1,391,813			1,391,813
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,204,889
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,391,813
Operating Properties [Member] | 1646 Rankin Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				329,961
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,128,643
Land and Improvements				592,234
Building and Improvements				4,866,370
Gross Amount Carried at End of Period	$ 5,458,604			5,458,604
Accumulated Depreciation	$ 1,625,011			1,625,011
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,458,604
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,625,011
Operating Properties [Member] | 1655 Townhurst Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				197,226
Initial Cost of Buildings				935,036
Costs Capitalized Subsequent to Acquisition				528,775
Land and Improvements				197,226
Building and Improvements				1,463,811
Gross Amount Carried at End of Period	$ 1,661,037			1,661,037
Accumulated Depreciation	$ 331,956			331,956
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,661,037
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 331,956
Operating Properties [Member] | 16580 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				289,000
Initial Cost of Buildings				3,559,857
Costs Capitalized Subsequent to Acquisition				1,318,020
Land and Improvements				289,000
Building and Improvements				4,877,878
Gross Amount Carried at End of Period	$ 5,166,878			5,166,878
Accumulated Depreciation	$ 2,054,844			2,054,844
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,166,878
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,054,844
Operating Properties [Member] | 16602 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				284,403
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,462,115
Land and Improvements				503,779
Building and Improvements				5,242,739
Gross Amount Carried at End of Period	$ 5,746,518			5,746,518
Accumulated Depreciation	$ 1,629,717			1,629,717
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,746,518
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,629,717
Operating Properties [Member] | 16605 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				298,999
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,424,045
Land and Improvements				496,186
Building and Improvements				3,226,858
Gross Amount Carried at End of Period	$ 3,723,044			3,723,044
Accumulated Depreciation	$ 1,272,564			1,272,564
Date of Construction or Acquisition	2,002
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,723,044
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,272,564
Operating Properties [Member] | 1665 Townhurst Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				452,439
Initial Cost of Buildings				2,016,585
Costs Capitalized Subsequent to Acquisition				532,837
Land and Improvements				452,439
Building and Improvements				2,549,421
Gross Amount Carried at End of Period	$ 3,001,860			3,001,860
Accumulated Depreciation	$ 340,160			340,160
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,001,860
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 340,160
Operating Properties [Member] | 16680 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				311,952
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,714,436
Land and Improvements				492,869
Building and Improvements				3,533,519
Gross Amount Carried at End of Period	$ 4,026,388			4,026,388
Accumulated Depreciation	$ 863,726			863,726
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,026,388
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 863,726
Operating Properties [Member] | 16685 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				414,691
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,455,433
Land and Improvements				414,691
Building and Improvements				2,455,433
Gross Amount Carried at End of Period	$ 2,870,124			2,870,124
Accumulated Depreciation	$ 820,383			820,383
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,870,124
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 820,383
Operating Properties [Member] | 1755 Trans Central Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				293,534
Initial Cost of Buildings				3,036,269
Costs Capitalized Subsequent to Acquisition				1,254,342
Land and Improvements				306,147
Building and Improvements				4,277,998
Gross Amount Carried at End of Period	$ 4,584,145			4,584,145
Accumulated Depreciation	$ 1,661,466			1,661,466
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,584,145
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,661,466
Operating Properties [Member] | 4301 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				226,973
Initial Cost of Buildings				1,174,979
Costs Capitalized Subsequent to Acquisition				142,669
Land and Improvements				226,973
Building and Improvements				1,317,648
Gross Amount Carried at End of Period	$ 1,544,621			1,544,621
Accumulated Depreciation	$ 279,123			279,123
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,544,621
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 279,123
Operating Properties [Member] | 4401 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				244,240
Initial Cost of Buildings				1,412,622
Costs Capitalized Subsequent to Acquisition				164,426
Land and Improvements				244,240
Building and Improvements				1,577,048
Gross Amount Carried at End of Period	$ 1,821,288			1,821,288
Accumulated Depreciation	$ 322,106			322,106
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,821,288
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 322,106
Operating Properties [Member] | 4501 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				252,907
Initial Cost of Buildings				1,504,053
Costs Capitalized Subsequent to Acquisition				106,793
Land and Improvements				252,907
Building and Improvements				1,610,846
Gross Amount Carried at End of Period	$ 1,863,753			1,863,753
Accumulated Depreciation	$ 223,579			223,579
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,863,753
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 223,579
Operating Properties [Member] | 5200 N. Sam Houston Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,519,458
Initial Cost of Buildings				7,135,548
Costs Capitalized Subsequent to Acquisition				3,704,347
Land and Improvements				1,520,074
Building and Improvements				10,839,279
Gross Amount Carried at End of Period	$ 12,359,353			12,359,353
Accumulated Depreciation	$ 3,591,298			3,591,298
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,359,353
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,591,298
Operating Properties [Member] | 5250 N. Sam Houston Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				2,173,287
Initial Cost of Buildings				8,868,256
Costs Capitalized Subsequent to Acquisition				2,845,225
Land and Improvements				2,173,942
Building and Improvements				11,712,826
Gross Amount Carried at End of Period	$ 13,886,768			13,886,768
Accumulated Depreciation	$ 2,982,334			2,982,334
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,886,768
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,982,334
Operating Properties [Member] | 5500 N. Sam Houston Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,243,541
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,356,567
Land and Improvements				1,513,152
Building and Improvements				6,086,956
Gross Amount Carried at End of Period	$ 7,600,108			7,600,108
Accumulated Depreciation	$ 1,284,483			1,284,483
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,600,108
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,284,483
Operating Properties [Member] | 8017 Pinemont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				900,953
Initial Cost of Buildings				5,323,727
Costs Capitalized Subsequent to Acquisition				442,546
Land and Improvements				900,953
Building and Improvements				5,766,273
Gross Amount Carried at End of Period	$ 6,667,226			6,667,226
Accumulated Depreciation	$ 756,953			756,953
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,667,226
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 756,953
Operating Properties [Member] | 8272 El Rio Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				530,494
Initial Cost of Buildings				4,108,626
Costs Capitalized Subsequent to Acquisition				302,930
Land and Improvements				530,494
Building and Improvements				4,411,556
Gross Amount Carried at End of Period	$ 4,942,050			4,942,050
Accumulated Depreciation	$ 669,352			669,352
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,942,050
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 669,352
Operating Properties [Member] | 8282 El Rio Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				450,422
Initial Cost of Buildings				3,304,942
Costs Capitalized Subsequent to Acquisition				1,085,091
Land and Improvements				450,422
Building and Improvements				4,390,033
Gross Amount Carried at End of Period	$ 4,840,455			4,840,455
Accumulated Depreciation	$ 770,811			770,811
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,840,455
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 770,811
Operating Properties [Member] | 8301 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				4,515,862
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				26,996,308
Land and Improvements				7,083,514
Building and Improvements				24,428,656
Gross Amount Carried at End of Period	$ 31,512,170			31,512,170
Accumulated Depreciation	$ 6,261,457			6,261,457
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 31,512,170
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,261,457
Operating Properties [Member] | 8303 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				4,613,370
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				16,413,097
Land and Improvements				4,858,863
Building and Improvements				16,167,604
Gross Amount Carried at End of Period	$ 21,026,467			21,026,467
Accumulated Depreciation	$ 998,943			998,943
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,026,467
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 998,943
Operating Properties [Member] | 850 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				2,893,405
Initial Cost of Buildings				11,593,197
Costs Capitalized Subsequent to Acquisition				2,915,414
Land and Improvements				2,899,861
Building and Improvements				14,502,154
Gross Amount Carried at End of Period	$ 17,402,015			17,402,015
Accumulated Depreciation	$ 3,779,158			3,779,158
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 17,402,015
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,779,158
Operating Properties [Member] | 860 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,399,365
Initial Cost of Buildings				6,344,650
Costs Capitalized Subsequent to Acquisition				1,637,084
Land and Improvements				1,374,012
Building and Improvements				8,007,087
Gross Amount Carried at End of Period	$ 9,381,099			9,381,099
Accumulated Depreciation	$ 2,105,831			2,105,831
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,381,099
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,105,831
Operating Properties [Member] | 8801-19 & 8821-49 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				2,290,001
Initial Cost of Buildings				15,297,141
Costs Capitalized Subsequent to Acquisition				4,097,089
Land and Improvements				2,290,002
Building and Improvements				19,394,229
Gross Amount Carried at End of Period	$ 21,684,231			21,684,231
Accumulated Depreciation	$ 6,703,077			6,703,077
Date of Construction or Acquisition	2,000
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,684,231
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,703,077
Operating Properties [Member] | 8802-8824 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				2,774,995
Initial Cost of Buildings				6,364,767
Costs Capitalized Subsequent to Acquisition				2,050,563
Land and Improvements				2,775,021
Building and Improvements				8,415,303
Gross Amount Carried at End of Period	$ 11,190,324			11,190,324
Accumulated Depreciation	$ 2,583,641			2,583,641
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,190,324
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,583,641
Operating Properties [Member] | 8825-8839 N Sam Houston Pkwy [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				638,453
Initial Cost of Buildings				3,258,815
Costs Capitalized Subsequent to Acquisition				740,807
Land and Improvements				638,477
Building and Improvements				3,999,597
Gross Amount Carried at End of Period	$ 4,638,074			4,638,074
Accumulated Depreciation	$ 1,428,818			1,428,818
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,638,074
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,428,818
Operating Properties [Member] | 8850-8872 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				504,317
Initial Cost of Buildings				2,878,351
Costs Capitalized Subsequent to Acquisition				1,952,678
Land and Improvements				504,341
Building and Improvements				4,831,005
Gross Amount Carried at End of Period	$ 5,335,346			5,335,346
Accumulated Depreciation	$ 1,740,453			1,740,453
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,335,346
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,740,453
Operating Properties [Member] | 16200 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				1,748,348
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,342,218
Land and Improvements				2,120,319
Building and Improvements				8,970,247
Gross Amount Carried at End of Period	$ 11,090,566			11,090,566
Accumulated Depreciation	$ 1,448,476			1,448,476
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,090,566
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,448,476
Operating Properties [Member] | Cabot III UK1B01 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Isle of Man, UK
Encumbrances				0
Initial Cost of Land				11,888,058
Initial Cost of Buildings				35,003,668
Costs Capitalized Subsequent to Acquisition				(8,785,443)
Land and Improvements				9,702,442
Building and Improvements				28,403,841
Gross Amount Carried at End of Period	$ 38,106,283			38,106,283
Accumulated Depreciation	$ 3,449,692			3,449,692
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 38,106,283
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,449,692
Operating Properties [Member] | 1011 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Itasca, IL
Encumbrances				0
Initial Cost of Land				842,043
Initial Cost of Buildings				984,087
Costs Capitalized Subsequent to Acquisition				206,081
Land and Improvements				842,043
Building and Improvements				1,190,168
Gross Amount Carried at End of Period	$ 2,032,211			2,032,211
Accumulated Depreciation	$ 190,943			190,943
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,032,211
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 190,943
Operating Properties [Member] | 1035 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Itasca, IL
Encumbrances				0
Initial Cost of Land				875,172
Initial Cost of Buildings				2,071,051
Costs Capitalized Subsequent to Acquisition				125,154
Land and Improvements				875,172
Building and Improvements				2,196,206
Gross Amount Carried at End of Period	$ 3,071,378			3,071,378
Accumulated Depreciation	$ 291,896			291,896
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,071,378
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 291,896
Operating Properties [Member] | 1549 W Glenlake Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Itasca, IL
Encumbrances				0
Initial Cost of Land				1,339,627
Initial Cost of Buildings				3,763,288
Costs Capitalized Subsequent to Acquisition				197,452
Land and Improvements				1,339,627
Building and Improvements				3,960,739
Gross Amount Carried at End of Period	$ 5,300,366			5,300,366
Accumulated Depreciation	$ 559,334			559,334
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,300,366
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 559,334
Operating Properties [Member] | 901 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Itasca, IL
Encumbrances				0
Initial Cost of Land				866,378
Initial Cost of Buildings				2,112,616
Costs Capitalized Subsequent to Acquisition				47,981
Land and Improvements				866,378
Building and Improvements				2,160,597
Gross Amount Carried at End of Period	$ 3,026,975			3,026,975
Accumulated Depreciation	$ 272,326			272,326
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,026,975
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 272,326
Operating Properties [Member] | 925 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Itasca, IL
Encumbrances				0
Initial Cost of Land				945,251
Initial Cost of Buildings				2,010,181
Costs Capitalized Subsequent to Acquisition				47,544
Land and Improvements				945,251
Building and Improvements				2,057,725
Gross Amount Carried at End of Period	$ 3,002,976			3,002,976
Accumulated Depreciation	$ 257,674			257,674
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,002,976
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 257,674
Operating Properties [Member] | 8241 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Jessup, MD
Encumbrances				0
Initial Cost of Land				1,246,618
Initial Cost of Buildings				6,844,393
Costs Capitalized Subsequent to Acquisition				1,272,078
Land and Improvements				1,246,618
Building and Improvements				8,116,470
Gross Amount Carried at End of Period	$ 9,363,088			9,363,088
Accumulated Depreciation	$ 1,105,430			1,105,430
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,363,088
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,105,430
Operating Properties [Member] | 8242 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Jessup, MD
Encumbrances				0
Initial Cost of Land				1,488,746
Initial Cost of Buildings				9,072,440
Costs Capitalized Subsequent to Acquisition				1,482,236
Land and Improvements				1,488,746
Building and Improvements				10,554,676
Gross Amount Carried at End of Period	$ 12,043,422			12,043,422
Accumulated Depreciation	$ 1,556,327			1,556,327
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,043,422
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,556,327
Operating Properties [Member] | 8246 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Jessup, MD
Encumbrances				0
Initial Cost of Land				590,922
Initial Cost of Buildings				3,374,522
Costs Capitalized Subsequent to Acquisition				466,278
Land and Improvements				590,922
Building and Improvements				3,840,800
Gross Amount Carried at End of Period	$ 4,431,722			4,431,722
Accumulated Depreciation	$ 452,630			452,630
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,431,722
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 452,630
Operating Properties [Member] | 1305 Chastain Road NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Kennesaw, GA
Encumbrances				0
Initial Cost of Land				808,159
Initial Cost of Buildings				5,712,959
Costs Capitalized Subsequent to Acquisition				1,092,163
Land and Improvements				808,159
Building and Improvements				6,805,122
Gross Amount Carried at End of Period	$ 7,613,281			7,613,281
Accumulated Depreciation	$ 1,171,981			1,171,981
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,613,281
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,171,981
Operating Properties [Member] | 1325 Chastain Road NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Kennesaw, GA
Encumbrances				0
Initial Cost of Land				1,612,924
Initial Cost of Buildings				9,771,680
Costs Capitalized Subsequent to Acquisition				1,602,887
Land and Improvements				1,612,924
Building and Improvements				11,374,567
Gross Amount Carried at End of Period	$ 12,987,491			12,987,491
Accumulated Depreciation	$ 2,161,272			2,161,272
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,987,491
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,161,272
Operating Properties [Member] | 3600 Cobb International Bld NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Kennesaw, GA
Encumbrances				0
Initial Cost of Land				716,860
Initial Cost of Buildings				6,962,212
Costs Capitalized Subsequent to Acquisition				620,396
Land and Improvements				716,860
Building and Improvements				7,582,609
Gross Amount Carried at End of Period	$ 8,299,469			8,299,469
Accumulated Depreciation	$ 1,236,095			1,236,095
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,299,469
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,236,095
Operating Properties [Member] | Unit 1 Bear Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Kettering, UK
Encumbrances				0
Initial Cost of Land				10,849,890
Initial Cost of Buildings				36,219,855
Costs Capitalized Subsequent to Acquisition				(8,632,899)
Land and Improvements				8,855,141
Building and Improvements				29,581,705
Gross Amount Carried at End of Period	$ 38,436,846			38,436,846
Accumulated Depreciation	$ 3,855,300			3,855,300
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 38,436,846
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,855,300
Operating Properties [Member] | 650 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	King of Prussia, PA
Encumbrances				0
Initial Cost of Land				464,382
Initial Cost of Buildings				6,722,830
Costs Capitalized Subsequent to Acquisition				312,687
Land and Improvements				464,382
Building and Improvements				7,035,517
Gross Amount Carried at End of Period	$ 7,499,899			7,499,899
Accumulated Depreciation	$ 3,807,524			3,807,524
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,499,899
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,807,524
Operating Properties [Member] | 680 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	King of Prussia, PA
Encumbrances				0
Initial Cost of Land				952,361
Initial Cost of Buildings				6,722,830
Costs Capitalized Subsequent to Acquisition				7,218,586
Land and Improvements				952,361
Building and Improvements				13,941,416
Gross Amount Carried at End of Period	$ 14,893,777			14,893,777
Accumulated Depreciation	$ 7,812,014			7,812,014
Date of Construction or Acquisition	1,971
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,893,777
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 7,812,014
Operating Properties [Member] | 1770 Interstate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lakeland, FL
Encumbrances				0
Initial Cost of Land				650,000
Initial Cost of Buildings				5,444,220
Costs Capitalized Subsequent to Acquisition				436
Land and Improvements				650,000
Building and Improvements				5,444,656
Gross Amount Carried at End of Period	$ 6,094,656			6,094,656
Accumulated Depreciation	$ 746,367			746,367
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,094,656
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 746,367
Operating Properties [Member] | 5801 Columbia Park Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Landover,MD
Encumbrances				0
Initial Cost of Land				1,187,620
Initial Cost of Buildings				4,598,346
Costs Capitalized Subsequent to Acquisition				122,220
Land and Improvements				1,187,620
Building and Improvements				4,720,566
Gross Amount Carried at End of Period	$ 5,908,186			5,908,186
Accumulated Depreciation	$ 4,720,184			4,720,184
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,908,186
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,720,184
Operating Properties [Member] | 11425 State Highway 225 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				975,974
Initial Cost of Buildings				3,409,036
Costs Capitalized Subsequent to Acquisition				100,980
Land and Improvements				977,542
Building and Improvements				3,508,447
Gross Amount Carried at End of Period	$ 4,485,989			4,485,989
Accumulated Depreciation	$ 1,095,249			1,095,249
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,485,989
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,095,249
Operating Properties [Member] | 11503 State Highway 225 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				2,561,931
Initial Cost of Buildings				9,695,493
Costs Capitalized Subsequent to Acquisition				276,527
Land and Improvements				2,566,047
Building and Improvements				9,967,904
Gross Amount Carried at End of Period	$ 12,533,951			12,533,951
Accumulated Depreciation	$ 2,946,740			2,946,740
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,533,951
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,946,740
Operating Properties [Member] | 1701 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				4,063,262
Initial Cost of Buildings				18,719,368
Costs Capitalized Subsequent to Acquisition				339,178
Land and Improvements				4,063,262
Building and Improvements				19,058,546
Gross Amount Carried at End of Period	$ 23,121,808			23,121,808
Accumulated Depreciation	$ 1,326,243			1,326,243
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 23,121,808
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,326,243
Operating Properties [Member] | 1842 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				2,226,284
Initial Cost of Buildings				11,976,185
Costs Capitalized Subsequent to Acquisition				20,231
Land and Improvements				2,226,284
Building and Improvements				11,996,415
Gross Amount Carried at End of Period	$ 14,222,699			14,222,699
Accumulated Depreciation	$ 904,697			904,697
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,222,699
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 904,697
Operating Properties [Member] | 1902 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				2,369,095
Initial Cost of Buildings				14,119,020
Costs Capitalized Subsequent to Acquisition				1,131
Land and Improvements				2,369,095
Building and Improvements				14,120,151
Gross Amount Carried at End of Period	$ 16,489,246			16,489,246
Accumulated Depreciation	$ 1,118,950			1,118,950
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 16,489,246
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,118,950
Operating Properties [Member] | 640 S State Road 39 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lebanon,IN
Encumbrances				0
Initial Cost of Land				1,612,787
Initial Cost of Buildings				18,065,552
Costs Capitalized Subsequent to Acquisition				1,219,356
Land and Improvements				1,612,787
Building and Improvements				19,284,908
Gross Amount Carried at End of Period	$ 20,897,695			20,897,695
Accumulated Depreciation	$ 3,004,444			3,004,444
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,897,695
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,004,444
Operating Properties [Member] | 7528 Walker Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lehigh, PA
Encumbrances				0
Initial Cost of Land				893,441
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,712,528
Land and Improvements				779,330
Building and Improvements				5,826,639
Gross Amount Carried at End of Period	$ 6,605,969			6,605,969
Accumulated Depreciation	$ 2,282,849			2,282,849
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,605,969
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,282,849
Operating Properties [Member] | 8301 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lehigh, PA
Encumbrances				0
Initial Cost of Land				11,249,550
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				49,196,411
Land and Improvements				11,254,716
Building and Improvements				49,191,245
Gross Amount Carried at End of Period	$ 60,445,961			60,445,961
Accumulated Depreciation	$ 14,179,681			14,179,681
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 60,445,961
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 14,179,681
Operating Properties [Member] | 8500 Willard Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lehigh, PA
Encumbrances				0
Initial Cost of Land				6,398,815
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				33,823,153
Land and Improvements				11,355,974
Building and Improvements				28,865,994
Gross Amount Carried at End of Period	$ 40,221,968			40,221,968
Accumulated Depreciation	$ 6,248,053			6,248,053
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 40,221,968
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,248,053
Operating Properties [Member] | 8742 Congdon Hill Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lower Macungie, PA
Encumbrances				0
Initial Cost of Land				22,444,500
Initial Cost of Buildings				20,222,582
Costs Capitalized Subsequent to Acquisition				1,171,671
Land and Improvements				22,444,500
Building and Improvements				21,394,253
Gross Amount Carried at End of Period	$ 43,838,753			43,838,753
Accumulated Depreciation	$ 941,498			941,498
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 43,838,753
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 941,498
Operating Properties [Member] | 7533 Industrial Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lower Macungie, PA
Encumbrances				0
Initial Cost of Land				5,603,460
Initial Cost of Buildings				18,807,987
Costs Capitalized Subsequent to Acquisition				1,860,270
Land and Improvements				5,603,460
Building and Improvements				20,668,257
Gross Amount Carried at End of Period	$ 26,271,717			26,271,717
Accumulated Depreciation	$ 3,672,813			3,672,813
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 26,271,717
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,672,813
Operating Properties [Member] | 10 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				823,540
Initial Cost of Buildings				1,341,376
Costs Capitalized Subsequent to Acquisition				248,078
Land and Improvements				832,244
Building and Improvements				1,580,750
Gross Amount Carried at End of Period	$ 2,412,994			2,412,994
Accumulated Depreciation	$ 1,425,276			1,425,276
Date of Construction or Acquisition	2,003
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,412,994
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,425,276
Operating Properties [Member] | 100 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				1,320,625
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,423,695
Land and Improvements				1,891,736
Building and Improvements				6,852,584
Gross Amount Carried at End of Period	$ 8,744,320			8,744,320
Accumulated Depreciation	$ 3,942,208			3,942,208
Date of Construction or Acquisition	1,998
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,744,320
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,942,208
Operating Properties [Member] | 1001 Cedar Hollow Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				1,436,814
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				17,007,048
Land and Improvements				1,676,470
Building and Improvements				16,767,392
Gross Amount Carried at End of Period	$ 18,443,862			18,443,862
Accumulated Depreciation	$ 9,118,790			9,118,790
Date of Construction or Acquisition	1,998
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 18,443,862
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 9,118,790
Operating Properties [Member] | 12,14,16 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				130,689
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,329,277
Land and Improvements				128,767
Building and Improvements				1,331,199
Gross Amount Carried at End of Period	$ 1,459,966			1,459,966
Accumulated Depreciation	$ 1,195,890			1,195,890
Date of Construction or Acquisition	1,982
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,459,966
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,195,890
Operating Properties [Member] | 14 Lee Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				664,282
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,976,172
Land and Improvements				643,892
Building and Improvements				5,996,562
Gross Amount Carried at End of Period	$ 6,640,454			6,640,454
Accumulated Depreciation	$ 4,257,492			4,257,492
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,640,454
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,257,492
Operating Properties [Member] | 18 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				394,036
Initial Cost of Buildings				3,976,221
Costs Capitalized Subsequent to Acquisition				(1,229,185)
Land and Improvements				397,293
Building and Improvements				2,743,779
Gross Amount Carried at End of Period	$ 3,141,072			3,141,072
Accumulated Depreciation	$ 2,743,556			2,743,556
Date of Construction or Acquisition	1,980
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,141,072
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,743,556
Operating Properties [Member] | 311 Technology Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				397,131
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,710,751
Land and Improvements				397,948
Building and Improvements				2,709,934
Gross Amount Carried at End of Period	$ 3,107,882			3,107,882
Accumulated Depreciation	$ 2,514,676			2,514,676
Date of Construction or Acquisition	1,984
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,107,882
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,514,676
Operating Properties [Member] | 425 Old Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				3,847,501
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				45,862,512
Land and Improvements				9,953,208
Building and Improvements				39,756,805
Gross Amount Carried at End of Period	$ 49,710,013			49,710,013
Accumulated Depreciation	$ 3,688,031			3,688,031
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 49,710,013
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,688,031
Operating Properties [Member] | 50 Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				849,576
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				14,132,756
Land and Improvements				1,337,076
Building and Improvements				13,645,256
Gross Amount Carried at End of Period	$ 14,982,332			14,982,332
Accumulated Depreciation	$ 7,765,736			7,765,736
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,982,332
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 7,765,736
Operating Properties [Member] | 60 Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				865,424
Initial Cost of Buildings				9,285,000
Costs Capitalized Subsequent to Acquisition				1,476,443
Land and Improvements				884,974
Building and Improvements				10,741,893
Gross Amount Carried at End of Period	$ 11,626,867			11,626,867
Accumulated Depreciation	$ 6,133,475			6,133,475
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,626,867
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 6,133,475
Operating Properties [Member] | 600 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				2,013,750
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,308,073
Land and Improvements				2,695,891
Building and Improvements				8,625,932
Gross Amount Carried at End of Period	$ 11,321,823			11,321,823
Accumulated Depreciation	$ 4,702,546			4,702,546
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,321,823
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,702,546
Operating Properties [Member] | 700 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				2,013,750
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,147,731
Land and Improvements				2,683,149
Building and Improvements				8,478,332
Gross Amount Carried at End of Period	$ 11,161,481			11,161,481
Accumulated Depreciation	$ 4,633,824			4,633,824
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,161,481
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,633,824
Operating Properties [Member] | 1169 Canton Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Marietta, GA
Encumbrances				0
Initial Cost of Land				1,232,219
Initial Cost of Buildings				17,897,326
Costs Capitalized Subsequent to Acquisition				439,054
Land and Improvements				1,232,219
Building and Improvements				18,336,380
Gross Amount Carried at End of Period	$ 19,568,599			19,568,599
Accumulated Depreciation	$ 2,404,742			2,404,742
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 19,568,599
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,404,742
Operating Properties [Member] | 65 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Mauldin, SC
Encumbrances				0
Initial Cost of Land				557,174
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,605,186
Land and Improvements				506,318
Building and Improvements				2,656,042
Gross Amount Carried at End of Period	$ 3,162,360			3,162,360
Accumulated Depreciation	$ 469,821			469,821
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,162,360
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 469,821
Operating Properties [Member] | 75 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Mauldin, SC
Encumbrances				0
Initial Cost of Land				419,731
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,360,850
Land and Improvements				430,909
Building and Improvements				2,349,672
Gross Amount Carried at End of Period	$ 2,780,581			2,780,581
Accumulated Depreciation	$ 811,157			811,157
Date of Construction or Acquisition	2,003
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,780,581
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 811,157
Operating Properties [Member] | 126-132 Liberty Industrial Pkw [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	McDonough, GA
Encumbrances				0
Initial Cost of Land				600,666
Initial Cost of Buildings				4,184,131
Costs Capitalized Subsequent to Acquisition				573,605
Land and Improvements				600,666
Building and Improvements				4,757,735
Gross Amount Carried at End of Period	$ 5,358,401			5,358,401
Accumulated Depreciation	$ 1,011,099			1,011,099
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,358,401
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,011,099
Operating Properties [Member] | 95-115 Liberty Industrial Pkwy [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	McDonough, GA
Encumbrances				0
Initial Cost of Land				660,420
Initial Cost of Buildings				4,785,127
Costs Capitalized Subsequent to Acquisition				1,752,845
Land and Improvements				660,420
Building and Improvements				6,537,972
Gross Amount Carried at End of Period	$ 7,198,392			7,198,392
Accumulated Depreciation	$ 1,005,026			1,005,026
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,198,392
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,005,026
Operating Properties [Member] | 11150 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Medley, FL
Encumbrances				0
Initial Cost of Land				6,627,899
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				12,263,754
Land and Improvements				6,627,899
Building and Improvements				12,263,754
Gross Amount Carried at End of Period	$ 18,891,653			18,891,653
Accumulated Depreciation	$ 638,054			638,054
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 18,891,653
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 638,054
Operating Properties [Member] | 11401 NW 134th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Medley, FL
Encumbrances				0
Initial Cost of Land				5,558,619
Initial Cost of Buildings				17,678,237
Costs Capitalized Subsequent to Acquisition				980,129
Land and Improvements				5,558,619
Building and Improvements				18,658,366
Gross Amount Carried at End of Period	$ 24,216,985			24,216,985
Accumulated Depreciation	$ 2,703,407			2,703,407
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 24,216,985
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,703,407
Operating Properties [Member] | 11450 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Medley, FL
Encumbrances				0
Initial Cost of Land				1,623,293
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				11,366,493
Land and Improvements				3,919,238
Building and Improvements				9,070,548
Gross Amount Carried at End of Period	$ 12,989,786			12,989,786
Accumulated Depreciation	$ 661,827			661,827
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,989,786
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 661,827
Operating Properties [Member] | 456 International Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Minooka, IL
Encumbrances				0
Initial Cost of Land				3,862,683
Initial Cost of Buildings				14,357,981
Costs Capitalized Subsequent to Acquisition				4,629,086
Land and Improvements				3,862,683
Building and Improvements				18,987,067
Gross Amount Carried at End of Period	$ 22,849,750			22,849,750
Accumulated Depreciation	$ 2,656,638			2,656,638
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 22,849,750
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,656,638
Operating Properties [Member] | 21 S Middlesex Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Monroe Township, NJ
Encumbrances				0
Initial Cost of Land				2,097,170
Initial Cost of Buildings				9,715,401
Costs Capitalized Subsequent to Acquisition				562,568
Land and Improvements				2,097,170
Building and Improvements				10,277,969
Gross Amount Carried at End of Period	$ 12,375,139			12,375,139
Accumulated Depreciation	$ 1,693,385			1,693,385
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,375,139
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,693,385
Operating Properties [Member] | 4 S Middlesex Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Monroe Township, NJ
Encumbrances				0
Initial Cost of Land				2,263,153
Initial Cost of Buildings				10,261,759
Costs Capitalized Subsequent to Acquisition				1,026,738
Land and Improvements				2,263,153
Building and Improvements				11,288,497
Gross Amount Carried at End of Period	$ 13,551,650			13,551,650
Accumulated Depreciation	$ 1,657,916			1,657,916
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,551,650
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,657,916
Operating Properties [Member] | 250 Moonachie Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Moonachie, NJ
Encumbrances				0
Initial Cost of Land				10,435,430
Initial Cost of Buildings				7,272,539
Costs Capitalized Subsequent to Acquisition				131,978
Land and Improvements				10,435,430
Building and Improvements				7,404,517
Gross Amount Carried at End of Period	$ 17,839,947			17,839,947
Accumulated Depreciation	$ 96,404			96,404
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 17,839,947
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 96,404
Operating Properties [Member] | 230 Moonachie Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Moonachie, NJ
Encumbrances				0
Initial Cost of Land				4,031,058
Initial Cost of Buildings				2,775,467
Costs Capitalized Subsequent to Acquisition				45,946
Land and Improvements				4,031,058
Building and Improvements				2,821,413
Gross Amount Carried at End of Period	$ 6,852,471			6,852,471
Accumulated Depreciation	$ 36,357			36,357
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,852,471
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 36,357
Operating Properties [Member] | 22750 Cactus Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Moreno Valley, CA
Encumbrances				0
Initial Cost of Land				9,404,283
Initial Cost of Buildings				24,380,934
Costs Capitalized Subsequent to Acquisition				1,853,966
Land and Improvements				9,408,276
Building and Improvements				26,230,907
Gross Amount Carried at End of Period	$ 35,639,183			35,639,183
Accumulated Depreciation	$ 2,458,100			2,458,100
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 35,639,183
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,458,100
Operating Properties [Member] | 150 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				567,531
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				14,215,415
Land and Improvements				569,349
Building and Improvements				14,213,597
Gross Amount Carried at End of Period	$ 14,782,946			14,782,946
Accumulated Depreciation	$ 2,222,385			2,222,385
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,782,946
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,222,385
Operating Properties [Member] | 323 Park Knoll Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Morrisville, NC
Encumbrances				0
Initial Cost of Land				1,071,600
Initial Cost of Buildings				4,397,807
Costs Capitalized Subsequent to Acquisition				1,030,423
Land and Improvements				1,071,600
Building and Improvements				5,428,230
Gross Amount Carried at End of Period	$ 6,499,830			6,499,830
Accumulated Depreciation	$ 1,560,466			1,560,466
Date of Construction or Acquisition	2,010
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,499,830
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,560,466
Operating Properties [Member] | 324 Park Knoll Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Morrisville, NC
Encumbrances				0
Initial Cost of Land				1,449,092
Initial Cost of Buildings				4,424,932
Costs Capitalized Subsequent to Acquisition				330,650
Land and Improvements				1,449,450
Building and Improvements				4,755,224
Gross Amount Carried at End of Period	$ 6,204,674			6,204,674
Accumulated Depreciation	$ 1,398,371			1,398,371
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,204,674
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,398,371
Operating Properties [Member] | 619 Distribution Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Morrisville, NC
Encumbrances				0
Initial Cost of Land				1,031,430
Initial Cost of Buildings				5,655,167
Costs Capitalized Subsequent to Acquisition				769,814
Land and Improvements				1,031,685
Building and Improvements				6,424,726
Gross Amount Carried at End of Period	$ 7,456,411			7,456,411
Accumulated Depreciation	$ 1,793,552			1,793,552
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,456,411
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,793,552
Operating Properties [Member] | 1879 Lamont Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Odenton, MD
Encumbrances				0
Initial Cost of Land				1,976,000
Initial Cost of Buildings				8,099,579
Costs Capitalized Subsequent to Acquisition				2,067,394
Land and Improvements				2,011,030
Building and Improvements				10,131,943
Gross Amount Carried at End of Period	$ 12,142,973			12,142,973
Accumulated Depreciation	$ 3,497,401			3,497,401
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,142,973
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,497,401
Operating Properties [Member] | 350 Winmeyer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Odenton, MD
Encumbrances				0
Initial Cost of Land				1,778,400
Initial Cost of Buildings				7,289,165
Costs Capitalized Subsequent to Acquisition				1,702,845
Land and Improvements				1,809,927
Building and Improvements				8,960,483
Gross Amount Carried at End of Period	$ 10,770,410			10,770,410
Accumulated Depreciation	$ 2,799,293			2,799,293
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,770,410
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,799,293
Operating Properties [Member] | 4000 E Airport Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Ontario, CA
Encumbrances				0
Initial Cost of Land				2,686,533
Initial Cost of Buildings				10,125,772
Costs Capitalized Subsequent to Acquisition				658,692
Land and Improvements				2,686,533
Building and Improvements				10,784,464
Gross Amount Carried at End of Period	$ 13,470,997			13,470,997
Accumulated Depreciation	$ 1,483,811			1,483,811
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,470,997
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,483,811
Operating Properties [Member] | 1000 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				415,906
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,711,665
Land and Improvements				435,400
Building and Improvements				2,692,171
Gross Amount Carried at End of Period	$ 3,127,571			3,127,571
Accumulated Depreciation	$ 702,354			702,354
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,127,571
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 702,354
Operating Properties [Member] | 10003 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				680,312
Initial Cost of Buildings				2,120,754
Costs Capitalized Subsequent to Acquisition				1,351,516
Land and Improvements				680,312
Building and Improvements				3,472,270
Gross Amount Carried at End of Period	$ 4,152,582			4,152,582
Accumulated Depreciation	$ 1,492,523			1,492,523
Date of Construction or Acquisition	2,003
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,152,582
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,492,523
Operating Properties [Member] | 10511 & 10611 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				517,554
Initial Cost of Buildings				2,568,186
Costs Capitalized Subsequent to Acquisition				701,878
Land and Improvements				522,991
Building and Improvements				3,264,627
Gross Amount Carried at End of Period	$ 3,787,618			3,787,618
Accumulated Depreciation	$ 1,701,375			1,701,375
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,787,618
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,701,375
Operating Properties [Member] | 10771 Palm Bay Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				664,605
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,515,852
Land and Improvements				685,383
Building and Improvements				2,495,074
Gross Amount Carried at End of Period	$ 3,180,457			3,180,457
Accumulated Depreciation	$ 969,898			969,898
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,180,457
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 969,898
Operating Properties [Member] | 1090 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				878,320
Initial Cost of Buildings				2,558,833
Costs Capitalized Subsequent to Acquisition				3,837,116
Land and Improvements				878,320
Building and Improvements				6,395,949
Gross Amount Carried at End of Period	$ 7,274,269			7,274,269
Accumulated Depreciation	$ 1,496,145			1,496,145
Date of Construction or Acquisition	2,003
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,274,269
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,496,145
Operating Properties [Member] | 1600-1650 Central Florida Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				518,043
Initial Cost of Buildings				2,561,938
Costs Capitalized Subsequent to Acquisition				966,443
Land and Improvements				518,043
Building and Improvements				3,528,381
Gross Amount Carried at End of Period	$ 4,046,424			4,046,424
Accumulated Depreciation	$ 1,887,708			1,887,708
Date of Construction or Acquisition	1,962
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,046,424
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,887,708
Operating Properties [Member] | 1902 Cypress Lake Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				523,512
Initial Cost of Buildings				3,191,790
Costs Capitalized Subsequent to Acquisition				1,529,900
Land and Improvements				538,512
Building and Improvements				4,706,690
Gross Amount Carried at End of Period	$ 5,245,202			5,245,202
Accumulated Depreciation	$ 2,379,793			2,379,793
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,245,202
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,379,793
Operating Properties [Member] | 2000 Park Oaks Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				913,201
Initial Cost of Buildings				6,818,610
Costs Capitalized Subsequent to Acquisition				993,925
Land and Improvements				913,201
Building and Improvements				7,812,535
Gross Amount Carried at End of Period	$ 8,725,736			8,725,736
Accumulated Depreciation	$ 1,131,776			1,131,776
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,725,736
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,131,776
Operating Properties [Member] | 2202 Taft-Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,283,713
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,315,647
Land and Improvements				1,283,713
Building and Improvements				7,315,647
Gross Amount Carried at End of Period	$ 8,599,360			8,599,360
Accumulated Depreciation	$ 3,147,459			3,147,459
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,599,360
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,147,459
Operating Properties [Member] | 2212 Taft Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				838,853
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,084,873
Land and Improvements				767,953
Building and Improvements				4,155,773
Gross Amount Carried at End of Period	$ 4,923,726			4,923,726
Accumulated Depreciation	$ 1,408,619			1,408,619
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,923,726
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,408,619
Operating Properties [Member] | 2256 Taft-Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				467,296
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,856,883
Land and Improvements				825,673
Building and Improvements				2,498,506
Gross Amount Carried at End of Period	$ 3,324,179			3,324,179
Accumulated Depreciation	$ 965,372			965,372
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,324,179
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 965,372
Operating Properties [Member] | 2351 Investors Row [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				2,261,924
Initial Cost of Buildings				7,496,249
Costs Capitalized Subsequent to Acquisition				1,892,529
Land and Improvements				2,271,785
Building and Improvements				9,378,917
Gross Amount Carried at End of Period	$ 11,650,702			11,650,702
Accumulated Depreciation	$ 3,062,843			3,062,843
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,650,702
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,062,843
Operating Properties [Member] | 2400 South Lake Orange Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				385,964
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,247,268
Land and Improvements				642,427
Building and Improvements				2,990,805
Gross Amount Carried at End of Period	$ 3,633,232			3,633,232
Accumulated Depreciation	$ 1,441,537			1,441,537
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,633,232
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,441,537
Operating Properties [Member] | 2412 Sand Lake Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,236,819
Initial Cost of Buildings				3,243,314
Costs Capitalized Subsequent to Acquisition				4,569,481
Land and Improvements				1,244,667
Building and Improvements				7,804,947
Gross Amount Carried at End of Period	$ 9,049,614			9,049,614
Accumulated Depreciation	$ 1,078,475			1,078,475
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,049,614
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,078,475
Operating Properties [Member] | 2416 Lake Orange Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				535,964
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,817,081
Land and Improvements				704,800
Building and Improvements				3,648,245
Gross Amount Carried at End of Period	$ 4,353,045			4,353,045
Accumulated Depreciation	$ 1,848,025			1,848,025
Date of Construction or Acquisition	2,002
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,353,045
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,848,025
Operating Properties [Member] | 6200 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,435,301
Initial Cost of Buildings				6,174,642
Costs Capitalized Subsequent to Acquisition				701,669
Land and Improvements				1,435,301
Building and Improvements				6,876,311
Gross Amount Carried at End of Period	$ 8,311,612			8,311,612
Accumulated Depreciation	$ 2,236,259			2,236,259
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,311,612
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,236,259
Operating Properties [Member] | 6989 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				903,701
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,673,463
Land and Improvements				925,671
Building and Improvements				5,651,493
Gross Amount Carried at End of Period	$ 6,577,164			6,577,164
Accumulated Depreciation	$ 2,321,511			2,321,511
Date of Construction or Acquisition	2,001
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,577,164
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,321,511
Operating Properties [Member] | 6918 Presidents Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				872,550
Initial Cost of Buildings				2,526,043
Costs Capitalized Subsequent to Acquisition				738,036
Land and Improvements				872,550
Building and Improvements				3,264,079
Gross Amount Carried at End of Period	$ 4,136,629			4,136,629
Accumulated Depreciation	$ 407,627			407,627
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,136,629
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 407,627
Operating Properties [Member] | 6923 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				903,701
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,394,043
Land and Improvements				830,953
Building and Improvements				3,466,791
Gross Amount Carried at End of Period	$ 4,297,744			4,297,744
Accumulated Depreciation	$ 911,447			911,447
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,297,744
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 911,447
Operating Properties [Member] | 7022 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,443,510
Initial Cost of Buildings				6,775,194
Costs Capitalized Subsequent to Acquisition				666,574
Land and Improvements				1,457,286
Building and Improvements				7,427,993
Gross Amount Carried at End of Period	$ 8,885,279			8,885,279
Accumulated Depreciation	$ 2,162,331			2,162,331
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,885,279
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,162,331
Operating Properties [Member] | 7100 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,431,489
Initial Cost of Buildings				8,002,539
Costs Capitalized Subsequent to Acquisition				1,221,160
Land and Improvements				1,445,807
Building and Improvements				9,209,381
Gross Amount Carried at End of Period	$ 10,655,188			10,655,188
Accumulated Depreciation	$ 2,510,571			2,510,571
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,655,188
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,510,571
Operating Properties [Member] | 7101 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,553,537
Initial Cost of Buildings				5,702,243
Costs Capitalized Subsequent to Acquisition				635,492
Land and Improvements				1,570,863
Building and Improvements				6,320,409
Gross Amount Carried at End of Period	$ 7,891,272			7,891,272
Accumulated Depreciation	$ 1,789,479			1,789,479
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,891,272
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,789,479
Operating Properties [Member] | 7315 Kingspointe Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				1,931,697
Initial Cost of Buildings				6,388,203
Costs Capitalized Subsequent to Acquisition				2,921,391
Land and Improvements				1,932,004
Building and Improvements				9,309,287
Gross Amount Carried at End of Period	$ 11,241,291			11,241,291
Accumulated Depreciation	$ 3,939,705			3,939,705
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,241,291
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,939,705
Operating Properties [Member] | 851 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				332,992
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,800,846
Land and Improvements				373,500
Building and Improvements				2,760,338
Gross Amount Carried at End of Period	$ 3,133,838			3,133,838
Accumulated Depreciation	$ 717,909			717,909
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,133,838
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 717,909
Operating Properties [Member] | 950 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				443,989
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,817,379
Land and Improvements				464,800
Building and Improvements				2,796,568
Gross Amount Carried at End of Period	$ 3,261,368			3,261,368
Accumulated Depreciation	$ 664,304			664,304
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,261,368
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 664,304
Operating Properties [Member] | 29 Liberty Square [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				165,363
Initial Cost of Buildings				1,139,928
Costs Capitalized Subsequent to Acquisition				25,834
Land and Improvements				168,913
Building and Improvements				1,162,211
Gross Amount Carried at End of Period	$ 1,331,124			1,331,124
Accumulated Depreciation	$ 43,922			43,922
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,331,124
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 43,922
Operating Properties [Member] | 9550 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				574,831
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,690,726
Land and Improvements				587,319
Building and Improvements				2,678,238
Gross Amount Carried at End of Period	$ 3,265,557			3,265,557
Accumulated Depreciation	$ 1,422,420			1,422,420
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,265,557
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,422,420
Operating Properties [Member] | 3535 Gravel Springs Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Buford, GA
Encumbrances				0
Initial Cost of Land				2,807,020
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,348,803
Land and Improvements				3,077,350
Building and Improvements				9,078,473
Gross Amount Carried at End of Period	$ 12,155,823			12,155,823
Accumulated Depreciation	$ 85,572			85,572
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,155,823
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 85,572
Operating Properties [Member] | 9700 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Orlando, FL
Encumbrances				0
Initial Cost of Land				252,850
Initial Cost of Buildings				1,297,923
Costs Capitalized Subsequent to Acquisition				185,218
Land and Improvements				252,850
Building and Improvements				1,483,141
Gross Amount Carried at End of Period	$ 1,735,991			1,735,991
Accumulated Depreciation	$ 744,969			744,969
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,735,991
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 744,969
Operating Properties [Member] | 1 Crescent Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				567,280
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				15,193,253
Land and Improvements				347,892
Building and Improvements				15,412,641
Gross Amount Carried at End of Period	$ 15,760,533			15,760,533
Accumulated Depreciation	$ 4,588,553			4,588,553
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,760,533
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,588,553
Operating Properties [Member] | 201 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				243,905
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				22,536,140
Land and Improvements				449,013
Building and Improvements				22,331,032
Gross Amount Carried at End of Period	$ 22,780,045			22,780,045
Accumulated Depreciation	$ 2,045,156			2,045,156
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 22,780,045
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,045,156
Operating Properties [Member] | 351 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				359,864
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				16,741,665
Land and Improvements				367,016
Building and Improvements				16,734,513
Gross Amount Carried at End of Period	$ 17,101,529			17,101,529
Accumulated Depreciation	$ 468,293			468,293
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 17,101,529
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 468,293
Operating Properties [Member] | 3 Crescent Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				214,726
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				24,170,214
Land and Improvements				417,823
Building and Improvements				23,967,117
Gross Amount Carried at End of Period	$ 24,384,940			24,384,940
Accumulated Depreciation	$ 4,631,085			4,631,085
Date of Construction or Acquisition	2,008
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 24,384,940
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,631,085
Operating Properties [Member] | 4000 S 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				1,255,507
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,817,040
Land and Improvements				1,142,358
Building and Improvements				10,930,189
Gross Amount Carried at End of Period	$ 12,072,547			12,072,547
Accumulated Depreciation	$ 789,639			789,639
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,072,547
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 789,639
Operating Properties [Member] | 4020 S 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				51,784
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,165,713
Land and Improvements				616,467
Building and Improvements				6,601,030
Gross Amount Carried at End of Period	$ 7,217,497			7,217,497
Accumulated Depreciation	$ 1,042,441			1,042,441
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,217,497
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,042,441
Operating Properties [Member] | 4050 S 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				46,301
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,164,435
Land and Improvements				616,670
Building and Improvements				6,594,066
Gross Amount Carried at End of Period	$ 7,210,736			7,210,736
Accumulated Depreciation	$ 1,278,766			1,278,766
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,210,736
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,278,766
Operating Properties [Member] | 4300 South 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				402,673
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				34,857,088
Land and Improvements				413,030
Building and Improvements				34,846,731
Gross Amount Carried at End of Period	$ 35,259,761			35,259,761
Accumulated Depreciation	$ 7,526,028			7,526,028
Date of Construction or Acquisition	2,008
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 35,259,761
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 7,526,028
Operating Properties [Member] | 4751 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				992,965
Initial Cost of Buildings				331,924
Costs Capitalized Subsequent to Acquisition				7,830,302
Land and Improvements				613,248
Building and Improvements				8,541,943
Gross Amount Carried at End of Period	$ 9,155,191			9,155,191
Accumulated Depreciation	$ 3,262,455			3,262,455
Date of Construction or Acquisition	2,003
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,155,191
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,262,455
Operating Properties [Member] | 4775 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				891,892
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,579,310
Land and Improvements				366,982
Building and Improvements				6,104,220
Gross Amount Carried at End of Period	$ 6,471,202			6,471,202
Accumulated Depreciation	$ 1,639,085			1,639,085
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,471,202
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,639,085
Operating Properties [Member] | 8th & Walnut Streets [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				38,446,743
Initial Cost of Land				734,275
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				45,400,360
Land and Improvements				0
Building and Improvements				46,134,635
Gross Amount Carried at End of Period	$ 46,134,635			46,134,635
Accumulated Depreciation	$ 4,515,020			4,515,020
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 46,134,635
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,515,020
Operating Properties [Member] | 2626 South 7th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Phoenix, AZ
Encumbrances				0
Initial Cost of Land				2,519,510
Initial Cost of Buildings				3,798,560
Costs Capitalized Subsequent to Acquisition				3,685,037
Land and Improvements				2,519,510
Building and Improvements				7,483,597
Gross Amount Carried at End of Period	$ 10,003,107			10,003,107
Accumulated Depreciation	$ 1,336,897			1,336,897
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,003,107
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,336,897
Operating Properties [Member] | 563 South 63rd Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Phoenix, AZ
Encumbrances				0
Initial Cost of Land				5,523,427
Initial Cost of Buildings				14,581,705
Costs Capitalized Subsequent to Acquisition				12,213,826
Land and Improvements				5,636,070
Building and Improvements				26,682,888
Gross Amount Carried at End of Period	$ 32,318,958			32,318,958
Accumulated Depreciation	$ 3,051,216			3,051,216
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 32,318,958
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,051,216
Operating Properties [Member] | 1000 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				706,660
Initial Cost of Buildings				5,894,330
Costs Capitalized Subsequent to Acquisition				221,055
Land and Improvements				706,660
Building and Improvements				6,115,386
Gross Amount Carried at End of Period	$ 6,822,046			6,822,046
Accumulated Depreciation	$ 828,306			828,306
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,822,046
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 828,306
Operating Properties [Member] | 1901 10th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				555,168
Initial Cost of Buildings				6,401,789
Costs Capitalized Subsequent to Acquisition				618,010
Land and Improvements				555,168
Building and Improvements				7,019,799
Gross Amount Carried at End of Period	$ 7,574,967			7,574,967
Accumulated Depreciation	$ 1,037,479			1,037,479
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,574,967
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,037,479
Operating Properties [Member] | 1909 10th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				551,706
Initial Cost of Buildings				5,797,440
Costs Capitalized Subsequent to Acquisition				328,067
Land and Improvements				551,706
Building and Improvements				6,125,507
Gross Amount Carried at End of Period	$ 6,677,213			6,677,213
Accumulated Depreciation	$ 880,200			880,200
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,677,213
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 880,200
Operating Properties [Member] | 3605 East Plano Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				1,047,996
Initial Cost of Buildings				9,218,748
Costs Capitalized Subsequent to Acquisition				1,970,974
Land and Improvements				1,047,996
Building and Improvements				11,189,721
Gross Amount Carried at End of Period	$ 12,237,717			12,237,717
Accumulated Depreciation	$ 1,820,188			1,820,188
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,237,717
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,820,188
Operating Properties [Member] | 3701 East Plano Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				877,564
Initial Cost of Buildings				7,460,686
Costs Capitalized Subsequent to Acquisition				773,494
Land and Improvements				877,564
Building and Improvements				8,234,179
Gross Amount Carried at End of Period	$ 9,111,743			9,111,743
Accumulated Depreciation	$ 1,150,031			1,150,031
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,111,743
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,150,031
Operating Properties [Member] | 800 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				580,456
Initial Cost of Buildings				5,681,283
Costs Capitalized Subsequent to Acquisition				1,595,423
Land and Improvements				580,456
Building and Improvements				7,276,706
Gross Amount Carried at End of Period	$ 7,857,162			7,857,162
Accumulated Depreciation	$ 973,045			973,045
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,857,162
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 973,045
Operating Properties [Member] | 900 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plano, TX
Encumbrances				0
Initial Cost of Land				723,534
Initial Cost of Buildings				6,004,923
Costs Capitalized Subsequent to Acquisition				378,359
Land and Improvements				723,534
Building and Improvements				6,383,282
Gross Amount Carried at End of Period	$ 7,106,816			7,106,816
Accumulated Depreciation	$ 989,893			989,893
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,106,816
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 989,893
Operating Properties [Member] | 9801 80th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pleasant Prairie, WI
Encumbrances				0
Initial Cost of Land				1,692,077
Initial Cost of Buildings				7,934,794
Costs Capitalized Subsequent to Acquisition				58,937
Land and Improvements				1,689,726
Building and Improvements				7,996,082
Gross Amount Carried at End of Period	$ 9,685,808			9,685,808
Accumulated Depreciation	$ 3,807,978			3,807,978
Date of Construction or Acquisition	1,994
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,685,808
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,807,978
Operating Properties [Member] | 14630-14650 28th Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plymouth, MN
Encumbrances				0
Initial Cost of Land				198,205
Initial Cost of Buildings				1,793,422
Costs Capitalized Subsequent to Acquisition				1,097,124
Land and Improvements				198,205
Building and Improvements				2,890,545
Gross Amount Carried at End of Period	$ 3,088,750			3,088,750
Accumulated Depreciation	$ 1,499,797			1,499,797
Date of Construction or Acquisition	1,978
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,088,750
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,499,797
Operating Properties [Member] | 2920 Northwest Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plymouth, MN
Encumbrances				0
Initial Cost of Land				392,026
Initial Cost of Buildings				3,433,678
Costs Capitalized Subsequent to Acquisition				773,681
Land and Improvements				384,235
Building and Improvements				4,215,150
Gross Amount Carried at End of Period	$ 4,599,385			4,599,385
Accumulated Depreciation	$ 2,058,675			2,058,675
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,599,385
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,058,675
Operating Properties [Member] | 5905 Trenton Lane North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plymouth, MN
Encumbrances				0
Initial Cost of Land				1,616,360
Initial Cost of Buildings				4,487,462
Costs Capitalized Subsequent to Acquisition				735,642
Land and Improvements				1,616,360
Building and Improvements				5,223,103
Gross Amount Carried at End of Period	$ 6,839,463			6,839,463
Accumulated Depreciation	$ 865,378			865,378
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,839,463
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 865,378
Operating Properties [Member] | 6055 Nathan Lane North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Plymouth, MN
Encumbrances				0
Initial Cost of Land				1,327,017
Initial Cost of Buildings				4,527,404
Costs Capitalized Subsequent to Acquisition				826,105
Land and Improvements				1,327,017
Building and Improvements				5,353,509
Gross Amount Carried at End of Period	$ 6,680,526			6,680,526
Accumulated Depreciation	$ 837,746			837,746
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,680,526
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 837,746
Operating Properties [Member] | 1400 SW 6th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				1,157,049
Initial Cost of Buildings				4,620,956
Costs Capitalized Subsequent to Acquisition				1,351,035
Land and Improvements				1,157,049
Building and Improvements				5,971,991
Gross Amount Carried at End of Period	$ 7,129,040			7,129,040
Accumulated Depreciation	$ 2,947,077			2,947,077
Date of Construction or Acquisition	1,986
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,129,040
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,947,077
Operating Properties [Member] | 1405 SW 6th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				392,138
Initial Cost of Buildings				1,565,787
Costs Capitalized Subsequent to Acquisition				443,631
Land and Improvements				392,138
Building and Improvements				2,009,419
Gross Amount Carried at End of Period	$ 2,401,557			2,401,557
Accumulated Depreciation	$ 1,046,464			1,046,464
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,401,557
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,046,464
Operating Properties [Member] | 1500 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				972,232
Initial Cost of Buildings				3,892,085
Costs Capitalized Subsequent to Acquisition				1,423,097
Land and Improvements				972,232
Building and Improvements				5,315,182
Gross Amount Carried at End of Period	$ 6,287,414			6,287,414
Accumulated Depreciation	$ 2,445,184			2,445,184
Date of Construction or Acquisition	1,957
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,287,414
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,445,184
Operating Properties [Member] | 1501 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				203,247
Initial Cost of Buildings				811,093
Costs Capitalized Subsequent to Acquisition				369,074
Land and Improvements				203,247
Building and Improvements				1,180,168
Gross Amount Carried at End of Period	$ 1,383,415			1,383,415
Accumulated Depreciation	$ 612,674			612,674
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,383,415
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 612,674
Operating Properties [Member] | 1601 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				203,247
Initial Cost of Buildings				811,093
Costs Capitalized Subsequent to Acquisition				208,337
Land and Improvements				203,247
Building and Improvements				1,019,431
Gross Amount Carried at End of Period	$ 1,222,678			1,222,678
Accumulated Depreciation	$ 476,637			476,637
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,222,678
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 476,637
Operating Properties [Member] | 1651 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				203,247
Initial Cost of Buildings				811,093
Costs Capitalized Subsequent to Acquisition				154,527
Land and Improvements				203,247
Building and Improvements				965,621
Gross Amount Carried at End of Period	$ 1,168,868			1,168,868
Accumulated Depreciation	$ 450,544			450,544
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,168,868
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 450,544
Operating Properties [Member] | 2201-2215 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				1,120,328
Initial Cost of Buildings				3,427,358
Costs Capitalized Subsequent to Acquisition				131,858
Land and Improvements				1,120,328
Building and Improvements				3,559,216
Gross Amount Carried at End of Period	$ 4,679,544			4,679,544
Accumulated Depreciation	$ 484,217			484,217
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,679,544
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 484,217
Operating Properties [Member] | 2250-2270 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				993,015
Initial Cost of Buildings				2,423,174
Costs Capitalized Subsequent to Acquisition				135,867
Land and Improvements				993,015
Building and Improvements				2,559,041
Gross Amount Carried at End of Period	$ 3,552,056			3,552,056
Accumulated Depreciation	$ 381,687			381,687
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,552,056
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 381,687
Operating Properties [Member] | 2280-2300 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				906,947
Initial Cost of Buildings				2,157,802
Costs Capitalized Subsequent to Acquisition				189,366
Land and Improvements				906,947
Building and Improvements				2,347,169
Gross Amount Carried at End of Period	$ 3,254,116			3,254,116
Accumulated Depreciation	$ 377,549			377,549
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,254,116
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 377,549
Operating Properties [Member] | 2301-2329 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				1,268,707
Initial Cost of Buildings				3,079,811
Costs Capitalized Subsequent to Acquisition				124,704
Land and Improvements				1,268,707
Building and Improvements				3,204,515
Gross Amount Carried at End of Period	$ 4,473,222			4,473,222
Accumulated Depreciation	$ 437,326			437,326
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,473,222
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 437,326
Operating Properties [Member] | 3000 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				1,087,554
Initial Cost of Buildings				2,897,117
Costs Capitalized Subsequent to Acquisition				156,810
Land and Improvements				1,087,554
Building and Improvements				3,053,927
Gross Amount Carried at End of Period	$ 4,141,481			4,141,481
Accumulated Depreciation	$ 466,741			466,741
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,141,481
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 466,741
Operating Properties [Member] | 3001-3037 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				1,548,542
Initial Cost of Buildings				3,512,041
Costs Capitalized Subsequent to Acquisition				338,715
Land and Improvements				1,548,542
Building and Improvements				3,850,757
Gross Amount Carried at End of Period	$ 5,399,299			5,399,299
Accumulated Depreciation	$ 663,071			663,071
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,399,299
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 663,071
Operating Properties [Member] | 3012-3050 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				1,112,781
Initial Cost of Buildings				2,763,862
Costs Capitalized Subsequent to Acquisition				225,157
Land and Improvements				1,112,781
Building and Improvements				2,989,018
Gross Amount Carried at End of Period	$ 4,101,799			4,101,799
Accumulated Depreciation	$ 478,959			478,959
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,101,799
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 478,959
Operating Properties [Member] | 595 SW 13th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				359,933
Initial Cost of Buildings				1,437,116
Costs Capitalized Subsequent to Acquisition				720,423
Land and Improvements				359,933
Building and Improvements				2,157,539
Gross Amount Carried at End of Period	$ 2,517,472			2,517,472
Accumulated Depreciation	$ 1,259,729			1,259,729
Date of Construction or Acquisition	1,984
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,517,472
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,259,729
Operating Properties [Member] | 601 SW 13th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				164,413
Initial Cost of Buildings				655,933
Costs Capitalized Subsequent to Acquisition				279,401
Land and Improvements				164,413
Building and Improvements				935,334
Gross Amount Carried at End of Period	$ 1,099,747			1,099,747
Accumulated Depreciation	$ 536,076			536,076
Date of Construction or Acquisition	1,984
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,099,747
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 536,076
Operating Properties [Member] | 605 SW 16th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Pompano Beach, FL
Encumbrances				0
Initial Cost of Land				310,778
Initial Cost of Buildings				1,238,324
Costs Capitalized Subsequent to Acquisition				294,980
Land and Improvements				310,178
Building and Improvements				1,533,904
Gross Amount Carried at End of Period	$ 1,844,082			1,844,082
Accumulated Depreciation	$ 672,829			672,829
Date of Construction or Acquisition	1,965
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,844,082
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 672,829
Operating Properties [Member] | 2459 Almond Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Redlands, CA
Initial Cost of Land				3,810,171
Initial Cost of Buildings				11,979,923
Costs Capitalized Subsequent to Acquisition				140,915
Land and Improvements				3,810,171
Building and Improvements				12,120,838
Gross Amount Carried at End of Period	$ 15,931,009			15,931,009
Accumulated Depreciation	$ 112,006			112,006
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,931,009
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 112,006
Operating Properties [Member] | 1221 N Alder Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rialto, CA
Initial Cost of Land				17,280,833
Initial Cost of Buildings				72,740,859
Costs Capitalized Subsequent to Acquisition				5,825
Land and Improvements				17,280,833
Building and Improvements				72,746,684
Gross Amount Carried at End of Period	$ 90,027,517			90,027,517
Accumulated Depreciation	$ 14,606			14,606
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 90,027,517
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 14,606
Operating Properties [Member] | 1920 West Baseline Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rialto, CA
Encumbrances				0
Initial Cost of Land				9,361,943
Initial Cost of Buildings				17,970,709
Costs Capitalized Subsequent to Acquisition				454,600
Land and Improvements				9,411,621
Building and Improvements				18,375,631
Gross Amount Carried at End of Period	$ 27,787,252			27,787,252
Accumulated Depreciation	$ 1,430,709			1,430,709
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 27,787,252
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,430,709
Operating Properties [Member] | 301 Hill Carter Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				659,456
Initial Cost of Buildings				4,836,010
Costs Capitalized Subsequent to Acquisition				160,298
Land and Improvements				659,456
Building and Improvements				4,996,308
Gross Amount Carried at End of Period	$ 5,655,764			5,655,764
Accumulated Depreciation	$ 2,886,300			2,886,300
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,655,764
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,886,300
Operating Properties [Member] | 4101-4127 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				310,854
Initial Cost of Buildings				2,279,597
Costs Capitalized Subsequent to Acquisition				1,910,263
Land and Improvements				310,854
Building and Improvements				4,189,860
Gross Amount Carried at End of Period	$ 4,500,714			4,500,714
Accumulated Depreciation	$ 1,969,050			1,969,050
Date of Construction or Acquisition	1,973
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,500,714
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,969,050
Operating Properties [Member] | 4201-4261 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				693,203
Initial Cost of Buildings				5,083,493
Costs Capitalized Subsequent to Acquisition				2,158,077
Land and Improvements				693,203
Building and Improvements				7,241,570
Gross Amount Carried at End of Period	$ 7,934,773			7,934,773
Accumulated Depreciation	$ 4,258,125			4,258,125
Date of Construction or Acquisition	1,975
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,934,773
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,258,125
Operating Properties [Member] | 4263-4299 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				256,203
Initial Cost of Buildings				2,549,649
Costs Capitalized Subsequent to Acquisition				3,110,924
Land and Improvements				256,203
Building and Improvements				5,660,573
Gross Amount Carried at End of Period	$ 5,916,776			5,916,776
Accumulated Depreciation	$ 2,854,983			2,854,983
Date of Construction or Acquisition	1,976
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,916,776
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,854,983
Operating Properties [Member] | 4263F-N. Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				91,476
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,969,181
Land and Improvements				91,599
Building and Improvements				1,969,058
Gross Amount Carried at End of Period	$ 2,060,657			2,060,657
Accumulated Depreciation	$ 1,069,559			1,069,559
Date of Construction or Acquisition	1,975
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,060,657
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,069,559
Operating Properties [Member] | 4301-4335 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				223,696
Initial Cost of Buildings				1,640,435
Costs Capitalized Subsequent to Acquisition				2,945,635
Land and Improvements				223,696
Building and Improvements				4,586,070
Gross Amount Carried at End of Period	$ 4,809,766			4,809,766
Accumulated Depreciation	$ 2,149,270			2,149,270
Date of Construction or Acquisition	1,978
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,809,766
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,149,270
Operating Properties [Member] | 4337-4379 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				325,303
Initial Cost of Buildings				2,385,557
Costs Capitalized Subsequent to Acquisition				1,426,384
Land and Improvements				325,303
Building and Improvements				3,811,941
Gross Amount Carried at End of Period	$ 4,137,244			4,137,244
Accumulated Depreciation	$ 1,949,170			1,949,170
Date of Construction or Acquisition	1,979
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,137,244
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,949,170
Operating Properties [Member] | 4401-4445 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				615,038
Initial Cost of Buildings				4,510,272
Costs Capitalized Subsequent to Acquisition				590,263
Land and Improvements				615,038
Building and Improvements				5,100,535
Gross Amount Carried at End of Period	$ 5,715,573			5,715,573
Accumulated Depreciation	$ 2,849,707			2,849,707
Date of Construction or Acquisition	1,988
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,715,573
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,849,707
Operating Properties [Member] | 4447-4491 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				454,056
Initial Cost of Buildings				2,729,742
Costs Capitalized Subsequent to Acquisition				561,739
Land and Improvements				454,056
Building and Improvements				3,291,481
Gross Amount Carried at End of Period	$ 3,745,537			3,745,537
Accumulated Depreciation	$ 1,924,513			1,924,513
Date of Construction or Acquisition	1,987
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,745,537
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,924,513
Operating Properties [Member] | 4501-4549 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				486,166
Initial Cost of Buildings				3,565,211
Costs Capitalized Subsequent to Acquisition				588,371
Land and Improvements				486,166
Building and Improvements				4,153,582
Gross Amount Carried at End of Period	$ 4,639,748			4,639,748
Accumulated Depreciation	$ 2,416,513			2,416,513
Date of Construction or Acquisition	1,981
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,639,748
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,416,513
Operating Properties [Member] | 4551-4593 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				474,360
Initial Cost of Buildings				3,478,646
Costs Capitalized Subsequent to Acquisition				1,022,000
Land and Improvements				474,360
Building and Improvements				4,500,646
Gross Amount Carried at End of Period	$ 4,975,006			4,975,006
Accumulated Depreciation	$ 2,819,618			2,819,618
Date of Construction or Acquisition	1,982
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,975,006
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,819,618
Operating Properties [Member] | 4601-4643 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				652,455
Initial Cost of Buildings				4,784,675
Costs Capitalized Subsequent to Acquisition				1,194,888
Land and Improvements				652,455
Building and Improvements				5,979,563
Gross Amount Carried at End of Period	$ 6,632,018			6,632,018
Accumulated Depreciation	$ 3,375,244			3,375,244
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,632,018
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,375,244
Operating Properties [Member] | 4645-4683 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				404,616
Initial Cost of Buildings				2,967,187
Costs Capitalized Subsequent to Acquisition				640,579
Land and Improvements				404,616
Building and Improvements				3,607,766
Gross Amount Carried at End of Period	$ 4,012,382			4,012,382
Accumulated Depreciation	$ 2,066,465			2,066,465
Date of Construction or Acquisition	1,985
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,012,382
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,066,465
Operating Properties [Member] | 4717-4729 Eubank Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				449,447
Initial Cost of Buildings				3,294,697
Costs Capitalized Subsequent to Acquisition				2,231,233
Land and Improvements				452,263
Building and Improvements				5,523,114
Gross Amount Carried at End of Period	$ 5,975,377			5,975,377
Accumulated Depreciation	$ 3,101,325			3,101,325
Date of Construction or Acquisition	1,978
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,975,377
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,101,325
Operating Properties [Member] | 510 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				261,961
Initial Cost of Buildings				2,110,874
Costs Capitalized Subsequent to Acquisition				435,046
Land and Improvements				262,210
Building and Improvements				2,545,671
Gross Amount Carried at End of Period	$ 2,807,881			2,807,881
Accumulated Depreciation	$ 1,452,681			1,452,681
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,807,881
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,452,681
Operating Properties [Member] | 520 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				486,118
Initial Cost of Buildings				4,083,582
Costs Capitalized Subsequent to Acquisition				707,346
Land and Improvements				486,598
Building and Improvements				4,790,448
Gross Amount Carried at End of Period	$ 5,277,046			5,277,046
Accumulated Depreciation	$ 2,478,123			2,478,123
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,277,046
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,478,123
Operating Properties [Member] | 530 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				266,883
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,609,290
Land and Improvements				334,772
Building and Improvements				2,541,401
Gross Amount Carried at End of Period	$ 2,876,173			2,876,173
Accumulated Depreciation	$ 1,320,396			1,320,396
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,876,173
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,320,396
Operating Properties [Member] | 540 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				742,300
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,433,803
Land and Improvements				1,066,839
Building and Improvements				5,109,264
Gross Amount Carried at End of Period	$ 6,176,103			6,176,103
Accumulated Depreciation	$ 1,278,890			1,278,890
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,176,103
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,278,890
Operating Properties [Member] | 5600-5626 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				489,941
Initial Cost of Buildings				3,592,900
Costs Capitalized Subsequent to Acquisition				653,447
Land and Improvements				489,941
Building and Improvements				4,246,347
Gross Amount Carried at End of Period	$ 4,736,288			4,736,288
Accumulated Depreciation	$ 2,315,211			2,315,211
Date of Construction or Acquisition	1,989
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,736,288
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,315,211
Operating Properties [Member] | 5601-5659 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				705,660
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,775,225
Land and Improvements				720,100
Building and Improvements				4,760,785
Gross Amount Carried at End of Period	$ 5,480,885			5,480,885
Accumulated Depreciation	$ 2,656,819			2,656,819
Date of Construction or Acquisition	1,996
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,480,885
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,656,819
Operating Properties [Member] | 5650-5674 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				644,384
Initial Cost of Buildings				4,025,480
Costs Capitalized Subsequent to Acquisition				911,909
Land and Improvements				644,384
Building and Improvements				4,937,389
Gross Amount Carried at End of Period	$ 5,581,773			5,581,773
Accumulated Depreciation	$ 2,587,321			2,587,321
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,581,773
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,587,321
Operating Properties [Member] | 5700 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				408,729
Initial Cost of Buildings				2,697,348
Costs Capitalized Subsequent to Acquisition				1,248,597
Land and Improvements				408,729
Building and Improvements				3,945,945
Gross Amount Carried at End of Period	$ 4,354,674			4,354,674
Accumulated Depreciation	$ 2,349,031			2,349,031
Date of Construction or Acquisition	1,990
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,354,674
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,349,031
Operating Properties [Member] | 5701-5799 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				694,644
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,793,328
Land and Improvements				700,503
Building and Improvements				5,787,469
Gross Amount Carried at End of Period	$ 6,487,972			6,487,972
Accumulated Depreciation	$ 2,741,387			2,741,387
Date of Construction or Acquisition	1,998
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,487,972
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,741,387
Operating Properties [Member] | 5900 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				676,661
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,033,575
Land and Improvements				687,898
Building and Improvements				5,022,338
Gross Amount Carried at End of Period	$ 5,710,236			5,710,236
Accumulated Depreciation	$ 2,731,296			2,731,296
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,710,236
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,731,296
Operating Properties [Member] | 6000 Eastport Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				872,901
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,490,690
Land and Improvements				901,666
Building and Improvements				7,461,925
Gross Amount Carried at End of Period	$ 8,363,591			8,363,591
Accumulated Depreciation	$ 1,844,704			1,844,704
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,363,591
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,844,704
Operating Properties [Member] | 6530 Judge Adams Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rock Creek, NC
Encumbrances				0
Initial Cost of Land				305,821
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,984,310
Land and Improvements				335,061
Building and Improvements				4,955,070
Gross Amount Carried at End of Period	$ 5,290,131			5,290,131
Accumulated Depreciation	$ 2,445,869			2,445,869
Date of Construction or Acquisition	1,999
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,290,131
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,445,869
Operating Properties [Member] | 6532 Judge Adams Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rock Creek, NC
Encumbrances				0
Initial Cost of Land				354,903
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,029,460
Land and Improvements				399,988
Building and Improvements				3,984,375
Gross Amount Carried at End of Period	$ 4,384,363			4,384,363
Accumulated Depreciation	$ 2,132,455			2,132,455
Date of Construction or Acquisition	1,997
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,384,363
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,132,455
Operating Properties [Member] | 13098 George Weber Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rogers, MN
Encumbrances				0
Initial Cost of Land				895,811
Initial Cost of Buildings				6,004,189
Costs Capitalized Subsequent to Acquisition				342,789
Land and Improvements				895,811
Building and Improvements				6,346,978
Gross Amount Carried at End of Period	$ 7,242,789			7,242,789
Accumulated Depreciation	$ 1,131,645			1,131,645
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,242,789
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,131,645
Operating Properties [Member] | 13220 Wilfred Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rogers, MN
Encumbrances				0
Initial Cost of Land				508,532
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				11,262,730
Land and Improvements				1,396,324
Building and Improvements				10,374,938
Gross Amount Carried at End of Period	$ 11,771,262			11,771,262
Accumulated Depreciation	$ 1,167,513			1,167,513
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,771,262
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,167,513
Operating Properties [Member] | 13225 Brockton Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Rogers, MN
Encumbrances				0
Initial Cost of Land				1,048,093
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,465,007
Land and Improvements				1,066,159
Building and Improvements				10,446,941
Gross Amount Carried at End of Period	$ 11,513,100			11,513,100
Accumulated Depreciation	$ 1,095,596			1,095,596
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,513,100
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,095,596
Operating Properties [Member] | 1070 Windham Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Romeoville, IL
Encumbrances				0
Initial Cost of Land				8,672,143
Initial Cost of Buildings				24,144,864
Costs Capitalized Subsequent to Acquisition				1,240,599
Land and Improvements				8,672,143
Building and Improvements				25,385,463
Gross Amount Carried at End of Period	$ 34,057,606			34,057,606
Accumulated Depreciation	$ 3,444,236			3,444,236
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 34,057,606
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,444,236
Operating Properties [Member] | 1550 Central Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Roselle, IL
Encumbrances				0
Initial Cost of Land				2,884,492
Initial Cost of Buildings				10,439,793
Costs Capitalized Subsequent to Acquisition				1,445,451
Land and Improvements				2,884,492
Building and Improvements				11,885,244
Gross Amount Carried at End of Period	$ 14,769,736			14,769,736
Accumulated Depreciation	$ 1,757,721			1,757,721
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,769,736
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,757,721
Operating Properties [Member] | 1135 Aviation Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Fernando, CA
Encumbrances				0
Initial Cost of Land				3,035,034
Initial Cost of Buildings				2,844,962
Costs Capitalized Subsequent to Acquisition				460,883
Land and Improvements				3,035,034
Building and Improvements				3,305,845
Gross Amount Carried at End of Period	$ 6,340,879			6,340,879
Accumulated Depreciation	$ 520,419			520,419
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,340,879
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 520,419
Operating Properties [Member] | 8715 Bollman Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Savage, MD
Encumbrances				0
Initial Cost of Land				1,263,237
Initial Cost of Buildings				2,633,210
Costs Capitalized Subsequent to Acquisition				216,780
Land and Improvements				1,263,237
Building and Improvements				2,849,990
Gross Amount Carried at End of Period	$ 4,113,227			4,113,227
Accumulated Depreciation	$ 423,573			423,573
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,113,227
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 423,573
Operating Properties [Member] | 8501 East Raintree Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Scottsdale, AZ
Encumbrances				0
Initial Cost of Land				4,076,412
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				27,623,368
Land and Improvements				4,115,137
Building and Improvements				27,584,643
Gross Amount Carried at End of Period	$ 31,699,780			31,699,780
Accumulated Depreciation	$ 10,010,208			10,010,208
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 31,699,780
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 10,010,208
Operating Properties [Member] | 1150 Gateway Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Shakopee, MN
Encumbrances				0
Initial Cost of Land				1,126,865
Initial Cost of Buildings				5,684,178
Costs Capitalized Subsequent to Acquisition				208,099
Land and Improvements				1,126,865
Building and Improvements				5,892,277
Gross Amount Carried at End of Period	$ 7,019,142			7,019,142
Accumulated Depreciation	$ 797,282			797,282
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,019,142
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 797,282
Operating Properties [Member] | 5555 12th Avenue East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Shakopee, MN
Encumbrances				0
Initial Cost of Land				887,285
Initial Cost of Buildings				5,321,200
Costs Capitalized Subsequent to Acquisition				706,086
Land and Improvements				887,285
Building and Improvements				6,027,286
Gross Amount Carried at End of Period	$ 6,914,571			6,914,571
Accumulated Depreciation	$ 938,514			938,514
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,914,571
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 938,514
Operating Properties [Member] | 5651 Innovation Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Shakopee, MN
Encumbrances				0
Initial Cost of Land				1,551,579
Initial Cost of Buildings				9,541,234
Costs Capitalized Subsequent to Acquisition				1,836,241
Land and Improvements				1,552,083
Building and Improvements				11,376,971
Gross Amount Carried at End of Period	$ 12,929,054			12,929,054
Accumulated Depreciation	$ 620,019			620,019
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,929,054
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 620,019
Operating Properties [Member] | 12110 Champion Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sharonville, OH
Encumbrances				0
Initial Cost of Land				1,337,271
Initial Cost of Buildings				6,135,118
Costs Capitalized Subsequent to Acquisition				619,579
Land and Improvements				1,337,271
Building and Improvements				6,754,698
Gross Amount Carried at End of Period	$ 8,091,969			8,091,969
Accumulated Depreciation	$ 1,079,960			1,079,960
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,091,969
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,079,960
Operating Properties [Member] | 9300 Old Scotland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Shippensburg, PA
Encumbrances				0
Initial Cost of Land				10,232,633
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				84,620,569
Land and Improvements				12,933,027
Building and Improvements				81,920,175
Gross Amount Carried at End of Period	$ 94,853,202			94,853,202
Accumulated Depreciation	$ 8,405,238			8,405,238
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 94,853,202
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 8,405,238
Operating Properties [Member] | 3990 Heritage Oak Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Simi Valley, CA
Encumbrances				0
Initial Cost of Land				1,964,140
Initial Cost of Buildings				10,667,267
Costs Capitalized Subsequent to Acquisition				348,024
Land and Improvements				1,964,140
Building and Improvements				11,015,291
Gross Amount Carried at End of Period	$ 12,979,431			12,979,431
Accumulated Depreciation	$ 1,442,290			1,442,290
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,979,431
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,442,290
Operating Properties [Member] | 3654-3668 Swenson Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	St. Charles, IL
Encumbrances				0
Initial Cost of Land				643,639
Initial Cost of Buildings				1,645,058
Costs Capitalized Subsequent to Acquisition				241,111
Land and Improvements				643,639
Building and Improvements				1,886,169
Gross Amount Carried at End of Period	$ 2,529,808			2,529,808
Accumulated Depreciation	$ 272,149			272,149
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,529,808
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 272,149
Operating Properties [Member] | 3701 Illinois Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	St. Charles, IL
Encumbrances				0
Initial Cost of Land				672,500
Initial Cost of Buildings				1,288,924
Costs Capitalized Subsequent to Acquisition				136,087
Land and Improvements				672,500
Building and Improvements				1,425,011
Gross Amount Carried at End of Period	$ 2,097,511			2,097,511
Accumulated Depreciation	$ 239,510			239,510
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,097,511
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 239,510
Operating Properties [Member] | 3950-3980 Swenson Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	St. Charles, IL
Encumbrances				0
Initial Cost of Land				851,080
Initial Cost of Buildings				3,027,753
Costs Capitalized Subsequent to Acquisition				194,238
Land and Improvements				851,080
Building and Improvements				3,221,991
Gross Amount Carried at End of Period	$ 4,073,071			4,073,071
Accumulated Depreciation	$ 499,121			499,121
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,073,071
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 499,121
Operating Properties [Member] | 1501 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	St. Petersburg, FL
Encumbrances				0
Initial Cost of Land				283,474
Initial Cost of Buildings				2,230,868
Costs Capitalized Subsequent to Acquisition				175,893
Land and Improvements				283,474
Building and Improvements				2,406,760
Gross Amount Carried at End of Period	$ 2,690,234			2,690,234
Accumulated Depreciation	$ 343,528			343,528
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,690,234
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 343,528
Operating Properties [Member] | 1527 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	St. Petersburg, FL
Encumbrances				0
Initial Cost of Land				374,284
Initial Cost of Buildings				2,987,226
Costs Capitalized Subsequent to Acquisition				269,805
Land and Improvements				374,284
Building and Improvements				3,257,031
Gross Amount Carried at End of Period	$ 3,631,315			3,631,315
Accumulated Depreciation	$ 458,272			458,272
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,631,315
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 458,272
Operating Properties [Member] | 1551 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	St. Petersburg, FL
Encumbrances				0
Initial Cost of Land				699,797
Initial Cost of Buildings				5,214,438
Costs Capitalized Subsequent to Acquisition				1,049,801
Land and Improvements				699,797
Building and Improvements				6,264,239
Gross Amount Carried at End of Period	$ 6,964,036			6,964,036
Accumulated Depreciation	$ 958,613			958,613
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,964,036
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 958,613
Operating Properties [Member] | 6900 Harbor View Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Suffolk, VA
Encumbrances				0
Initial Cost of Land				904,052
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				8,905,485
Land and Improvements				807,006
Building and Improvements				9,002,531
Gross Amount Carried at End of Period	$ 9,809,537			9,809,537
Accumulated Depreciation	$ 2,821,271			2,821,271
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,809,537
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,821,271
Operating Properties [Member] | 6920 Harbour View Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Suffolk, VA
Encumbrances				0
Initial Cost of Land				603,391
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,811,694
Land and Improvements				2,628,635
Building and Improvements				4,786,450
Gross Amount Carried at End of Period	$ 7,415,085			7,415,085
Accumulated Depreciation	$ 826,103			826,103
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,415,085
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 826,103
Operating Properties [Member] | 6950 Harbour View Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Suffolk, VA
Encumbrances				0
Initial Cost of Land				929,844
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,399,035
Land and Improvements				794,848
Building and Improvements				6,534,031
Gross Amount Carried at End of Period	$ 7,328,879			7,328,879
Accumulated Depreciation	$ 2,021,547			2,021,547
Date of Construction or Acquisition	2,004
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,328,879
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,021,547
Operating Properties [Member] | 1516 Fryar Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sumner, WA
Encumbrances				0
Initial Cost of Land				1,675,402
Initial Cost of Buildings				5,079,543
Costs Capitalized Subsequent to Acquisition				889,814
Land and Improvements				1,675,402
Building and Improvements				5,969,357
Gross Amount Carried at End of Period	$ 7,644,759			7,644,759
Accumulated Depreciation	$ 1,021,745			1,021,745
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,644,759
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,021,745
Operating Properties [Member] | 3401-3409 Cragmont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				556,952
Initial Cost of Buildings				3,849,236
Costs Capitalized Subsequent to Acquisition				39,335
Land and Improvements				556,952
Building and Improvements				3,888,571
Gross Amount Carried at End of Period	$ 4,445,523			4,445,523
Accumulated Depreciation	$ 505,356			505,356
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,445,523
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 505,356
Operating Properties [Member] | 3502 Riga Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				201,600
Initial Cost of Buildings				1,263,131
Costs Capitalized Subsequent to Acquisition				239,882
Land and Improvements				201,600
Building and Improvements				1,503,013
Gross Amount Carried at End of Period	$ 1,704,613			1,704,613
Accumulated Depreciation	$ 181,319			181,319
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,704,613
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 181,319
Operating Properties [Member] | 3505 Cragmont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				936,336
Initial Cost of Buildings				7,155,520
Costs Capitalized Subsequent to Acquisition				1,886
Land and Improvements				936,336
Building and Improvements				7,157,406
Gross Amount Carried at End of Period	$ 8,093,742			8,093,742
Accumulated Depreciation	$ 1,016,212			1,016,212
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,093,742
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,016,212
Operating Properties [Member] | 3608 Queen Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				650,384
Initial Cost of Buildings				4,764,301
Costs Capitalized Subsequent to Acquisition				169,104
Land and Improvements				650,384
Building and Improvements				4,933,405
Gross Amount Carried at End of Period	$ 5,583,789			5,583,789
Accumulated Depreciation	$ 679,515			679,515
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,583,789
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 679,515
Operating Properties [Member] | 5250 Eagle Trail Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				952,860
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,636,749
Land and Improvements				952,860
Building and Improvements				3,636,749
Gross Amount Carried at End of Period	$ 4,589,609			4,589,609
Accumulated Depreciation	$ 1,710,467			1,710,467
Date of Construction or Acquisition	1,998
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,589,609
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,710,467
Operating Properties [Member] | 5501-5519 Pioneer Park Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				162,000
Initial Cost of Buildings				1,613,000
Costs Capitalized Subsequent to Acquisition				997,161
Land and Improvements				262,416
Building and Improvements				2,509,745
Gross Amount Carried at End of Period	$ 2,772,161			2,772,161
Accumulated Depreciation	$ 1,486,601			1,486,601
Date of Construction or Acquisition	1,981
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,772,161
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,486,601
Operating Properties [Member] | 5690-5694 Crenshaw Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				181,923
Initial Cost of Buildings				1,812,496
Costs Capitalized Subsequent to Acquisition				1,023,603
Land and Improvements				181,923
Building and Improvements				2,836,099
Gross Amount Carried at End of Period	$ 3,018,022			3,018,022
Accumulated Depreciation	$ 1,441,409			1,441,409
Date of Construction or Acquisition	1,979
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,018,022
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,441,409
Operating Properties [Member] | 8110 Anderson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				912,663
Initial Cost of Buildings				5,425,143
Costs Capitalized Subsequent to Acquisition				357,958
Land and Improvements				912,663
Building and Improvements				5,783,101
Gross Amount Carried at End of Period	$ 6,695,764			6,695,764
Accumulated Depreciation	$ 884,161			884,161
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,695,764
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 884,161
Operating Properties [Member] | 8130 Anderson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				655,668
Initial Cost of Buildings				4,132,076
Costs Capitalized Subsequent to Acquisition				135,482
Land and Improvements				655,668
Building and Improvements				4,267,558
Gross Amount Carried at End of Period	$ 4,923,226			4,923,226
Accumulated Depreciation	$ 640,520			640,520
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,923,226
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 640,520
Operating Properties [Member] | 9020 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				1,718,496
Initial Cost of Buildings				11,697,381
Costs Capitalized Subsequent to Acquisition				913,458
Land and Improvements				1,718,496
Building and Improvements				12,610,839
Gross Amount Carried at End of Period	$ 14,329,335			14,329,335
Accumulated Depreciation	$ 1,699,170			1,699,170
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,329,335
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,699,170
Operating Properties [Member] | 9110 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				1,203,200
Initial Cost of Buildings				7,979,540
Costs Capitalized Subsequent to Acquisition				764,935
Land and Improvements				1,203,200
Building and Improvements				8,744,475
Gross Amount Carried at End of Period	$ 9,947,675			9,947,675
Accumulated Depreciation	$ 1,144,622			1,144,622
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,947,675
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,144,622
Operating Properties [Member] | 9203 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				754,832
Initial Cost of Buildings				4,966,864
Costs Capitalized Subsequent to Acquisition				(33,052)
Land and Improvements				754,832
Building and Improvements				4,933,812
Gross Amount Carried at End of Period	$ 5,688,644			5,688,644
Accumulated Depreciation	$ 705,090			705,090
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,688,644
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 705,090
Operating Properties [Member] | 9319 Peach Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				612,536
Initial Cost of Buildings				4,168,473
Costs Capitalized Subsequent to Acquisition				10,035
Land and Improvements				612,536
Building and Improvements				4,178,508
Gross Amount Carried at End of Period	$ 4,791,044			4,791,044
Accumulated Depreciation	$ 553,112			553,112
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,791,044
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 553,112
Operating Properties [Member] | 9704 Solar Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				374,548
Initial Cost of Buildings				1,354,800
Costs Capitalized Subsequent to Acquisition				763,058
Land and Improvements				374,548
Building and Improvements				2,117,858
Gross Amount Carried at End of Period	$ 2,492,406			2,492,406
Accumulated Depreciation	$ 260,248			260,248
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,492,406
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 260,248
Operating Properties [Member] | 9945 Currie Davis Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				1,134,286
Initial Cost of Buildings				9,241,807
Costs Capitalized Subsequent to Acquisition				381,604
Land and Improvements				1,134,286
Building and Improvements				9,623,410
Gross Amount Carried at End of Period	$ 10,757,696			10,757,696
Accumulated Depreciation	$ 1,384,379			1,384,379
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,757,696
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,384,379
Operating Properties [Member] | 1850 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				3,975,600
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				23,099,819
Land and Improvements				3,975,600
Building and Improvements				23,099,819
Gross Amount Carried at End of Period	$ 27,075,419			27,075,419
Accumulated Depreciation	$ 1,824,610			1,824,610
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 27,075,419
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,824,610
Operating Properties [Member] | 1858 E Encanto Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				877,611
Initial Cost of Buildings				4,485,427
Costs Capitalized Subsequent to Acquisition				412,814
Land and Improvements				877,611
Building and Improvements				4,898,241
Gross Amount Carried at End of Period	$ 5,775,852			5,775,852
Accumulated Depreciation	$ 736,485			736,485
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,775,852
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 736,485
Operating Properties [Member] | 475 W Vaughn St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				1,112,245
Initial Cost of Buildings				2,260,348
Costs Capitalized Subsequent to Acquisition				292,646
Land and Improvements				1,112,245
Building and Improvements				2,552,994
Gross Amount Carried at End of Period	$ 3,665,239			3,665,239
Accumulated Depreciation	$ 430,748			430,748
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,665,239
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 430,748
Operating Properties [Member] | 921 South Park Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				1,192,820
Initial Cost of Buildings				1,580,155
Costs Capitalized Subsequent to Acquisition				481,163
Land and Improvements				1,192,820
Building and Improvements				2,061,319
Gross Amount Carried at End of Period	$ 3,254,139			3,254,139
Accumulated Depreciation	$ 472,215			472,215
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,254,139
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 472,215
Operating Properties [Member] | 8313 West Pierce Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tolleson, AZ
Encumbrances				0
Initial Cost of Land				2,295,090
Initial Cost of Buildings				9,079,811
Costs Capitalized Subsequent to Acquisition				4,106,812
Land and Improvements				2,295,090
Building and Improvements				13,186,623
Gross Amount Carried at End of Period	$ 15,481,713			15,481,713
Accumulated Depreciation	$ 4,180,357			4,180,357
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,481,713
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 4,180,357
Operating Properties [Member] | 8591 West Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tolleson, AZ
Encumbrances				0
Initial Cost of Land				1,574,912
Initial Cost of Buildings				7,308,021
Costs Capitalized Subsequent to Acquisition				416,866
Land and Improvements				1,574,912
Building and Improvements				7,724,887
Gross Amount Carried at End of Period	$ 9,299,799			9,299,799
Accumulated Depreciation	$ 1,174,021			1,174,021
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 9,299,799
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,174,021
Operating Properties [Member] | 8601 West Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tolleson, AZ
Encumbrances				0
Initial Cost of Land				1,524,603
Initial Cost of Buildings				6,352,070
Costs Capitalized Subsequent to Acquisition				725,161
Land and Improvements				1,524,603
Building and Improvements				7,077,231
Gross Amount Carried at End of Period	$ 8,601,834			8,601,834
Accumulated Depreciation	$ 1,343,235			1,343,235
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,601,834
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,343,235
Operating Properties [Member] | 5111 S Royal Atlanta Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tucker, GA
Encumbrances				0
Initial Cost of Land				435,776
Initial Cost of Buildings				1,875,685
Costs Capitalized Subsequent to Acquisition				499,788
Land and Improvements				435,776
Building and Improvements				2,375,474
Gross Amount Carried at End of Period	$ 2,811,250			2,811,250
Accumulated Depreciation	$ 429,327			429,327
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,811,250
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 429,327
Operating Properties [Member] | 5151 S Royal Atlanta Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tucker, GA
Encumbrances				0
Initial Cost of Land				345,061
Initial Cost of Buildings				1,428,840
Costs Capitalized Subsequent to Acquisition				328,461
Land and Improvements				345,061
Building and Improvements				1,757,301
Gross Amount Carried at End of Period	$ 2,102,362			2,102,362
Accumulated Depreciation	$ 330,717			330,717
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,102,362
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 330,717
Operating Properties [Member] | 1100 17th Street NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Washington, DC
Encumbrances				0
Initial Cost of Land				16,558,660
Initial Cost of Buildings				32,223,978
Costs Capitalized Subsequent to Acquisition				4,819,314
Land and Improvements				16,558,660
Building and Improvements				37,043,292
Gross Amount Carried at End of Period	$ 53,601,952			53,601,952
Accumulated Depreciation	$ 7,352,708			7,352,708
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 53,601,952
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 7,352,708
Operating Properties [Member] | 2100 M Street NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Washington, DC
Encumbrances				0
Initial Cost of Land				70,000,000
Initial Cost of Buildings				55,123,783
Costs Capitalized Subsequent to Acquisition				1,912,347
Land and Improvements				70,000,000
Building and Improvements				57,036,130
Gross Amount Carried at End of Period	$ 127,036,130			127,036,130
Accumulated Depreciation	$ 8,404,405			8,404,405
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 127,036,130
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 8,404,405
Operating Properties [Member] | 1400 Powis Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Chicago, IL
Encumbrances				0
Initial Cost of Land				578,314
Initial Cost of Buildings				2,448,562
Costs Capitalized Subsequent to Acquisition				73,579
Land and Improvements				578,314
Building and Improvements				2,522,141
Gross Amount Carried at End of Period	$ 3,100,455			3,100,455
Accumulated Depreciation	$ 337,290			337,290
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,100,455
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 337,290
Operating Properties [Member] | 1 Kings Hill Aveune [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				4,288,389
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,930,852
Land and Improvements				3,381,307
Building and Improvements				8,837,934
Gross Amount Carried at End of Period	$ 12,219,241			12,219,241
Accumulated Depreciation	$ 2,698,820			2,698,820
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,219,241
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,698,820
Operating Properties [Member] | 42 Kings Hill Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				5,397,739
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,206,094
Land and Improvements				3,670,842
Building and Improvements				11,932,991
Gross Amount Carried at End of Period	$ 15,603,833			15,603,833
Accumulated Depreciation	$ 3,132,365			3,132,365
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,603,833
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,132,365
Operating Properties [Member] | Liberty Square, Block 1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				159,232
Initial Cost of Buildings				1,622,551
Costs Capitalized Subsequent to Acquisition				658,791
Land and Improvements				271,905
Building and Improvements				2,168,670
Gross Amount Carried at End of Period	$ 2,440,575			2,440,575
Accumulated Depreciation	$ 697,578			697,578
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,440,575
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 697,578
Operating Properties [Member] | Liberty Square, Block 2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				199,150
Initial Cost of Buildings				1,614,217
Costs Capitalized Subsequent to Acquisition				689,302
Land and Improvements				340,070
Building and Improvements				2,162,599
Gross Amount Carried at End of Period	$ 2,502,669			2,502,669
Accumulated Depreciation	$ 674,983			674,983
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,502,669
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 674,983
Operating Properties [Member] | Liberty Square, Block 3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				129,830
Initial Cost of Buildings				1,141,141
Costs Capitalized Subsequent to Acquisition				479,536
Land and Improvements				221,698
Building and Improvements				1,528,809
Gross Amount Carried at End of Period	$ 1,750,507			1,750,507
Accumulated Depreciation	$ 471,382			471,382
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,750,507
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 471,382
Operating Properties [Member] | Liberty Square, Block 5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Malling, UK
Encumbrances				0
Initial Cost of Land				71,377
Initial Cost of Buildings				735,993
Costs Capitalized Subsequent to Acquisition				298,534
Land and Improvements				121,883
Building and Improvements				984,021
Gross Amount Carried at End of Period	$ 1,105,904			1,105,904
Accumulated Depreciation	$ 303,533			303,533
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,105,904
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 303,533
Operating Properties [Member] | 1400 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Palm Beach, FL
Encumbrances				0
Initial Cost of Land				2,454,972
Initial Cost of Buildings				5,312,829
Costs Capitalized Subsequent to Acquisition				376,958
Land and Improvements				2,454,972
Building and Improvements				5,689,787
Gross Amount Carried at End of Period	$ 8,144,759			8,144,759
Accumulated Depreciation	$ 931,000			931,000
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,144,759
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 931,000
Operating Properties [Member] | 300 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Palm Beach, FL
Encumbrances				0
Initial Cost of Land				1,177,064
Initial Cost of Buildings				2,102,451
Costs Capitalized Subsequent to Acquisition				160,551
Land and Improvements				1,177,064
Building and Improvements				2,263,002
Gross Amount Carried at End of Period	$ 3,440,066			3,440,066
Accumulated Depreciation	$ 358,777			358,777
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,440,066
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 358,777
Operating Properties [Member] | 400 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Palm Beach, FL
Encumbrances				0
Initial Cost of Land				1,029,595
Initial Cost of Buildings				1,728,187
Costs Capitalized Subsequent to Acquisition				180,766
Land and Improvements				1,029,595
Building and Improvements				1,908,953
Gross Amount Carried at End of Period	$ 2,938,548			2,938,548
Accumulated Depreciation	$ 312,382			312,382
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,938,548
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 312,382
Operating Properties [Member] | 2935 West Corporate Lakes Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Weston, FL
Encumbrances				0
Initial Cost of Land				4,682,521
Initial Cost of Buildings				25,905,126
Costs Capitalized Subsequent to Acquisition				1,435,528
Land and Improvements				4,682,521
Building and Improvements				27,340,654
Gross Amount Carried at End of Period	$ 32,023,175			32,023,175
Accumulated Depreciation	$ 3,358,697			3,358,697
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 32,023,175
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 3,358,697
Operating Properties [Member] | 2945 West Corporate Lakes Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Weston, FL
Encumbrances				0
Initial Cost of Land				2,345,242
Initial Cost of Buildings				13,973,766
Costs Capitalized Subsequent to Acquisition				293,777
Land and Improvements				2,345,242
Building and Improvements				14,267,543
Gross Amount Carried at End of Period	$ 16,612,785			16,612,785
Accumulated Depreciation	$ 1,709,525			1,709,525
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 16,612,785
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,709,525
Operating Properties [Member] | 43-47 Hintz Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Wheeling, IL
Encumbrances				0
Initial Cost of Land				2,051,093
Initial Cost of Buildings				18,283,480
Costs Capitalized Subsequent to Acquisition				539,342
Land and Improvements				2,051,093
Building and Improvements				18,822,823
Gross Amount Carried at End of Period	$ 20,873,916			20,873,916
Accumulated Depreciation	$ 2,475,574			2,475,574
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,873,916
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	2,475,574
Operating Properties [Member] | Subtotal Operating Real Estate [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				47,946,455
Initial Cost of Land				1,099,713,438
Initial Cost of Buildings				2,336,140,008
Costs Capitalized Subsequent to Acquisition				2,161,408,921
Land and Improvements				1,153,680,251
Building and Improvements				4,443,582,109
Gross Amount Carried at End of Period	5,597,262,360			5,597,262,360
Accumulated Depreciation	940,612,342			940,612,342
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	5,597,262,360
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 940,612,342
Operating Properties [Member] | 11020 Holly Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dayton, MN
Encumbrances				0
Initial Cost of Land				2,536,731
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				12,722,576
Land and Improvements				2,536,731
Building and Improvements				12,722,576
Gross Amount Carried at End of Period	$ 15,259,307			15,259,307
Accumulated Depreciation	$ 475,069			475,069
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,259,307
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 475,069
Operating Properties [Member] | 333 Howard Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Des Plaines, IL
Encumbrances				0
Initial Cost of Land				7,928,724
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				14,264,248
Land and Improvements				7,928,724
Building and Improvements				14,264,248
Gross Amount Carried at End of Period	$ 22,192,972			22,192,972
Accumulated Depreciation	$ 832,239			832,239
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 22,192,972
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 832,239
Operating Properties [Member] | 1951 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				1,115,595
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,618,500
Land and Improvements				1,324,734
Building and Improvements				3,409,361
Gross Amount Carried at End of Period	$ 4,734,095			4,734,095
Accumulated Depreciation	$ 68,813			68,813
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,734,095
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	68,813
Operating Properties [Member] | 1953 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				0
Initial Cost of Land				2,402,820
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,583,503
Land and Improvements				2,853,273
Building and Improvements				6,133,050
Gross Amount Carried at End of Period	8,986,323			8,986,323
Accumulated Depreciation	$ 103,698			103,698
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,986,323
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 103,698
Operating Properties [Member] | 2988 Green Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				2,271,948
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,598,421
Land and Improvements				2,095,033
Building and Improvements				6,775,336
Gross Amount Carried at End of Period	$ 8,870,369			8,870,369
Accumulated Depreciation	$ 56,411			56,411
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,870,369
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 56,411
Operating Properties [Member] | 125 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				464,237
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,840,213
Land and Improvements				1,311,956
Building and Improvements				4,992,494
Gross Amount Carried at End of Period	$ 6,304,450			6,304,450
Accumulated Depreciation	$ 1,143,185			1,143,185
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,304,450
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,143,185
Operating Properties [Member] | 2727 London Groveport Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Groveport, OH
Encumbrances				0
Initial Cost of Land				1,875,607
Initial Cost of Buildings				11,937,935
Costs Capitalized Subsequent to Acquisition				1,594,848
Land and Improvements				1,875,607
Building and Improvements				13,532,783
Gross Amount Carried at End of Period	$ 15,408,390			15,408,390
Accumulated Depreciation	$ 2,154,022			2,154,022
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,408,390
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 2,154,022
Operating Properties [Member] | 120 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				1,243,100
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,603,603
Land and Improvements				1,255,751
Building and Improvements				6,590,952
Gross Amount Carried at End of Period	$ 7,846,703			7,846,703
Accumulated Depreciation	$ 516,447			516,447
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,846,703
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 516,447
Operating Properties [Member] | 130 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				1,171,160
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,045,497
Land and Improvements				1,183,811
Building and Improvements				6,032,846
Gross Amount Carried at End of Period	$ 7,216,657			7,216,657
Accumulated Depreciation	$ 326,307			326,307
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,216,657
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 326,307
Operating Properties [Member] | 4485 Premier Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	High Point, NC
Encumbrances				0
Initial Cost of Land				1,827,595
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				6,507,936
Land and Improvements				1,827,595
Building and Improvements				6,507,936
Gross Amount Carried at End of Period	$ 8,335,531			8,335,531
Accumulated Depreciation	$ 174,125			174,125
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,335,531
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 174,125
Operating Properties [Member] | 5430 FAA Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irving, TX
Encumbrances				0
Initial Cost of Land				2,245,346
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				11,190,939
Land and Improvements				3,198,031
Building and Improvements				10,238,254
Gross Amount Carried at End of Period	$ 13,436,285			13,436,285
Accumulated Depreciation	$ 101,529			101,529
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,436,285
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 101,529
Operating Properties [Member] | 951 Valleyview Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irving, TX
Encumbrances				0
Initial Cost of Land				3,899,824
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				14,284,349
Land and Improvements				5,554,903
Building and Improvements				12,629,270
Gross Amount Carried at End of Period	$ 18,184,173			18,184,173
Accumulated Depreciation	$ 225,454			225,454
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 18,184,173
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 225,454
Operating Properties [Member] | 1200 Claybrick Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Landover,MD
Encumbrances				0
Initial Cost of Land				6,876,500
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,392,716
Land and Improvements				4,997,416
Building and Improvements				7,271,800
Gross Amount Carried at End of Period	$ 12,269,216			12,269,216
Accumulated Depreciation	$ 122,940			122,940
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,269,216
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 122,940
Operating Properties [Member] | 1801 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				3,794,963
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				24,116,063
Land and Improvements				5,421,262
Building and Improvements				22,489,764
Gross Amount Carried at End of Period	$ 27,911,026			27,911,026
Accumulated Depreciation	$ 48,880			48,880
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 27,911,026
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 48,880
Operating Properties [Member] | 11440 NW 122 Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Miami, FL
Encumbrances				0
Initial Cost of Land				5,636,564
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,787,507
Land and Improvements				5,944,709
Building and Improvements				10,479,362
Gross Amount Carried at End of Period	$ 16,424,071			16,424,071
Accumulated Depreciation	$ 135,226			135,226
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 16,424,071
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 135,226
Operating Properties [Member] | 11250 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Medley, FL
Encumbrances				0
Initial Cost of Land				4,798,886
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,229,788
Land and Improvements				4,798,886
Building and Improvements				9,229,788
Gross Amount Carried at End of Period	$ 14,028,674			14,028,674
Accumulated Depreciation	$ 442,152			442,152
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,028,674
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 442,152
Operating Properties [Member] | 1500 S 71st Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Phoenix, AZ
Encumbrances				0
Initial Cost of Land				4,234,407
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,162,853
Land and Improvements				3,333,729
Building and Improvements				11,063,531
Gross Amount Carried at End of Period	$ 14,397,260			14,397,260
Accumulated Depreciation	$ 155,768			155,768
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,397,260
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 155,768
Operating Properties [Member] | 1200 Intrepid Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				404,883
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				29,737,547
Land and Improvements				455,507
Building and Improvements				29,686,923
Gross Amount Carried at End of Period	$ 30,142,430			30,142,430
Accumulated Depreciation	$ 548,890			548,890
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 30,142,430
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 548,890
Operating Properties [Member] | 7205 W Buckeye Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Phoenix, AZ
Encumbrances				0
Initial Cost of Land				2,514,425
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,725,015
Land and Improvements				2,514,425
Building and Improvements				10,725,015
Gross Amount Carried at End of Period	$ 13,239,440			13,239,440
Accumulated Depreciation	$ 155,365			155,365
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,239,440
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 155,365
Operating Properties [Member] | 4701 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				419,107
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				13,301,142
Land and Improvements				435,763
Building and Improvements				13,284,486
Gross Amount Carried at End of Period	$ 13,720,249			13,720,249
Accumulated Depreciation	$ 688,698			688,698
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,720,249
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 688,698
Operating Properties [Member] | 5800 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Richmond, VA
Encumbrances				0
Initial Cost of Land				604,146
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,591,578
Land and Improvements				604,146
Building and Improvements				7,591,578
Gross Amount Carried at End of Period	$ 8,195,724			8,195,724
Accumulated Depreciation	$ 419,106			419,106
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,195,724
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 419,106
Operating Properties [Member] | 5800 Technology Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sandston, VA
Encumbrances				0
Initial Cost of Land				1,741,867
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				12,042,698
Land and Improvements				1,744,160
Building and Improvements				12,040,405
Gross Amount Carried at End of Period	$ 13,784,565			13,784,565
Accumulated Depreciation	$ 426,034			426,034
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,784,565
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 426,034
Operating Properties [Member] | 1910 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				4,693,504
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				24,629,008
Land and Improvements				4,693,504
Building and Improvements				24,629,008
Gross Amount Carried at End of Period	$ 29,322,512			29,322,512
Accumulated Depreciation	$ 1,755,471			1,755,471
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 29,322,512
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 1,755,471
Operating Properties [Member] | 1930 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				4,069,890
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				24,158,460
Land and Improvements				4,069,890
Building and Improvements				24,158,460
Gross Amount Carried at End of Period	$ 28,228,350			28,228,350
Accumulated Depreciation	$ 702,240			702,240
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 28,228,350
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 702,240
Operating Properties [Member] | 2040 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				3,225,000
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				12,531,731
Land and Improvements				3,225,000
Building and Improvements				12,531,731
Gross Amount Carried at End of Period	$ 15,756,731			15,756,731
Accumulated Depreciation	$ 547,526			547,526
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 15,756,731
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 547,526
Operating Properties [Member] | 6017 Southern Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Palm Beach, FL
Encumbrances				0
Initial Cost of Land				4,513,860
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,167,515
Land and Improvements				4,513,860
Building and Improvements				9,167,515
Gross Amount Carried at End of Period	$ 13,681,375			13,681,375
Accumulated Depreciation	$ 38,247			38,247
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,681,375
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 38,247
Operating Properties [Member] | 6035 Southern Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	West Palm Beach, FL
Encumbrances				0
Initial Cost of Land				2,499,894
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,401,996
Land and Improvements				2,499,984
Building and Improvements				5,401,906
Gross Amount Carried at End of Period	$ 7,901,890			7,901,890
Accumulated Depreciation	$ 24,187			24,187
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,901,890
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 24,187
Operating Properties [Member] | Worcester 1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Worcester, UK
Encumbrances				0
Initial Cost of Land				843,256
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,234,133
Land and Improvements				1,175,040
Building and Improvements				3,902,349
Gross Amount Carried at End of Period	$ 5,077,389			5,077,389
Accumulated Depreciation	$ 12,897			12,897
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,077,389
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 12,897
Operating Properties [Member] | Maximum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)
Operating Properties [Member] | Maximum [Member] | 627 Distribution Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1467 Perryman Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1501 Perryman Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 869 S Route 53 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 901 S Route 53 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8620 Congdon Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 200 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 250 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 400 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 650 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 651 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 700 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 705 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7165 Ambassador Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7248 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7339 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7437 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8014 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8150 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8250 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8400 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6330 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6350 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6370 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6390 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6520 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6540 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6560 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6580 Snowdrift Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7620 Cetronia Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11222 Melrose Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3095 Presidential Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3097 Presidential Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7030 Buford Highway NE [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Barton 150 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1055-1071 Kingsland Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4606 Richlynn Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11800 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11850 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11900 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16420 West Hardy Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12104 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12200 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12240 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1071 Thorndale Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1260-1274 Ellis Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 371-377 Meyer Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 850-880 Devon Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10 Emery Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2785 Commerce Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1455 Remington Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 150 E Crossroads Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 553 S Joliet Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 400 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8201 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8451 Willard Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 860 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3525 Gravel Springs Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1485 W Commerce Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 40 Logistics Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 135-195 East Elk Trail [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 515 Kehoe Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1413 Bradley Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3200 Belmeade Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16325 S Avalon Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1475 Nitterhouse Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 95 Kriner Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9000 109th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11701 Goodrich Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12810 Virkler Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2700 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2701 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2730 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2801 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3000 Crosspoint Center Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3005 Crosspoint Center Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4045 Perimeter West Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4047 Perimeter West Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4525 Statesville Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4835 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4925 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5032 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5033 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5039 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8910 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8916 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8924 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2601 Indian River Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1540 S 54th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4650 Lake Forest Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4750 Lake Forest Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9645 Gerwig Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2550 John Glenn Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3800 Twin Creeks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 330 South Royal Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 455 Airline Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2130 Baldwin Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 329-333 Herrod Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1250 Hall Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1680 Executive Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1700 Executive Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2670 Breckinridge Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 170 Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 190 Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 265 Parkway East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 285 Parkway East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1000 Parliament Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4226 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4227 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4234 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4300 Emperor Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1957 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3169 Dodd Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3711 Kennebec Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 917 Lone Oak Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10301-10305 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10321 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10333 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10349-10357 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10365-10375 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10393-10394 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7075 Flying Cloud Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7078 Shady Oak Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1 Truman Drive South [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2250 Arthur Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6600 Business Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6675 Business Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7351 Coca Cola Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 21705-21707 Mississippi Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 27143 Elwood International Port Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1800 Donaldson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6880 Fairfield Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7000-7018 Fairfield Business [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10721 Jasmine Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2000 Southpointe Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1400 NW 65th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6500 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6501 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6600 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9601 Cosner Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5410 - 5430 Northwest 33rd Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12601 Industry Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12641 Industry Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12681-12691 Pala Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 850 S Jupiter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2510 W Main Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4251 North Highway 121 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1150 Pleasant Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 25 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 45 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2011 Southtech Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2121 Southtech Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 800 Commerce Parkway West Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 110 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 140 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11835 Newgate Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11841 Newgate Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1560 Hunter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1575 Hunter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7361 Coca Cola Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7460 New Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7462 New Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 500 McCarthy Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 600 Industrial Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7195 Grayson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7253 Grayson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12537 Cerise Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1010 Petersburg Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 785 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 805 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 825 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 845 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4198 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4183 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4189 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4193 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4328, 4336 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4344 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4380 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4388 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4475 Premier Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4500 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4501 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4523 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4524 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9600 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Unit 5 Logix Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1000 South Loop West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10241 W Little York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10245 W Little York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10301 Round Up Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10305 Round Up Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1050 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10607 Haddington Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10735 West Little York Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10739 West Little York Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11201 Greens Crossing Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11220 Ella Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1283 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1287 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1291 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1416 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1420 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 14200 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1424 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1428 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 14300 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 14400 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 15102 Sommermeyer St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 15150 Sommermeyer St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16330 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16420 West Hardy Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16445 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1646 Rankin Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1655 Townhurst Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16580 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16602 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16605 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1665 Townhurst Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16680 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16685 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1755 Trans Central Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4301 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4401 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4501 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5200 N. Sam Houston Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5250 N. Sam Houston Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5500 N. Sam Houston Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8017 Pinemont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8272 El Rio Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8282 El Rio Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8301 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8303 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 850 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 860 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8801-19 & 8821-49 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8802-8824 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8825-8839 N Sam Houston Pkwy [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8850-8872 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 16200 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Cabot III UK1B01 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1011 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1035 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1549 W Glenlake Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 901 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 925 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8241 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8242 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8246 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1305 Chastain Road NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1325 Chastain Road NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3600 Cobb International Bld NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Unit 1 Bear Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 650 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 680 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1770 Interstate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5801 Columbia Park Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11425 State Highway 225 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11503 State Highway 225 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1701 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1842 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1902 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 640 S State Road 39 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7528 Walker Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8301 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8500 Willard Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7533 Industrial Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 100 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1001 Cedar Hollow Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12,14,16 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 14 Lee Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 18 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 311 Technology Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 425 Old Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 50 Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 60 Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 600 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 700 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1169 Canton Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 65 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 75 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 126-132 Liberty Industrial Pkw [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 95-115 Liberty Industrial Pkwy [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11150 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11401 NW 134th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11450 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 456 International Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 21 S Middlesex Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4 S Middlesex Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 250 Moonachie Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 230 Moonachie Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 22750 Cactus Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 150 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 323 Park Knoll Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 324 Park Knoll Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 619 Distribution Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1879 Lamont Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 350 Winmeyer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4000 E Airport Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1000 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10003 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10511 & 10611 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 10771 Palm Bay Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1090 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1600-1650 Central Florida Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1902 Cypress Lake Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2000 Park Oaks Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2202 Taft-Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2212 Taft Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2256 Taft-Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2351 Investors Row [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2400 South Lake Orange Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2412 Sand Lake Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2416 Lake Orange Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6200 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6989 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6918 Presidents Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6923 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7022 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7100 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7101 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7315 Kingspointe Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 851 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 950 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 29 Liberty Square [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9550 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3535 Gravel Springs Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9700 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1 Crescent Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 201 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 351 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4000 S 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4300 South 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4751 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4775 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8th & Walnut Streets [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2626 South 7th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 563 South 63rd Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1000 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1901 10th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1909 10th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3605 East Plano Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3701 East Plano Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 800 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 900 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9801 80th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 14630-14650 28th Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2920 Northwest Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5905 Trenton Lane North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6055 Nathan Lane North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1400 SW 6th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1405 SW 6th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1500 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1501 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1601 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1651 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2201-2215 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2250-2270 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2280-2300 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2301-2329 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3000 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3001-3037 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3012-3050 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 595 SW 13th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 601 SW 13th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 605 SW 16th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2459 Almond Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1221 N Alder Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1920 West Baseline Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 301 Hill Carter Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4101-4127 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4201-4261 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4263-4299 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4263F-N. Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4301-4335 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4337-4379 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4401-4445 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4447-4491 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4501-4549 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4551-4593 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4601-4643 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4645-4683 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4717-4729 Eubank Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 510 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 520 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 530 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 540 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5600-5626 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5601-5659 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5650-5674 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5700 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5701-5799 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5900 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6000 Eastport Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6530 Judge Adams Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6532 Judge Adams Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 13098 George Weber Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 13220 Wilfred Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 13225 Brockton Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1070 Windham Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1550 Central Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1135 Aviation Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8715 Bollman Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8501 East Raintree Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1150 Gateway Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5555 12th Avenue East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5651 Innovation Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 12110 Champion Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9300 Old Scotland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3990 Heritage Oak Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3654-3668 Swenson Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3701 Illinois Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3950-3980 Swenson Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1501 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1527 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1551 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6900 Harbor View Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6920 Harbour View Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6950 Harbour View Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1516 Fryar Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3401-3409 Cragmont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3502 Riga Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3505 Cragmont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 3608 Queen Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5250 Eagle Trail Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5501-5519 Pioneer Park Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5690-5694 Crenshaw Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8110 Anderson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8130 Anderson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9020 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9110 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9203 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9319 Peach Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9704 Solar Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 9945 Currie Davis Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1850 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1858 E Encanto Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 475 W Vaughn St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 921 South Park Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8313 West Pierce Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8591 West Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 8601 West Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5111 S Royal Atlanta Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5151 S Royal Atlanta Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1100 17th Street NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2100 M Street NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1400 Powis Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1 Kings Hill Aveune [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 42 Kings Hill Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Liberty Square, Block 1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Liberty Square, Block 2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Liberty Square, Block 3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Liberty Square, Block 5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1400 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 300 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 400 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2935 West Corporate Lakes Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2945 West Corporate Lakes Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 43-47 Hintz Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11020 Holly Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1951 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1953 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2988 Green Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 125 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2727 London Groveport Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 120 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 130 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4485 Premier Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5430 FAA Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 951 Valleyview Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1200 Claybrick Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1801 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11440 NW 122 Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 11250 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1500 S 71st Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 7205 W Buckeye Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 4701 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5800 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 5800 Technology Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1910 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 1930 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 2040 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6017 Southern Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | 6035 Southern Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Maximum [Member] | Worcester 1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	40 years
Operating Properties [Member] | Minimum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)
Operating Properties [Member] | Minimum [Member] | 627 Distribution Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1467 Perryman Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1501 Perryman Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 869 S Route 53 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 901 S Route 53 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8620 Congdon Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 200 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 250 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 400 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 650 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 651 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 700 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 705 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7165 Ambassador Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7248 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7339 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7437 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8014 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8150 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8250 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8400 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6330 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6350 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6370 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6390 Hedgewood Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6520 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6540 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6560 Stonegate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6580 Snowdrift Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7620 Cetronia Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11222 Melrose Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3095 Presidential Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3097 Presidential Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7030 Buford Highway NE [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Barton 150 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1055-1071 Kingsland Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4606 Richlynn Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11800 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11850 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11900 Baltimore Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16420 West Hardy Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12104 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12200 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12240 Indian Creek Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1071 Thorndale Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1260-1274 Ellis Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 371-377 Meyer Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 850-880 Devon Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10 Emery Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2785 Commerce Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1455 Remington Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 150 E Crossroads Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 553 S Joliet Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 400 Boulder Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8201 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8451 Willard Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 860 Nestle Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3525 Gravel Springs Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1485 W Commerce Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 40 Logistics Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 135-195 East Elk Trail [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 515 Kehoe Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1413 Bradley Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3200 Belmeade Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16325 S Avalon Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1475 Nitterhouse Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 95 Kriner Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9000 109th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11701 Goodrich Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12810 Virkler Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2700 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2701 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2730 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2801 Hutchison McDonald Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3000 Crosspoint Center Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3005 Crosspoint Center Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4045 Perimeter West Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4047 Perimeter West Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4525 Statesville Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4835 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4925 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5032 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5033 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5039 Sirona Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8910 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8916 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8924 Pioneer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2601 Indian River Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1540 S 54th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4650 Lake Forest Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4750 Lake Forest Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9645 Gerwig Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2550 John Glenn Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3800 Twin Creeks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 330 South Royal Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 455 Airline Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2130 Baldwin Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 329-333 Herrod Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1250 Hall Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1680 Executive Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1700 Executive Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2670 Breckinridge Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 170 Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 190 Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 265 Parkway East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 285 Parkway East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1000 Parliament Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4226 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4227 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4234 Surles Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4300 Emperor Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1957 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3169 Dodd Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3711 Kennebec Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 917 Lone Oak Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10301-10305 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10321 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10333 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10349-10357 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10365-10375 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10393-10394 West 70th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7075 Flying Cloud Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7078 Shady Oak Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1 Truman Drive South [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2250 Arthur Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6600 Business Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6675 Business Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7351 Coca Cola Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 21705-21707 Mississippi Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 27143 Elwood International Port Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1800 Donaldson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6880 Fairfield Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7000-7018 Fairfield Business [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10721 Jasmine Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2000 Southpointe Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1400 NW 65th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6500 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6501 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6600 NW 12th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9601 Cosner Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5410 - 5430 Northwest 33rd Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12601 Industry Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12641 Industry Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12681-12691 Pala Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 850 S Jupiter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2510 W Main Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4251 North Highway 121 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1150 Pleasant Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 25 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 45 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2011 Southtech Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2121 Southtech Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 800 Commerce Parkway West Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 110 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 140 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11835 Newgate Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11841 Newgate Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1560 Hunter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1575 Hunter Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7361 Coca Cola Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7460 New Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7462 New Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 500 McCarthy Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 600 Industrial Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7195 Grayson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7253 Grayson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12537 Cerise Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1010 Petersburg Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 785 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 805 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 825 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 845 Lindbergh Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4198 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4183 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4189 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4193 Eagle Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4328, 4336 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4344 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4380 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4388 Federal Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4475 Premier Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4500 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4501 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4523 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4524 Green Point Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9600 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Unit 5 Logix Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1000 South Loop West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10241 W Little York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10245 W Little York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10301 Round Up Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10305 Round Up Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1050 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10607 Haddington Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10735 West Little York Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10739 West Little York Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11201 Greens Crossing Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11220 Ella Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1283 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1287 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1291 N Post Oak Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1416 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1420 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 14200 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1424 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1428 N Sam Houston Parkway E [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 14300 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 14400 Hollister Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 15102 Sommermeyer St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 15150 Sommermeyer St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16330 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16420 West Hardy Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16445 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1646 Rankin Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1655 Townhurst Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16580 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16602 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16605 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1665 Townhurst Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16680 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16685 Air Center Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1755 Trans Central Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4301 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4401 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4501 S Pinemont Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5200 N. Sam Houston Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5250 N. Sam Houston Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5500 N. Sam Houston Parkway West [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8017 Pinemont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8272 El Rio Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8282 El Rio Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8301 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8303 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 850 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 860 Greens Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8801-19 & 8821-49 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8802-8824 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8825-8839 N Sam Houston Pkwy [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8850-8872 Fallbrook Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 16200 Central Green Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Cabot III UK1B01 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1011 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1035 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1549 W Glenlake Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 901 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 925 N Hilltop Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8241 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8242 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8246 Sandy Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1305 Chastain Road NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1325 Chastain Road NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3600 Cobb International Bld NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Unit 1 Bear Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 650 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 680 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1770 Interstate Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5801 Columbia Park Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11425 State Highway 225 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11503 State Highway 225 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1701 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1842 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1902 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 640 S State Road 39 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7528 Walker Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8301 Industrial Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8500 Willard Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7533 Industrial Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 100 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1001 Cedar Hollow Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12,14,16 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 14 Lee Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 18 Great Valley Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 311 Technology Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 425 Old Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 50 Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 60 Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 600 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 700 Chesterfield Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1169 Canton Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 65 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 75 Brookfield Oaks Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 126-132 Liberty Industrial Pkw [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 95-115 Liberty Industrial Pkwy [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11150 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11401 NW 134th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11450 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 456 International Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 21 S Middlesex Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4 S Middlesex Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 250 Moonachie Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 230 Moonachie Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 22750 Cactus Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 150 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 323 Park Knoll Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 324 Park Knoll Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 619 Distribution Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1879 Lamont Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 350 Winmeyer Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4000 E Airport Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1000 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10003 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10511 & 10611 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 10771 Palm Bay Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1090 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1600-1650 Central Florida Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1902 Cypress Lake Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2000 Park Oaks Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2202 Taft-Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2212 Taft Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2256 Taft-Vineland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2351 Investors Row [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2400 South Lake Orange Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2412 Sand Lake Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2416 Lake Orange Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6200 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6989 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6918 Presidents Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6923 Lee Vista Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7022 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7100 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7101 TPC Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7315 Kingspointe Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 851 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 950 Gills Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 29 Liberty Square [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9550 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3535 Gravel Springs Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9700 Satellite Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1 Crescent Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 201 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 351 Rouse Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4000 S 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4300 South 26th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4751 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4775 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8th & Walnut Streets [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2626 South 7th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 563 South 63rd Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1000 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1901 10th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1909 10th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3605 East Plano Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3701 East Plano Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 800 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 900 Klein Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9801 80th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 14630-14650 28th Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2920 Northwest Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5905 Trenton Lane North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6055 Nathan Lane North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1400 SW 6th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1405 SW 6th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1500 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1501 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1601 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1651 SW 5th Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2201-2215 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2250-2270 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2280-2300 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2301-2329 NW 30th Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3000 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3001-3037 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3012-3050 NW 25th Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 595 SW 13th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 601 SW 13th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 605 SW 16th Terrace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2459 Almond Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1221 N Alder Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1920 West Baseline Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 301 Hill Carter Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4101-4127 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4201-4261 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4263-4299 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4263F-N. Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4301-4335 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4337-4379 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4401-4445 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4447-4491 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4501-4549 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4551-4593 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4601-4643 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4645-4683 Carolina Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4717-4729 Eubank Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 510 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 520 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 530 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 540 Eastpark Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5600-5626 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5601-5659 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5650-5674 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5700 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5701-5799 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5900 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6000 Eastport Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6530 Judge Adams Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6532 Judge Adams Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 13098 George Weber Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 13220 Wilfred Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 13225 Brockton Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1070 Windham Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1550 Central Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1135 Aviation Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8715 Bollman Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8501 East Raintree Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1150 Gateway Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5555 12th Avenue East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5651 Innovation Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 12110 Champion Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9300 Old Scotland Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3990 Heritage Oak Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3654-3668 Swenson Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3701 Illinois Ave [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3950-3980 Swenson Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1501 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1527 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1551 102nd Avenue North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6900 Harbor View Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6920 Harbour View Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6950 Harbour View Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1516 Fryar Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3401-3409 Cragmont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3502 Riga Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3505 Cragmont Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 3608 Queen Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5250 Eagle Trail Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5501-5519 Pioneer Park Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5690-5694 Crenshaw Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8110 Anderson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8130 Anderson Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9020 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9110 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9203 King Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9319 Peach Palm Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9704 Solar Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 9945 Currie Davis Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1850 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1858 E Encanto Dr [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 475 W Vaughn St [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 921 South Park Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8313 West Pierce Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8591 West Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 8601 West Washington [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5111 S Royal Atlanta Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5151 S Royal Atlanta Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1100 17th Street NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2100 M Street NW [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1400 Powis Court [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1 Kings Hill Aveune [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 42 Kings Hill Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Liberty Square, Block 1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Liberty Square, Block 2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Liberty Square, Block 3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Liberty Square, Block 5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1400 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 300 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 400 Northpoint Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2935 West Corporate Lakes Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2945 West Corporate Lakes Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 43-47 Hintz Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11020 Holly Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1951 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1953 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2988 Green Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 125 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2727 London Groveport Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 120 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 130 Caliber Ridge Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4485 Premier Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5430 FAA Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 951 Valleyview Lane [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1200 Claybrick Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1801 South 16th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11440 NW 122 Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 11250 NW 122nd Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1500 S 71st Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 7205 W Buckeye Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 4701 League Island Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5800 Eastport Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 5800 Technology Boulevard [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1910 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 1930 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 2040 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6017 Southern Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | 6035 Southern Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Operating Properties [Member] | Minimum [Member] | Worcester 1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Depreciable life (years)	5 years
Development in Progress [Member]
Real Estate and Accumulated Depreciation [Line Items]
Initial Cost of Land				3,043,130
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,388,458
Land and Improvements				0
Building and Improvements				7,431,588
Gross Amount Carried at End of Period	$ 7,431,588			7,431,588
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,431,588
Development in Progress [Member] | 2250 East Bardin Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Arlington, TX
Encumbrances				0
Initial Cost of Land				4,754,659
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				24,262,394
Land and Improvements				0
Building and Improvements				29,017,052
Gross Amount Carried at End of Period	$ 29,017,052			29,017,052
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 29,017,052
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 350 N York Rd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Bensenville, IL
Encumbrances				0
Accumulated Depreciation	$ 0			0
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 100 Carolina Way [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Carlisle, PA
Encumbrances				0
Initial Cost of Land				10,830,187
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				21,472,109
Land and Improvements				0
Building and Improvements				32,302,296
Gross Amount Carried at End of Period	$ 32,302,296			32,302,296
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 32,302,296
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1955 TW Alexander Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Durham, NC
Encumbrances				0
Initial Cost of Land				758,503
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,481,188
Land and Improvements				0
Building and Improvements				8,239,691
Gross Amount Carried at End of Period	$ 8,239,691			8,239,691
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,239,691
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 650 Swedesford Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	King of Prussia, PA
Encumbrances				0
Initial Cost of Land				488,529
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,914,012
Land and Improvements				0
Building and Improvements				8,402,541
Gross Amount Carried at End of Period	$ 8,402,541			8,402,541
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,402,541
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 875 Maxham Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lithia Springs, GA
Encumbrances				0
Initial Cost of Land				445,493
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				11,272,084
Land and Improvements				0
Building and Improvements				11,717,577
Gross Amount Carried at End of Period	$ 11,717,577			11,717,577
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 11,717,577
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 11430 NW 122 Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Medley, FL
Encumbrances				0
Initial Cost of Land				5,790,968
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				8,969,067
Land and Improvements				0
Building and Improvements				14,760,035
Gross Amount Carried at End of Period	$ 14,760,035			14,760,035
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 14,760,035
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1075 King George Post Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Edison, NJ
Encumbrances				0
Initial Cost of Land				0
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				13,168,246
Land and Improvements				0
Building and Improvements				13,168,246
Gross Amount Carried at End of Period	$ 13,168,246			13,168,246
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,168,246
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1720 West 135th Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Gardena, CA
Encumbrances				0
Initial Cost of Land				7,423,389
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				12,948,990
Land and Improvements				0
Building and Improvements				20,372,379
Gross Amount Carried at End of Period	$ 20,372,379			20,372,379
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,372,379
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 2980 Green Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greer, SC
Encumbrances				0
Initial Cost of Land				16,338
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,441,655
Land and Improvements				0
Building and Improvements				5,457,993
Gross Amount Carried at End of Period	$ 5,457,993			5,457,993
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,457,993
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 7157 Ridge Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover, MD
Encumbrances				0
Initial Cost of Land				3,875,203
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,929,287
Land and Improvements				0
Building and Improvements				8,804,490
Gross Amount Carried at End of Period	$ 8,804,490			8,804,490
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,804,490
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1200 Claybrick Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Landover, MD
Encumbrances				0
Initial Cost of Land				6,876,500
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				942,883
Land and Improvements				0
Building and Improvements				7,819,383
Gross Amount Carried at End of Period	$ 7,819,383			7,819,383
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,819,383
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1806 Highway 146th South [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				1,055,035
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,838,576
Land and Improvements				0
Building and Improvements				2,893,611
Gross Amount Carried at End of Period	$ 2,893,611			2,893,611
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,893,611
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1814 Highway 146th South [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				1,420,014
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				433,719
Land and Improvements				0
Building and Improvements				1,853,733
Gross Amount Carried at End of Period	$ 1,853,733			1,853,733
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,853,733
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1302 Wharton Weems Blvd [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	LaPorte, TX
Encumbrances				0
Initial Cost of Land				4,378,890
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,263,432
Land and Improvements				0
Building and Improvements				6,642,322
Gross Amount Carried at End of Period	$ 6,642,322			6,642,322
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,642,322
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 8801 Congdon Hill Drive [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Mertztown, PA
Encumbrances				0
Initial Cost of Land				23,016,646
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				47,804,802
Land and Improvements				0
Building and Improvements				70,821,448
Gross Amount Carried at End of Period	$ 70,821,448			70,821,448
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 70,821,448
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1050 Constitution Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Philadelphia, PA
Encumbrances				0
Initial Cost of Land				1,969,501
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				37,458,724
Land and Improvements				0
Building and Improvements				39,428,225
Gross Amount Carried at End of Period	$ 39,428,225			39,428,225
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 39,428,225
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1500 S 71st Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Phoenix, AZ
Encumbrances				0
Initial Cost of Land				4,234,407
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,648,512
Land and Improvements				0
Building and Improvements				8,882,919
Gross Amount Carried at End of Period	$ 8,882,919			8,882,919
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,882,919
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 3929 Shutterfly Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				592,233
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,093,931
Land and Improvements				0
Building and Improvements				10,686,164
Gross Amount Carried at End of Period	$ 10,686,164			10,686,164
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,686,164
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 9724 Alabama Street [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	San Bernardino, CA
Encumbrances				0
Initial Cost of Land				4,140,486
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				8,367,860
Land and Improvements				0
Building and Improvements				12,508,346
Gross Amount Carried at End of Period	$ 12,508,346			12,508,346
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,508,346
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | 1870 W Rio Salado Parkway [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tempe, AZ
Encumbrances				0
Initial Cost of Land				2,272,702
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				42,762,030
Land and Improvements				0
Building and Improvements				45,034,732
Gross Amount Carried at End of Period	$ 45,034,732			45,034,732
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 45,034,732
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Development in Progress [Member] | Worcester 2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Worcester, UK
Encumbrances				0
Initial Cost of Land				3,172,249
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				9,054,991
Land and Improvements				0
Building and Improvements				12,227,240
Gross Amount Carried at End of Period	$ 12,227,240			12,227,240
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 12,227,240
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	0
Development in Progress [Member] | Total Development in Progress [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				0
Initial Cost of Land				90,555,062
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				287,916,950
Land and Improvements				0
Building and Improvements				378,472,011
Gross Amount Carried at End of Period	378,472,011			378,472,011
Accumulated Depreciation	0			0
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	378,472,011
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Mill Creek Road East Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Allentown, PA
Encumbrances				0
Initial Cost of Land				7,175,000
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				0
Land and Improvements				7,175,000
Building and Improvements				0
Gross Amount Carried at End of Period	$ 7,175,000			7,175,000
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 7,175,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 100 and 160 Dulty's Lane Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Burlington, NJ
Encumbrances				0
Initial Cost of Land				3,746,363
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				387,026
Land and Improvements				4,133,389
Building and Improvements				0
Gross Amount Carried at End of Period	$ 4,133,389			4,133,389
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,133,389
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 180 Dulty's Lane Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Burlington, NJ
Encumbrances				0
Initial Cost of Land				2,866,850
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				329,151
Land and Improvements				3,196,001
Building and Improvements				0
Gross Amount Carried at End of Period	$ 3,196,001			3,196,001
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,196,001
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 180 Dulty's Lane Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Butts County, GA
Encumbrances				0
Initial Cost of Land				2,866,568
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,926,717
Land and Improvements				4,793,285
Building and Improvements				0
Gross Amount Carried at End of Period	$ 4,793,285			4,793,285
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 4,793,285
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Camden Town Center Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Camden, NJ
Encumbrances				0
Initial Cost of Land				11,303,073
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				10,252,135
Land and Improvements				21,555,208
Building and Improvements				0
Gross Amount Carried at End of Period	$ 21,555,208			21,555,208
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,555,208
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 12912 Virkler Drive Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				208,646
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				88,354
Land and Improvements				297,000
Building and Improvements				0
Gross Amount Carried at End of Period	$ 297,000			297,000
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,010
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 297,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Shopton Ridge Business Park Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Charlotte, NC
Encumbrances				0
Initial Cost of Land				644,925
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,859,095
Land and Improvements				2,504,020
Building and Improvements				0
Gross Amount Carried at End of Period	$ 2,504,020			2,504,020
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,504,020
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Mountain Creek Business Park L [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dallas, TX
Encumbrances				0
Initial Cost of Land				7,984,928
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,022,735
Land and Improvements				13,007,663
Building and Improvements				0
Gross Amount Carried at End of Period	$ 13,007,663			13,007,663
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,007,663
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Holly Lane North Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dayton, MN
Encumbrances				0
Initial Cost of Land				889,205
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				181,612
Land and Improvements				1,070,817
Building and Improvements				0
Gross Amount Carried at End of Period	$ 1,070,817			1,070,817
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,070,817
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | French Lake Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Dayton/Rogers, MN
Encumbrances				0
Initial Cost of Land				13,513,632
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,385,459
Land and Improvements				20,899,091
Building and Improvements				0
Gross Amount Carried at End of Period	$ 20,899,091			20,899,091
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 20,899,091
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Flying Cloud Drive Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Eden Prairie, MN
Encumbrances				0
Initial Cost of Land				2,051,631
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,369,545
Land and Improvements				6,421,176
Building and Improvements				0
Gross Amount Carried at End of Period	$ 6,421,176			6,421,176
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,421,176
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Camelback 303 Business Center Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Goodyear, AZ
Encumbrances				0
Initial Cost of Land				16,857,556
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,352,280
Land and Improvements				21,209,836
Building and Improvements				0
Gross Amount Carried at End of Period	$ 21,209,836			21,209,836
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 21,209,836
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Pleasant Ridge Road Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Greensboro, NC
Encumbrances				0
Initial Cost of Land				564,535
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,976,650
Land and Improvements				3,541,185
Building and Improvements				0
Gross Amount Carried at End of Period	$ 3,541,185			3,541,185
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,541,185
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Ridge Road Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hanover, MD
Encumbrances				0
Initial Cost of Land				3,371,183
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				(583,887)
Land and Improvements				2,787,296
Building and Improvements				0
Gross Amount Carried at End of Period	$ 2,787,296			2,787,296
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,008
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,787,296
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Interwood Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				5,160,668
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				29,015
Land and Improvements				5,189,683
Building and Improvements				0
Gross Amount Carried at End of Period	$ 5,189,683			5,189,683
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,189,683
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Rankin Road Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				5,756,865
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				382,693
Land and Improvements				6,139,558
Building and Improvements				0
Gross Amount Carried at End of Period	$ 6,139,558			6,139,558
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,007
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,139,558
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Richey Road Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Houston, TX
Encumbrances				0
Initial Cost of Land				26,135,466
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				7,024,965
Land and Improvements				33,160,431
Building and Improvements				0
Gross Amount Carried at End of Period	$ 33,160,431			33,160,431
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 33,160,431
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Cabin Branch Road Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Hyattsville, MD
Encumbrances				0
Initial Cost of Land				507,337
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,099
Land and Improvements				510,436
Building and Improvements				0
Gross Amount Carried at End of Period	$ 510,436			510,436
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 510,436
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Frye Road and Valley View Lane Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Irving, TX
Encumbrances				0
Initial Cost of Land				1,917,440
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				962,176
Land and Improvements				2,879,616
Building and Improvements				0
Gross Amount Carried at End of Period	$ 2,879,616			2,879,616
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,879,616
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Kent County, UK [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Kent, UK
Encumbrances				0
Initial Cost of Land				0
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				35,246,308
Land and Improvements				35,246,308
Building and Improvements				0
Gross Amount Carried at End of Period	$ 35,246,308			35,246,308
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 35,246,308
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Port Crossing Commerce Center Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	La Porte, TX
Encumbrances				0
Initial Cost of Land				9,401,409
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,382,139
Land and Improvements				10,783,548
Building and Improvements				0
Gross Amount Carried at End of Period	$ 10,783,548			10,783,548
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,783,548
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Commodore Business Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Logan, NJ
Encumbrances				0
Initial Cost of Land				792,118
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				1,455,989
Land and Improvements				2,248,107
Building and Improvements				0
Gross Amount Carried at End of Period	$ 2,248,107			2,248,107
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	1,995
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 2,248,107
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Spring Creek Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Lower Macungie Twp, PA
Encumbrances				0
Initial Cost of Land				33,567,060
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				8,106,014
Land and Improvements				41,673,074
Building and Improvements				0
Gross Amount Carried at End of Period	$ 41,673,074			41,673,074
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 41,673,074
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 380 Old Morehall Road [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				1,344,809
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				0
Land and Improvements				1,344,809
Building and Improvements				0
Gross Amount Carried at End of Period	$ 1,344,809			1,344,809
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,012
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 1,344,809
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 6 Great Valley Parkway Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				603,050
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,598,259
Land and Improvements				3,201,309
Building and Improvements				0
Gross Amount Carried at End of Period	$ 3,201,309			3,201,309
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,015
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,201,309
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Old Morehall Rd Land (Morelli) [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Malvern, PA
Encumbrances				0
Initial Cost of Land				3,343,863
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				33,548
Land and Improvements				3,377,411
Building and Improvements				0
Gross Amount Carried at End of Period	$ 3,377,411			3,377,411
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,016
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,377,411
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Miami International Tradeport Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Medley, FL
Encumbrances				0
Initial Cost of Land				9,202,254
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				15,840,193
Land and Improvements				25,042,447
Building and Improvements				0
Gross Amount Carried at End of Period	$ 25,042,447			25,042,447
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 25,042,447
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 557 Nazareth Pike Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Nazareth, PA
Encumbrances				0
Initial Cost of Land				4,667,646
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				532,716
Land and Improvements				5,200,362
Building and Improvements				0
Gross Amount Carried at End of Period	$ 5,200,362			5,200,362
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 5,200,362
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Southern Boulevard Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Palm Beach County, FL
Encumbrances				0
Initial Cost of Land				8,051,351
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				5,160,487
Land and Improvements				13,211,838
Building and Improvements				0
Gross Amount Carried at End of Period	$ 13,211,838			13,211,838
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,014
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 13,211,838
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Buckeye Logistics Center West Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Phoenix, AZ
Encumbrances				0
Initial Cost of Land				6,173,841
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				4,014,937
Land and Improvements				10,188,778
Building and Improvements				0
Gross Amount Carried at End of Period	$ 10,188,778			10,188,778
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,013
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 10,188,778
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Woodlands Center Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Sandston, VA
Encumbrances				0
Initial Cost of Land				148,314
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				21,717
Land and Improvements				170,031
Building and Improvements				0
Gross Amount Carried at End of Period	$ 170,031			170,031
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	1,996
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 170,031
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Northsight Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Scottsdale, AZ
Encumbrances				0
Initial Cost of Land				6,176,464
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				2,204,597
Land and Improvements				8,381,061
Building and Improvements				0
Gross Amount Carried at End of Period	$ 8,381,061			8,381,061
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,005
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 8,381,061
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Suffolk Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Suffolk, VA
Encumbrances				0
Initial Cost of Land				2,715,714
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				823,895
Land and Improvements				3,539,609
Building and Improvements				0
Gross Amount Carried at End of Period	$ 3,539,609			3,539,609
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 3,539,609
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | 6119 W. Linebaugh Avenue [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				180,136
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				30,499
Land and Improvements				210,635
Building and Improvements				0
Gross Amount Carried at End of Period	$ 210,635			210,635
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,000
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 210,635
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0
Land Held for Development [Member] | Legacy Park Land [Member]
Real Estate and Accumulated Depreciation [Line Items]
Location	Tampa, FL
Encumbrances				0
Initial Cost of Land				3,289,423
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				3,168,809
Land and Improvements				6,458,232
Building and Improvements				0
Gross Amount Carried at End of Period	$ 6,458,232			6,458,232
Accumulated Depreciation	$ 0			0
Date of Construction or Acquisition	2,006
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	$ 6,458,232
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	0
Land Held for Development [Member] | Total Land Held for Development [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				0
Initial Cost of Land				203,179,323
Initial Cost of Buildings				0
Costs Capitalized Subsequent to Acquisition				127,568,927
Land and Improvements				330,748,250
Building and Improvements				0
Gross Amount Carried at End of Period	330,748,250			330,748,250
Accumulated Depreciation	0			$ 0
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real Estate, Gross	330,748,250
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real Estate Accumulated Depreciation	$ 0

Uncategorized Items - lry-20171

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 89,671,000
Liberty Property Limited Partnership [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 89,671,000