Gramercy Property Trust 10-Q 1 Nov 17 2017 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 27, 2017
Document Information [Line Items]
Entity Registrant Name	Gramercy Property Trust
Entity Central Index Key	1,297,587
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Trading Symbol	gpt
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		160,670,537
GPT Operating Partnership LP [Member]
Document Information [Line Items]
Entity Registrant Name	GPT Operating Partnership LP
Entity Central Index Key	1,708,204
Entity Filer Category	Non-accelerated Filer

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Real estate investments, at cost:
Land	$ 1,004,236	$ 805,264
Building and improvements	4,845,246	4,053,125
Less: accumulated depreciation	(297,448)	(201,525)
Total real estate investments, net	5,552,034	4,656,864
Cash and cash equivalents	68,018	67,529
Restricted cash	19,183	12,904
Investment in unconsolidated equity investments	73,163	101,807
Assets held for sale, net	17,292	0
Tenant and other receivables, net	75,264	72,795
Acquired lease assets, net of accumulated amortization of $201,010 and $133,710	625,771	618,680
Other assets	110,613	72,948
Total assets	6,541,338	5,603,527
Liabilities:
Senior unsecured revolving credit facility	615,097	65,837
Exchangeable senior notes, net	0	108,832
Mortgage notes payable, net	606,898	558,642
Total long-term debt, net	2,943,679	2,454,775
Accounts payable and accrued expenses	58,083	58,380
Dividends payable	61,486	53,074
Below market lease liabilities, net of accumulated amortization of $27,564 and $26,416	173,577	230,183
Liabilities related to assets held for sale	4,914	0
Other liabilities	53,993	46,081
Total liabilities	3,295,732	2,842,493
Commitments and contingencies
Noncontrolling interest in the Operating Partnership	75,139	8,643
Equity:
Common shares, par value $0.01, 160,669,468 and 140,647,971 issued and outstanding at September 30, 2017 and December 31, 2016, respectively	1,607	1,406
Additional paid-in-capital	4,407,953	3,887,793
Accumulated other comprehensive income (loss)	2,118	(4,128)
Accumulated deficit	(1,325,605)	(1,216,753)
Total shareholders' equity	3,170,467	2,752,712
Noncontrolling interest in other partnerships	0	(321)
Total equity	3,170,467	2,752,391
Partners’ Capital:
Accumulated other comprehensive loss	2,118	(4,128)
Total liabilities and equity	6,541,338	5,603,527
Series A Preferred Stock [Member]
Equity:
Series A cumulative redeemable preferred shares, par value $0.01, liquidation preference $87,500, and 3,500,000 shares authorized, issued and outstanding at September 30, 2017 and December 31, 2016	84,394	84,394
Senior unsecured notes, net [Member]
Liabilities:
Unsecured debt	496,684	496,464
Senior unsecured term loans [Member]
Liabilities:
Unsecured debt	1,225,000	1,225,000
GPT Operating Partnership LP [Member]
Real estate investments, at cost:
Land	1,004,236	805,264
Building and improvements	4,845,246	4,053,125
Less: accumulated depreciation	(297,448)	(201,525)
Total real estate investments, net	5,552,034	4,656,864
Cash and cash equivalents	68,018	67,529
Restricted cash	19,183	12,904
Investment in unconsolidated equity investments	73,163	101,807
Assets held for sale, net	17,292	0
Tenant and other receivables, net	75,264	72,795
Acquired lease assets, net of accumulated amortization of $201,010 and $133,710	625,771	618,680
Other assets	110,613	72,948
Total assets	6,541,338	5,603,527
Liabilities:
Senior unsecured revolving credit facility	615,097	65,837
Exchangeable senior notes, net	0	108,832
Mortgage notes payable, net	606,898	558,642
Total long-term debt, net	2,943,679	2,454,775
Accounts payable and accrued expenses	58,083	58,380
Dividends payable	61,486	53,074
Below market lease liabilities, net of accumulated amortization of $27,564 and $26,416	173,577	230,183
Liabilities related to assets held for sale	4,914	0
Other liabilities	53,993	46,081
Total liabilities	3,295,732	2,842,493
Commitments and contingencies
Noncontrolling interest in the Operating Partnership	75,139	8,643
Equity:
Accumulated other comprehensive income (loss)	2,118	(4,128)
Partners’ Capital:
Series A cumulative redeemable preferred units, liquidation preference $87,500, and 3,500,000 units issued and outstanding at September 30, 2017 and December 31, 2016	84,394	84,394
GPT partners’ capital (1,634,559 and 1,412,916 general partner common units and 158,689,729 and 139,235,055 limited partner common units outstanding at September 30, 2017 and December 31, 2016, respectively)	3,083,955	2,672,446
Accumulated other comprehensive loss	2,118	(4,128)
Total GPTOP partners' capital	3,170,467	2,752,712
Noncontrolling interest in other partnerships	0	(321)
Total partners’ capital	3,170,467	2,752,391
Total liabilities and equity	6,541,338	5,603,527
GPT Operating Partnership LP [Member] | Senior unsecured notes, net [Member]
Liabilities:
Unsecured debt	496,684	496,464
GPT Operating Partnership LP [Member] | Senior unsecured term loans [Member]
Liabilities:
Unsecured debt	$ 1,225,000	$ 1,225,000

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Acquired lease assets, accumulated amortization (in dollars)	$ 201,010	$ 133,710
Below market lease liabilities, accumulated amortization (in dollars)	$ 27,564	$ 26,416
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares issued	160,669,468	140,647,971
Common stock, shares outstanding	160,669,468	140,647,971
Cumulative redeemable preferred stock, shares authorized	10,000,000	10,000,000
Cumulative redeemable preferred stock, shares outstanding	3,500,000
Series A Preferred Stock [Member]
Cumulative redeemable preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Cumulative redeemable preferred stock, liquidation preference (in dollars)	$ 87,500	$ 87,500
Cumulative redeemable preferred stock, shares authorized	3,500,000	3,500,000
Cumulative redeemable preferred stock, shares issued	3,500,000	3,500,000
Cumulative redeemable preferred stock, shares outstanding	3,500,000	3,500,000
GPT Operating Partnership LP [Member]
Acquired lease assets, accumulated amortization (in dollars)	$ 201,010	$ 133,710
Below market lease liabilities, accumulated amortization (in dollars)	27,564	26,416
Series A cumulative redeemable preferred units, liquidation preference (in dollars)	$ 87,500	$ 87,500
Series A cumulative redeemable preferred units, units issued	3,500,000	3,500,000
Series A cumulative redeemable preferred units, units outstanding	3,500,000	3,500,000
General partners' capital, units issued	1,634,559	1,412,916
Limited partners' capital, units issued	158,689,729	139,235,055
General partners' capital, units outstanding	1,634,559	1,412,916
Limited partners' capital, units outstanding	158,689,729	139,235,055
Noncontrolling Interest [Member] | GPT Operating Partnership LP [Member]
Limited partners' capital, units outstanding	3,131,636	643,596

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues
Rental revenue	$ 110,174	$ 100,847	$ 321,717	$ 291,459
Third-party management fees	2,057	7,172	8,287	30,528
Operating expense reimbursements	21,384	21,231	61,380	65,718
Other income	1,240	1,842	4,830	3,357
Total revenues	134,855	131,092	396,214	391,062
Operating Expenses
Property operating expenses	24,844	22,685	71,249	70,364
Property management expenses	3,252	4,810	8,771	14,922
Depreciation and amortization	66,761	62,863	191,154	181,649
General and administrative expenses	9,638	8,165	27,494	23,892
Acquisition expenses	0	1,272	0	5,994
Total operating expenses	104,495	99,795	298,668	296,821
Operating Income	30,360	31,297	97,546	94,241
Other Expenses:
Interest expense	(24,266)	(18,409)	(70,561)	(57,271)
Other-than-temporary impairment	0	0	(4,081)	0
Portion of impairment recognized in other comprehensive loss	0	0	(809)	0
Net impairment recognized in earnings	0	0	(4,890)	0
Equity in net income (loss) of unconsolidated equity investments	48,730	(1,138)	48,884	(4,061)
Gain on dissolution of previously held U.S. unconsolidated equity investment interests	0	0	0	7,229
Loss on extinguishment of debt	(6,751)	(13,777)	(6,691)	(20,890)
Impairment of real estate investments	(3,064)	(1,053)	(21,415)	(1,053)
Income (loss) from continuing operations before provision for taxes	45,009	(3,080)	42,873	18,195
Provision for taxes	598	(331)	647	(3,734)
Income (loss) from continuing operations	45,607	(3,411)	43,520	14,461
Income (loss) from discontinued operations before gain on extinguishment of debt	(24)	347	(76)	3,115
Gain on extinguishment of debt	0	0	0	1,930
Income (loss) from discontinued operations	(24)	347	(76)	5,045
Net income (loss) before net gain on disposals	45,583	(3,064)	43,444	19,506
Net gain on disposals	4,879	2,336	24,258	2,336
Gain on sale of European unconsolidated equity investment interests held with a related party	0	0	0	5,341
Net Income (loss)	50,462	(728)	67,702	27,183
Net income attributable to noncontrolling interest	(333)	(221)	(374)	(152)
Net income (loss) attributable to Gramercy Property Trust	50,129	(949)	67,328	27,031
Preferred share dividends	(1,559)	(1,559)	(4,676)	(4,676)
Net Income (loss) available to common shareholders	$ 48,570	$ (2,508)	$ 62,652	$ 22,355
Basic earnings per share:
Net income from continuing operations, after preferred dividends (in usd per share)	$ 0.32	$ (0.02)	$ 0.42	$ 0.11
Net income (loss) from discontinued operations (in usd per share)	0	0	0	0.04
Net income available to common stockholders (in usd per share)	0.32	(0.02)	0.42	0.15
Diluted earnings per share:
Net income from continuing operations, after preferred dividends (in usd per share)	0.32	(0.02)	0.42	0.11
Net income (loss) from discontinued operations (in usd per share)	0	0	0	0.04
Net income available to common stockholders (in usd per share)	$ 0.32	$ (0.02)	$ 0.42	$ 0.15
Basic weighted average common shares outstanding (in shares)	152,619,352	140,257,503	147,399,457	141,180,822
Diluted weighted average common shares and common share equivalents outstanding (in shares)	157,507,213	140,257,503	147,430,882	142,387,709
GPT Operating Partnership LP [Member]
Revenues
Rental revenue	$ 110,174	$ 100,847	$ 321,717	$ 291,459
Third-party management fees	2,057	7,172	8,287	30,528
Operating expense reimbursements	21,384	21,231	61,380	65,718
Other income	1,240	1,842	4,830	3,357
Total revenues	134,855	131,092	396,214	391,062
Operating Expenses
Property operating expenses	24,844	22,685	71,249	70,364
Property management expenses	3,252	4,810	8,771	14,922
Depreciation and amortization	66,761	62,863	191,154	181,649
General and administrative expenses	9,638	8,165	27,494	23,892
Acquisition expenses	0	1,272	0	5,994
Total operating expenses	104,495	99,795	298,668	296,821
Operating Income	30,360	31,297	97,546	94,241
Other Expenses:
Interest expense	(24,266)	(18,409)	(70,561)	(57,271)
Other-than-temporary impairment	0	0	(4,081)	0
Portion of impairment recognized in other comprehensive loss	0	0	(809)	0
Net impairment recognized in earnings	0	0	(4,890)	0
Equity in net income (loss) of unconsolidated equity investments	48,730	(1,138)	48,884	(4,061)
Gain on dissolution of previously held U.S. unconsolidated equity investment interests	0	0	0	7,229
Loss on extinguishment of debt	(6,751)	(13,777)	(6,691)	(20,890)
Impairment of real estate investments	(3,064)	(1,053)	(21,415)	(1,053)
Income (loss) from continuing operations before provision for taxes	45,009	(3,080)	42,873	18,195
Provision for taxes	598	(331)	647	(3,734)
Income (loss) from continuing operations	45,607	(3,411)	43,520	14,461
Income (loss) from discontinued operations before gain on extinguishment of debt	(24)	347	(76)	3,115
Gain on extinguishment of debt	0	0	0	1,930
Income (loss) from discontinued operations	(24)	347	(76)	5,045
Net income (loss) before net gain on disposals	45,583	(3,064)	43,444	19,506
Net gain on disposals	4,879	2,336	24,258	2,336
Gain on sale of European unconsolidated equity investment interests held with a related party	0	0	0	5,341
Net Income (loss)	50,462	(728)	67,702	27,183
Net (income) loss attributable to noncontrolling interest in other partnerships	97	(229)	114	(90)
Net income (loss) attributable to Gramercy Property Trust	50,559	(957)	67,816	27,093
Preferred share dividends	(1,559)	(1,559)	(4,676)	(4,676)
Net income (loss) available to common unitholders	$ 49,000	$ (2,516)	$ 63,140	$ 22,417
Basic earnings per unit:
Net income from continuing operations, after preferred unit distributions basic (in usd per unit)	$ 0.32	$ (0.02)	$ 0.42	$ 0.11
Net income (loss) from discontinued operations, basic (in usd per unit)	0	0	0	0.04
Net income available to common unitholders, basic (in usd per unit)	0.32	(0.02)	0.42	0.15
Diluted earnings per unit:
Net income from continuing operations, after preferred unit distributions, diluted (in usd per unit)	0.32	(0.02)	0.42	0.11
Net income (loss) from discontinued operations, diluted (in usd per unit)	0	0	0	0.04
Net income available to common unitholders, diluted (in usd per unit)	$ 0.32	$ (0.02)	$ 0.42	$ 0.15
Basic weighted average common units outstanding (in units)	153,971,961	140,596,612	148,248,795	141,580,593
Diluted weighted average common units outstanding (in units)	158,859,822	140,596,612	148,280,220	142,387,709

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Income (loss)	$ 50,462	$ (728)	$ 67,702	$ 27,183
Other comprehensive income (loss):
Unrealized loss on available for sale debt securities	(633)	(1,426)	(2,202)	(459)
Unrealized gain (loss) on derivative instruments	2,959	7,653	4,645	(25,996)
Reclassification of accumulated foreign currency translation adjustments due to disposal	(1,362)	0	(1,362)	(3,737)
Reclassification of unrealized gain of non-derivative net investment hedge into earnings	1,851	0	1,851	0
Reclassification of unrealized gain on terminated derivative instruments into earnings	273	282	812	913
Foreign currency translation adjustments	673	(1,120)	2,465	(3,687)
Other comprehensive income (loss)	3,761	5,389	6,209	(32,966)
Comprehensive income (loss)	54,223	4,661	73,911	(5,783)
Net income attributable to noncontrolling interest	(333)	(221)	(374)	(152)
Other comprehensive (income) loss attributable to noncontrolling interest	45	(13)	59	102
Comprehensive income (loss) attributable to Gramercy Property Trust	53,935	4,427	73,596	(5,833)
GPT Operating Partnership LP [Member]
Net Income (loss)	50,462	(728)	67,702	27,183
Other comprehensive income (loss):
Unrealized loss on available for sale debt securities	(633)	(1,426)	(2,202)	(459)
Unrealized gain (loss) on derivative instruments	2,959	7,653	4,645	(25,996)
Reclassification of accumulated foreign currency translation adjustments due to disposal	(1,362)	0	(1,362)	(3,737)
Reclassification of unrealized gain of non-derivative net investment hedge into earnings	1,851	0	1,851	0
Reclassification of unrealized gain on terminated derivative instruments into earnings	273	282	812	913
Foreign currency translation adjustments	673	(1,120)	2,465	(3,687)
Other comprehensive income (loss)	3,761	5,389	6,209	(32,966)
Comprehensive income (loss)	54,223	4,661	73,911	(5,783)
Net (income) loss attributable to noncontrolling interest in other partnerships	97	(229)	114	(90)
Other comprehensive (income) loss attributable to noncontrolling interest	12	0	37	0
Comprehensive income (loss) attributable to Gramercy Property Trust	$ 54,332	$ 4,432	$ 74,062	$ (5,873)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Shareholders' Equity (Deficit) and Noncontrolling Interests - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	Total Gramercy Property Trust [Member]	Common Shares [Member]	Preferred Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings/(Accumulated Deficit) [Member]	Noncontrolling Interest [Member]
Balance (in shares) at Dec. 31, 2016	140,647,971		140,647,971
Balance at Dec. 31, 2016	$ 2,752,391	$ 2,752,712	$ 1,406	$ 84,394	$ 3,887,793	$ (4,128)	$ (1,216,753)	$ (321)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (loss)	67,214	67,328					67,328	(114)
Change in net unrealized gain on derivative instruments	4,645	4,645				4,645
Change in net unrealized loss on debt securities	(2,202)	(2,202)				(2,202)
Reclassification of unrealized gain on terminated derivative instruments into earnings	812	812				812
Offering costs	(14,137)	(14,137)			(14,137)
Issuance of shares (in shares)			14,569,978
Issuance of shares	410,585	410,585	$ 146		410,439
Issuance of shares - redemption of Exchangeable Senior Notes for common shares (in shares)			5,258,420
Issuance of shares - redemption of Exchangeable Senior Notes for common shares	117,450	117,450	$ 53		117,397
Share based compensation - fair value (in shares)			80,142
Share based compensation - fair value	$ 4,516	4,516	$ 1		4,515
Dividend reinvestment program proceeds (in shares)	5,410		5,410
Dividend reinvestment program proceeds	$ 151	151			151
Conversion of OP Units to commons shares (in shares)			107,547
Conversion of OP Units to common shares	2,987	2,987	$ 1		2,986
Reallocation of noncontrolling interest in the Operating Partnership	(1,191)	(1,191)			(1,191)
Reclassification of accumulated foreign currency translation adjustments due to disposal	(1,362)
Reclassification of unrealized gain of non-derivative net investment hedge into earnings	1,851
Foreign currency translation adjustment	2,465	2,502				2,502		(37)
Contributions to noncontrolling interest in other partnerships	472							472
Dividends on preferred shares	(4,676)	(4,676)					(4,676)
Dividends on common shares	$ (171,504)	(171,504)					(171,504)
Balance (in shares) at Sep. 30, 2017	160,669,468		160,669,468
Balance at Sep. 30, 2017	$ 3,170,467	$ 3,170,467	$ 1,607	$ 84,394	$ 4,407,953	$ 2,118	$ (1,325,605)	$ 0

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Partners' Capital - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	GPT Operating Partnership LP [Member]	GPT Operating Partnership LP [Member]Total GPTOP [Member]	GPT Operating Partnership LP [Member]Partners' Interest [Member]	GPT Operating Partnership LP [Member]Series A Preferred Units [Member]	GPT Operating Partnership LP [Member]Accumulated Other Comprehensive Income (Loss) [Member]	GPT Operating Partnership LP [Member]Noncontrolling Interest [Member]	Exchangeable Senior Notes [Member]GPT Operating Partnership LP [Member]	Exchangeable Senior Notes [Member]GPT Operating Partnership LP [Member]Total GPTOP [Member]	Exchangeable Senior Notes [Member]GPT Operating Partnership LP [Member]Partners' Interest [Member]
Beginning balance (in units) at Dec. 31, 2016				140,647,971
Beginning balance at Dec. 31, 2016		$ 2,752,391	$ 2,752,712	$ 2,672,446	$ 84,394	$ (4,128)	$ (321)
Increase (Decrease) in Partners' Capital [Roll Forward]
Net Income (loss)	$ 67,214	67,214	67,328	67,328			(114)
Change in net unrealized gain on derivative instruments	4,645	4,645	4,645			4,645
Change in net unrealized loss on debt securities	(2,202)	(2,202)	(2,202)			(2,202)
Reclassification of unrealized gain on terminated derivative instruments into earnings	812	812	812			812
Offering costs		(14,137)	(14,137)	$ (14,137)
Issuance of common units resulting from public issuance of common shares (in units)				14,569,978
Issuance of common units resulting from public issuance of common shares		410,585	410,585	$ 410,585
Share based compensation - fair value (in units)				80,142
Share based compensation - fair value		4,516	4,516	$ 4,516
Distribution reinvestment program proceeds (in units)				5,410
Distribution reinvestment program proceeds		151	151	$ 151
Conversion of OP Units to common unit (in units)				107,547						5,258,420
Conversion of OP Units to common units		2,987	2,987	$ 2,987				$ 117,450	$ 117,450	$ 117,450
Reallocation of noncontrolling interest in the Operating Partnership	(1,191)	(1,191)	(1,191)	(1,191)
Reclassification of accumulated foreign currency translation adjustments due to disposal	(1,362)	(1,362)
Reclassification of unrealized gain of non-derivative net investment hedge into earnings	1,851	1,851
Foreign currency translation adjustment	2,465	2,465	2,502			2,502	(37)
Contributions to noncontrolling interest in other partnerships	$ 472	472					$ 472
Distributions on preferred units		(4,676)	(4,676)	(4,676)
Distributions on common units		$ (171,504)	(171,504)	$ (171,504)
Ending balance (in units) at Sep. 30, 2017		160,324,288		160,669,468			3,131,636
Ending balance at Sep. 30, 2017		$ 3,170,467	$ 3,170,467	$ 3,083,955	$ 84,394	$ 2,118	$ 0

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net income	$ 67,702	$ 27,183
Adjustments to net cash provided by operating activities:
Depreciation and amortization	191,154	181,649
Amortization of acquired leases to rental revenue and expense	(4,540)	(10,332)
Amortization of deferred costs	1,858	1,177
Amortization of discounts and other fees	17	(3,636)
Amortization of lease inducement costs	285	259
Straight-line rent adjustment	(22,441)	(19,084)
Other-than-temporary impairment on retained bonds	4,890	0
Impairment of real estate investments	21,415	1,053
Net gain on disposals	(24,258)	(2,336)
Distributions received from unconsolidated equity investments	9,205	48,235
Equity in net (income) loss of unconsolidated equity investments	(48,884)	4,061
Gain on remeasurement of previously held unconsolidated equity investment interests	0	(7,229)
Gain from sale of unconsolidated equity investment interests held with a related party	0	(5,341)
Loss on extinguishment of debt	6,691	18,960
Amortization of share-based compensation	6,051	3,704
Changes in operating assets and liabilities:
Restricted cash	(628)	1,765
Payment of capitalized leasing costs	(7,491)	(11,910)
Tenant and other receivables	18,510	(19,890)
Other assets	(39,168)	(16,660)
Accounts payable and accrued expenses	(1,211)	(16,945)
Other liabilities	8,509	(8,446)
Net cash provided by operating activities	187,666	166,237
Investing Activities:
Capital expenditures	(64,454)	(18,711)
Distributions from investing activities received from unconsolidated equity investments	87,229	84,588
Proceeds from sales of unconsolidated equity investment interests held with a related party	9,644	148,884
Proceeds from sale of real estate	228,135	860,783
Return of restricted cash held in escrow for 1031 exchange	0	(157,347)
Contributions to unconsolidated equity investments	(20,775)	(33,632)
Acquisition of real estate	(1,129,897)	(540,596)
Restricted cash for tenant improvements	(4,491)	10,560
Proceeds from servicing advances receivable	0	1,390
Net cash provided by (used in) investing activities	(894,609)	355,919
Financing Activities:
Proceeds from unsecured term loan and credit facility	805,000	306,466
Proceeds from senior unsecured notes	0	50,000
Repayment of unsecured term loans and credit facility	(261,818)	(440,000)
Acquisition of treasury bonds for defeasance	0	(144,063)
Proceeds from mortgage notes payable	2,582	9,550
Repayment of mortgage notes payable	(61,722)	(251,266)
Offering costs	(14,137)	(105)
Proceeds from sale of common shares	410,736	0
Payments for taxes related to net share settlement of equity awards	(1,855)	0
Payment of deferred financing costs	(1,719)	(1,734)
Payment of debt extinguishment costs	0	(15,868)
Preferred share dividends paid	(4,676)	(4,676)
Common share dividends paid	(163,903)	(101,804)
Proceeds from exercise of share options and purchases under the employee share purchase plan	0	167
Contributions from noncontrolling interests in other entities	472	0
Distribution to noncontrolling interest in the Operating Partnership	(286)	(303)
Change in restricted cash from financing activities	(1,192)	(62)
Net cash provided by (used in) financing activities	707,482	(593,698)
Net increase (decrease) in cash and cash equivalents	539	(71,542)
Decrease in cash and cash equivalents related to foreign currency translation	(50)	(137)
Cash and cash equivalents at beginning of period	67,529	128,031
Cash and cash equivalents at end of period	68,018	56,352
GPT Operating Partnership LP [Member]
Operating Activities:
Net income	67,702	27,183
Adjustments to net cash provided by operating activities:
Depreciation and amortization	191,154	181,649
Amortization of acquired leases to rental revenue and expense	(4,540)	(10,332)
Amortization of deferred costs	1,858	1,177
Amortization of discounts and other fees	17	(3,636)
Amortization of lease inducement costs	285	259
Straight-line rent adjustment	(22,441)	(19,084)
Other-than-temporary impairment on retained bonds	4,890	0
Impairment of real estate investments	21,415	1,053
Net gain on disposals	(24,258)	(2,336)
Distributions received from unconsolidated equity investments	9,205	48,235
Equity in net (income) loss of unconsolidated equity investments	(48,884)	4,061
Gain on remeasurement of previously held unconsolidated equity investment interests	0	(7,229)
Gain from sale of unconsolidated equity investment interests held with a related party	0	(5,341)
Loss on extinguishment of debt	6,691	18,960
Amortization of share-based compensation	6,051	3,704
Other non-cash adjustments	0	0
Changes in operating assets and liabilities:
Restricted cash	(628)	1,765
Payment of capitalized leasing costs	(7,491)	(11,910)
Tenant and other receivables	18,510	(19,890)
Other assets	(39,168)	(16,660)
Accounts payable and accrued expenses	(1,211)	(16,945)
Other liabilities	8,509	(8,446)
Net cash provided by operating activities	187,666	166,237
Investing Activities:
Capital expenditures	(64,454)	(18,711)
Distributions from investing activities received from unconsolidated equity investments	87,229	84,588
Proceeds from sales of unconsolidated equity investment interests held with a related party	9,644	148,884
Proceeds from sale of real estate	228,135	860,783
Return of restricted cash held in escrow for 1031 exchange	0	(157,347)
Contributions to unconsolidated equity investments	(20,775)	(33,632)
Acquisition of real estate	(1,129,897)	(540,596)
Restricted cash for tenant improvements	(4,491)	10,560
Proceeds from servicing advances receivable	0	1,390
Net cash provided by (used in) investing activities	(894,609)	355,919
Financing Activities:
Proceeds from unsecured term loan and credit facility	805,000	306,466
Proceeds from senior unsecured notes	0	50,000
Repayment of unsecured term loans and credit facility	(261,818)	(440,000)
Acquisition of treasury bonds for defeasance	0	(144,063)
Proceeds from mortgage notes payable	2,582	9,550
Repayment of mortgage notes payable	(61,722)	(251,266)
Offering costs	(14,137)	(105)
Proceeds from sale of common shares	410,736	0
Payments for taxes related to net share settlement of equity awards	(1,855)	0
Payment of deferred financing costs	(1,719)	(1,734)
Payment of debt extinguishment costs	0	(15,868)
Preferred share dividends paid	(4,676)	(4,676)
Common share dividends paid	(163,903)	(101,804)
Proceeds from exercise of share options and purchases under the employee share purchase plan	0	167
Contributions from noncontrolling interests in other entities	472	0
Distribution to noncontrolling interest in the Operating Partnership	(286)	(303)
Change in restricted cash from financing activities	(1,192)	(62)
Net cash provided by (used in) financing activities	707,482	(593,698)
Net increase (decrease) in cash and cash equivalents	539	(71,542)
Decrease in cash and cash equivalents related to foreign currency translation	(50)	(137)
Cash and cash equivalents at beginning of period	67,529	128,031
Cash and cash equivalents at end of period	$ 68,018	$ 56,352

Business and Organization

Business and Organization	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Organization	Business and Organization Gramercy Property Trust, or the Company or Gramercy, a Maryland real estate investment trust, or REIT, together with its subsidiary, GPT Operating Partnership LP, or the Operating Partnership, is a leading global investor and asset manager of commercial real estate. Gramercy specializes in acquiring and managing high quality, income producing commercial real estate leased to high quality tenants in major markets in the United States and Europe. Gramercy earns revenues primarily through rental revenues on properties that it owns in the United States. The Company also owns unconsolidated equity investments in the United States, Europe, and Asia. The Company's operations are conducted primarily through the Operating Partnership. As of September 30, 2017 , third-party holders of limited partnership interests owned approximately 1.92% of the Operating Partnership. These interests are referred to as the noncontrolling interests in the Operating Partnership. As of September 30, 2017 , the Company’s wholly-owned portfolio consists of 367 properties comprising 81,046,993 rentable square feet with 97.4% occupancy. As of September 30, 2017 , the Company has ownership interests in 14 properties which are held in unconsolidated equity investments in the United States and Europe and one property held through the investment in CBRE Strategic Partners Asia. As of September 30, 2017 , the Company manages approximately $1,622,000 of commercial real estate assets, including approximately $1,305,000 of assets in Europe, which includes the increase in value due to the European investment sales in July 2017, discussed below. In July 2017, a private real estate investment fund that targeted single-tenant industrial, office and specialty retail assets throughout Europe and in which the Company owned a 14.2% interest, or the Gramercy European Property Fund, sold 100.0% of its assets and, concurrently, the Company sold its 5.1% interest in another European investment in real estate assets, or the Goodman Europe JV. The transactions resulted in net distributions to the Company of approximately $101,930 ( €89,366 ), inclusive of a promoted interest distribution of approximately $8,515 ( €7,448 ). During the nine months ended September 30, 2017 , the Company acquired 74 properties aggregating 18,361,835 square feet for a total purchase price of approximately $1,321,886 , including the acquisition of a previously consolidated variable interest entity, or VIE, for $29,605 , a vacant property for $2,400 , two land parcels for $6,840 , and one build-to-suit property upon completion for $63,244 . Additionally, during the nine months ended September 30, 2017 , the Company acquired two land parcels for an aggregate purchase price of $2,800 , on which it has committed to construct industrial facilities for an estimated $49,077 . During the nine months ended September 30, 2017 , the Company sold 25 properties and two offices from another asset aggregating 2,358,928 square feet for total gross proceeds of approximately $256,828 . Prior to December 17, 2015, the Company was known as Chambers Street Properties, or Chambers. On December 17, 2015, Chambers completed a merger, or the Merger, with Gramercy Property Trust Inc., or Legacy Gramercy. While Chambers was the surviving legal entity, immediately following consummation of the Merger, the Company changed its name to “Gramercy Property Trust” and its New York Stock Exchange, or NYSE, trading symbol to “GPT.” Unless the context requires otherwise, all references to “Company,” “Gramercy,” "we," "our" and "us" mean Legacy Gramercy and its subsidiaries, including Legacy Gramercy’s operating partnership and its subsidiaries, for the periods prior to the Merger closing and Gramercy Property Trust and its subsidiaries, including the Operating Partnership and its consolidated subsidiaries, for periods following the Merger closing.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Quarterly Presentation The accompanying Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In management’s opinion, all adjustments (consisting of normal recurring accruals) considered necessary for fair presentation have been included. The 2017 operating results for the period presented are not necessarily indicative of the results that may be expected for the year ending December 31, 2017 . These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 and in the Operating Partnership’s audited financial statements for the year ended December 31, 2016 filed as an exhibit to the Company’s Form 8-K filed on June 29, 2017. The Condensed Consolidated Balance Sheets at December 31, 2016 were derived from the audited Consolidated Financial Statements at that date. Reclassifications Certain prior year balances have been reclassified to conform with the current year presentation. These reclassifications had no effect on the previously reported net income. On the Condensed Consolidated Statements of Operations, the Company reclassified investment income of $544 and $1,490 for the three and nine months ended September 30, 2016 , respectively, into other income. Principles of Consolidation The Condensed Consolidated Financial Statements include the Company’s accounts and those of the Company’s subsidiaries which are wholly-owned or controlled by the Company, or entities which are VIEs in which the Company is the primary beneficiary. The primary beneficiary is the party that absorbs a majority of the VIE’s anticipated losses and/or a majority of the expected returns. The Company has evaluated its investments for potential classification as variable interests by evaluating the sufficiency of each entity’s equity investment at risk to absorb losses. Entities which the Company does not control and are considered VIEs, but where the Company is not the primary beneficiary, are accounted for under the equity method. All significant intercompany balances and transactions have been eliminated. The equity interests of other limited partners in the Company’s Operating Partnership are reflected as noncontrolling interests. See Note 13 for more information on the Company’s noncontrolling interests. Real Estate Investments Real Estate Acquisitions In January 2017, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2017-01, Amendments to Business Combinations, which clarifies the framework for determining whether an integrated set of assets and activities meets the definition of a business. The revised framework narrows the definition of a business, which is expected to result in fewer transactions being accounted for as business combinations. Acquisitions of integrated sets of assets and activities that do not meet the definition of a business are accounted for as asset acquisitions. Although the Company is not required to implement ASU 2017-01 until annual periods beginning after December 15, 2017, including interim periods within those periods, the Company early adopted the new standard in the first quarter of 2017. As a result, the Company evaluated its real estate acquisitions during the nine months ended September 30, 2017 under the new framework and determined the properties acquired did not meet the definition of a business, thus the transactions were accounted for as asset acquisitions. Refer to the "Recently Issued Accounting Pronouncements" section below for more information on the new guidance and refer to Note 4 for more information on the transactions during the nine months ended September 30, 2017 . The Company evaluates its acquisitions of real estate, including equity interests in entities that predominantly hold real estate assets, to determine if the acquired assets meet the definition of a business and need to be accounted for as a business combination, or alternatively, should be accounted for as an asset acquisition. An integrated set of assets and activities acquired does not meet the definition of a business if either (i) substantially all the fair value of the gross assets acquired is concentrated in either a single identifiable asset or a group of similar identifiable assets, or (ii) the asset and activities acquired do not contain at least an input and a substantive process that together significantly contribute to the ability to create outputs. The Company expects that its acquisitions of real estate will continue to not meet the revised definition of a business. Acquisitions of real estate that do not meet the definition of a business, including sale-leaseback transactions that have newly-originated leases and real estate investments under construction, or build-to-suit investments, are recorded as asset acquisitions. The accounting for asset acquisitions is similar to the accounting for business combinations, except that the acquisition consideration, including acquisition costs, is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. Based on this allocation methodology, asset acquisitions do not result in the recognition of goodwill or a bargain purchase. The Company incurs internal transaction costs, which are direct, incremental internal costs related to acquisitions, that are recorded within general and administrative expense. Additionally, for build-to-suit investments in which the Company may engage a developer to construct a property or provide funds to a tenant to develop a property, the Company capitalizes the funds provided to the developer/tenant and real estate taxes, if applicable, during the construction period. To determine the fair value of assets acquired and liabilities assumed in an acquisition, which generally include land, building, improvements, and intangibles, such as the value of above- and below-market leases and origination costs associated with the in-place leases at the acquisition date, the Company utilizes various estimates, processes and information to determine the as-if-vacant property value. Estimates of value are made using customary methods, including data from appraisals, comparable sales, and discounted cash flow analyses. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends, and market/economic conditions that may affect the property. The Company assesses the fair value of leases assumed at acquisition based upon estimated cash flow projections that utilize appropriate discount rates and available market information. Refer to the policy section "Intangible Assets and Liabilities" for more information on the Company’s accounting for intangibles. Depreciation is computed using the straight-line method over the shorter of the estimated useful life at acquisition of the capitalized item or 40 years for buildings, five to ten years for building equipment and fixtures, and the lesser of the useful life or the remaining lease term for tenant improvements and leasehold interests. Maintenance and repair expenditures are charged to expense as incurred. For transactions that qualify as business combinations, the Company recognizes the assets acquired and liabilities assumed at fair value, including the value of intangible assets and liabilities, and any excess or deficit of the consideration transferred relative to the fair value of the net assets acquired is recorded as goodwill or a bargain purchase gain, as appropriate. Acquisition costs of business combinations are expensed as incurred. Capital Improvements In leasing space, the Company may provide funding to the lessee through a tenant allowance. Certain improvements are capitalized when they are determined to increase the useful life of the building. During construction of qualifying projects, the Company capitalizes project management fees as permitted to be charged under the lease, if incremental and identifiable. In accounting for tenant allowances, the Company determines whether the allowance represents funding for the construction of leasehold improvements and evaluates the ownership of such improvements. If the Company is considered the owner of the leasehold improvements, the Company capitalizes the amount of the tenant allowance and depreciates it over the shorter of the useful life of the leasehold improvements or the lease term. If the tenant allowance represents a payment for a purpose other than funding leasehold improvements, or in the event the Company is not considered the owner of the improvements for accounting purposes, the allowance is considered to be a lease incentive and is recognized over the lease term as a reduction of rental revenue. Factors considered during this evaluation usually include (i) who holds legal title to the improvements, (ii) evidentiary requirements concerning the spending of the tenant allowance, and (iii) other controlling rights provided by the lease agreement (e.g. unilateral control of the tenant space during the build-out process). Determination of the accounting for a tenant allowance is made on a case-by-case basis, considering the facts and circumstances of the individual tenant lease. Impairments The Company reviews the recoverability of a property’s carrying value when circumstances indicate a possible impairment of the value of a property, such as an adverse change in future expected occupancy or a significant decrease in the market price of an asset. The review of recoverability is based on an estimate of the future undiscounted cash flows, excluding interest charges, expected to result from the property’s use and eventual disposition. These estimates consider factors such as changes in strategy resulting in an increased or decreased holding period, expected future operating income, market and other applicable trends and residual value, as well as the effects of leasing demand, competition and other factors. If management determines impairment exists due to the inability to recover the carrying value of a property, for properties to be held and used, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property and for assets held for sale, an impairment loss is recorded to the extent that the carrying value exceeds the fair value less estimated cost of disposal. These assessments are recorded as an impairment loss in the Condensed Consolidated Statements of Operations in the period the determination is made. The estimated fair value of the asset becomes its new cost basis. For a depreciable long-lived asset to be held and used, the new cost basis will be depreciated or amortized over the remaining useful life of that asset. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Restricted Cash The Company had restricted cash of $19,183 and $12,904 at September 30, 2017 and December 31, 2016 , respectively, which primarily consisted of reserves for certain capital improvements, leasing, interest and real estate tax and insurance payments as required by certain mortgage note obligations. Variable Interest Entities The Company had two and three consolidated VIEs as of September 30, 2017 and December 31, 2016 , respectively. The Company had three and four unconsolidated VIEs as of September 30, 2017 and December 31, 2016 , respectively. The following is a summary of the Company’s involvement with VIEs as of September 30, 2017 : Company carrying value-assets Company carrying value-liabilities Face value of assets held by the VIEs Face value of liabilities issued by the VIEs Consolidated VIEs: Operating Partnership $ 6,541,338 $ 3,295,732 $ 6,541,338 $ 3,295,732 Gramercy Europe Asset Management (European Fund Manager) $ 1,736 $ 96 $ 1,736 $ 1,736 Unconsolidated VIEs: Gramercy Europe Asset Management (European Fund Carry Co.) $ 284 $ — $ 1,192 $ 57 Retained CDO Bonds $ 6,167 $ — $ 103,523 $ 80,629 The following is a summary of the Company’s involvement with VIEs as of December 31, 2016 : Company carrying value-assets Company carrying value-liabilities Face value of assets held by the VIEs Face value of liabilities issued by the VIEs Consolidated VIEs: Operating Partnership $ 5,603,527 $ 2,842,493 $ 5,603,527 $ 2,842,493 Proportion Foods $ 22,836 $ 3,041 $ 22,836 $ 23,514 Gramercy Europe Asset Management (European Fund Manager) $ 1,100 $ 47 $ 1,100 $ 1,742 Unconsolidated VIEs: Gramercy Europe Asset Management (European Fund Carry Co.) $ 8 $ — $ 31 $ — Retained CDO Bonds $ 11,906 $ — $ 391,990 $ 592,414 Consolidated VIEs Operating Partnership The Operating Partnership is a consolidated VIE because the Company is its primary beneficiary due to its majority ownership and ability to exercise control over every aspect of the Operating Partnership’s operations. Gramercy Europe Asset Management (European Fund Manager) In connection with the Company’s December 2014 investment in the Gramercy European Property Fund, the Company acquired equity interests in the entity, hereinafter European Fund Manager, which provides investment and asset management services to the Gramercy European Property Fund. The Company determined that European Fund Manager is a VIE, as the equity holders of that entity do not have controlling financial interests and do not have the obligation to absorb losses. As Gramercy Europe Asset Management, through an investment advisory agreement with the VIE, controls the activities that most significantly affect the economic outcome of European Fund Manager, the Company concluded that it is the entity’s primary beneficiary and has consolidated the VIE. The Company receives net cash inflows from European Fund Manager in the form of management fees, and if the VIE’s cash inflows are not sufficient to cover its obligations, the Company may provide financial support for the VIE. Following the sale of the assets of the Gramercy European Property Fund in July 2017, European Fund Manager commenced liquidation and will be dissolved over the succeeding months. Related to the sale and forthcoming dissolution of European Fund Manager, the Company contributed $471 ( €400 ) to European Fund Manager during the three and nine months ended September 30, 2017. Proportion Foods In December 2015, the Company entered into a non-recourse financing arrangement with Big Proportion Austin LLC, or BIG, for a build-to-suit industrial property in Round Rock, Texas, or Proportion Foods. Concurrently, the Company entered into a forward purchase agreement with BIG, pursuant to which the Company agreed to acquire the property, which is 100.0% leased to Proportion Foods, upon substantial completion of the facility’s development. The Company determined that Proportion Foods was a VIE, as the equity holders of the entity did not have controlling financial interests and were not obligated to absorb losses. The Company controlled the activities that most significantly affected the economic outcome of Proportion Foods through its financing arrangement to fund the property’s development and its forward purchase agreement with BIG. As such, the Company concluded it was the entity’s primary beneficiary and consolidated the VIE. The construction of the facility on the property was completed in March 2017, at which time the Company acquired the property. Following the acquisition, the property was wholly-owned by the Company and was no longer a consolidated VIE. Unconsolidated VIEs Gramercy Europe Asset Management (European Fund Carry Co.) In connection with the Company’s December 2014 investment in the Gramercy European Property Fund, the Company acquired equity interests in the entity, hereinafter European Fund Carry Co., entitled to receive certain preferential distributions, if any, made from time-to-time by the Gramercy European Property Fund. The Company determined that European Fund Carry Co. is a VIE, as the equity holders of that entity do not have controlling financial interests and do not have the obligation to absorb losses in excess of capital committed. Decisions that most significantly affect the economic performance of European Fund Carry Co. are decided by a majority vote of that VIE’s shareholders. As such, the Company does not have a controlling financial interest in the VIE and accounts for it as an equity investment. Following the sale of the assets of the Gramercy European Property Fund in July 2017, European Fund Carry Co. commenced liquidation and will be dissolved over the succeeding months. Investment in Retained CDO Bonds The Company has retained non-investment grade subordinate bonds, preferred shares and ordinary shares of three collateralized debt obligations, or CDOs, together the Retained CDO Bonds. The Company does not control the activities that most significantly impact the Retained CDO Bonds’ economic performance and is not obligated to provide any financial support to them, thus the Retained CDO Bonds have been determined to be unconsolidated VIEs, in which the Company’s interest is recorded at fair value within other assets on the Condensed Consolidated Balance Sheets. The Retained CDO Bonds may provide the potential for the Company to receive continuing cash flows in the future, however, there is no guarantee that the Company will realize any proceeds from the Retained CDO Bonds or what the timing of the proceeds may be. The Company’s maximum exposure to loss is limited to its interest in the Retained CDO Bonds. In April 2017, one of the CDOs, in which the Company’s retained interest has no value, commenced liquidation. The Company will not receive any proceeds from the liquidation. Thus, as of September 30, 2017 , one of the Retained CDO Bonds is no longer considered a VIE of the Company. Tenant and Other Receivables Tenant and other receivables are derived from rental revenue, tenant reimbursements, and management fees. Rental revenue is recorded on a straight-line basis over the initial term of the lease. Since many leases provide for rental increases at specified intervals, straight-line basis accounting requires the Company to record a receivable, and include in revenues, unbilled rent receivables that will only be received if the tenant makes all rent payments required through the expiration of the initial term of the lease. Tenant and other receivables also include receivables related to tenant reimbursements for common area maintenance expenses and certain other recoverable expenses that are recognized as revenue in the period in which the related expenses are incurred. Tenant and other receivables are recorded net of the allowances for doubtful accounts, which as of September 30, 2017 and December 31, 2016 were $691 and $57 , respectively. The Company continually reviews receivables related to rent, tenant reimbursements, and management fees, including incentive fees, and determines collectability by taking into consideration the tenant or asset management clients’ payment history, the financial condition of the tenant or asset management client, business conditions in the industry in which the tenant or asset management client operates and economic conditions in the area in which the property or asset management client is located. In the event that the collectability of a receivable is in doubt, the Company increases the allowance for doubtful accounts or records a direct write-off of the receivable, as appropriate. Management fees, including incentive management fees, are recognized as earned in accordance with the terms of the management agreements. The management agreements may contain provisions for fees related to dispositions, administration of the assets including fees related to accounting, valuation and legal services, and management of capital improvements or projects on the underlying assets. Intangible Assets and Liabilities As discussed above in the policy section “Real Estate Acquisitions” the Company follows the acquisition method of accounting for its asset acquisitions and business combinations and thus allocates the purchase price of acquired properties to tangible and identifiable intangible assets acquired based on their respective fair values. Identifiable intangible assets include amounts allocated to acquired leases for above- and below- market lease rates and the value of in-place leases. Management also considers information obtained about each property as a result of its pre-acquisition due diligence. Above-market and below-market lease values for properties acquired are recorded based on the present value of the difference between the contractual amount to be paid pursuant to each in-place lease and management’s estimate of the fair market lease rate for each such in-place lease, measured over a period equal to the remaining non-cancelable term of the lease. The present value calculation utilizes a discount rate that reflects the risks associated with the leases acquired. The above-market and below-market lease values are amortized as a reduction of and increase to rental revenue, respectively, over the remaining non-cancelable terms of the respective leases. If a tenant terminates its lease prior to its contractual expiration and no future rental payments will be received, any unamortized balance of the market lease intangibles will be written off to rental revenue. The aggregate value of in-place leases represents the costs of leasing costs, other tenant related costs, and lost revenue that the Company did not have to incur by acquiring a property that is already occupied. Factors considered by management in its analysis of the in-place lease intangibles include an estimate of carrying costs during the expected lease-up period for each property taking into account current market conditions and costs to execute similar leases, including leasing commissions and other related expenses. In estimating carrying costs, management includes real estate taxes, insurance and other operating expenses and estimates of lost rentals at market rates during the anticipated lease-up period. The value of in-place leases is amortized to depreciation and amortization expense over the remaining non-cancelable term of the respective leases, but never over a term that exceeds the remaining depreciable life of the building. If a tenant terminates its lease prior to its contractual expiration and no future rental payments will be received, any unamortized balance of the in-place lease intangible will be written off to depreciation and amortization expense. Above-market and below-market ground rent intangibles are recorded for properties acquired in which the Company is the lessee pursuant to a ground lease assumed at acquisition. The above-market and below-market ground rent intangibles are valued similarly to above-market and below-market leases, except that, because the Company is the lessee as opposed to the lessor, the above-market and below-market ground lease values are amortized as a reduction of and increase to rent expense, respectively, over the remaining non-cancelable terms of the respective leases. Intangible assets and liabilities consist of the following: September 30, 2017 December 31, 2016 Intangible assets: In-place leases, net of accumulated amortization of $178,430 and $117,717 $ 571,839 $ 553,924 Above-market leases, net of accumulated amortization of $22,969 and $15,719 51,421 59,647 Below-market ground rent, net of accumulated amortization of $369 and $274 5,014 5,109 Amounts related to assets held for sale, net of accumulated amortization of $758 and $0 (2,503 ) — Total intangible assets $ 625,771 $ 618,680 Intangible liabilities: Below-market leases, net of accumulated amortization of $27,853 and $26,168 $ 171,251 $ 223,110 Above-market ground rent, net of accumulated amortization of $409 and $248 6,893 7,073 Amounts related to liabilities of assets held for sale, net of accumulated amortization of $698 and $0 (4,567 ) — Total intangible liabilities $ 173,577 $ 230,183 The following table provides the weighted-average amortization period as of September 30, 2017 for intangible assets and liabilities and the projected amortization expense for the next five years. Weighted-Average Amortization Period (years) October 1 to December 31, 2017 2018 2019 2020 2021 In-place leases 9.3 $ 26,269 $ 100,181 $ 85,178 $ 71,067 $ 59,907 Total to be included in depreciation and amortization expense $ 26,269 $ 100,181 $ 85,178 $ 71,067 $ 59,907 Above-market lease assets 7.1 $ 2,688 $ 10,424 $ 9,425 $ 7,493 $ 6,196 Below-market lease liabilities 17.7 (3,166 ) (12,590 ) (12,240 ) (11,763 ) (10,641 ) Total to be included in rental revenue $ (478 ) $ (2,166 ) $ (2,815 ) $ (4,270 ) $ (4,445 ) Below-market ground rent 40.6 $ 32 $ 127 $ 127 $ 127 $ 127 Above-market ground rent 32.5 (53 ) (214 ) (214 ) (214 ) (214 ) Total to be included in property operating expense $ (21 ) $ (87 ) $ (87 ) $ (87 ) $ (87 ) The Company recorded $25,525 and $29,670 of amortization of in-place lease intangible assets as part of depreciation and amortization for the three months ended September 30, 2017 and 2016 , respectively. The Company recorded $73,864 and $86,845 of amortization of in-place lease intangible assets as part of depreciation and amortization for the nine months ended September 30, 2017 and 2016 , respectively. The Company recorded $(872) and $4,578 of amortization of market lease intangible assets and liabilities as an increase (decrease) to rental revenue for the three months ended September 30, 2017 and 2016 , respectively. The Company recorded $4,505 and $10,388 of amortization of market lease intangible assets and liabilities as an increase to rental revenue for the nine months ended September 30, 2017 and 2016 , respectively. The Company recorded $(23) and $8 of amortization of ground rent intangible assets and liabilities as part of property operating expense for the three months ended September 30, 2017 and 2016 , respectively. The Company recorded $(66) and $25 of amortization of ground rent intangible assets and liabilities as part of property operating expense for the nine months ended September 30, 2017 and 2016 , respectively. Revenue Recognition Real Estate Investments Rental revenue from leases on real estate investments is recognized on a straight-line basis over the term of the lease, regardless of when payments are contractually due. The excess of rental revenue recognized over the amounts contractually due according to the underlying leases are included in other liabilities on the Condensed Consolidated Balance Sheets. For leases on properties that are under construction at the time of acquisition, the Company begins recognition of rental revenue upon completion of construction of the leased asset and delivery of the leased asset to the tenant. The Company’s lease agreements with tenants also generally contain provisions that require tenants to reimburse the Company for real estate taxes, insurance costs, common area maintenance costs, and other property-related expenses. Under lease arrangements in which the Company is the primary obligor for these expenses, such amounts are recognized as both revenues and operating expenses for the Company. Under lease arrangements in which the tenant pays these expenses directly, such amounts are not included in revenues or expenses. These reimbursement amounts are recognized in the period in which the related expenses are incurred. The Company recognizes sales of real estate properties only upon closing. Payments received from purchasers prior to closing are recorded as deposits. Profit on real estate sold is recognized using the full accrual method upon closing when the collectability of the sale price is reasonably assured and the Company is not obligated to perform significant activities after the sale. Profit may be deferred in whole or part until the sale meets the requirements of profit recognition on sale of real estate. Third-Party Management Fees The Company’s asset and property management agreements may contain provisions for fees related to administration of the assets including fees related to accounting, valuation and legal services, and management of capital improvements or projects on the underlying assets. The Company recognizes revenue for fees pursuant to its management agreements in the period in which they are earned. Deferred revenue from management fees received prior to the date earned is included in other liabilities on the Condensed Consolidated Balance Sheets. Certain of the Company’s asset management contracts and agreements with its unconsolidated equity investments include provisions that allow it to earn additional fees, generally described as incentive fees or promoted interests, based on the achievement of a targeted valuation or the achievement of a certain internal rate of return on the managed assets held by third parties or the equity investment. The Company recognizes incentive fees on its asset management contracts based upon the amount that would be due pursuant to the contract, if the contract were terminated at the reporting date. If the incentive fee is a fixed amount, only a proportionate share of revenue is recognized at the reporting date, with the remaining fees recognized on a straight-line basis over the measurement period. The Company recognizes promoted interest in the period in which it is determined to be appropriately earned pursuant to the terms of the specific agreement. The values of incentive management fees and promoted interest fees are periodically evaluated by management. For the three months ended September 30, 2017 , the Company did no t recognize any incentive fee revenue and for the nine months ended September 30, 2017 , the Company recognized incentive fees of $1,449 . For the three and nine months ended September 30, 2016 , the Company recognized incentive fees of $2,931 and $18,121 , respectively. Other Income Other income primarily consists of miscellaneous property related income, lease termination fees, income accretion on the Company’s Retained CDO Bonds, realized foreign currency exchange gains (losses), and interest income. Foreign Currency Gramercy Europe Asset Management performs asset and property management services in Europe. The Company has unconsolidated equity investments in Europe and Asia and had two wholly-owned properties in Canada and one wholly-owned property in the United Kingdom until their dispositions in March 2017 and December 2016, respectively. The Company also has had borrowings outstanding in euros and British pounds sterling under the multicurrency portion of its revolving credit facility during 2017. Refer to Note 5 for more information on the Company’s foreign unconsolidated equity investments. Foreign Currency Translation During the periods presented, the Company has had interests in Europe and Canada for which the functional currencies are the euro, the British pound sterling, and the Canadian dollar, respectively. The Company performs the translation from these foreign currencies to the U.S. dollar for assets and liabilities using the exchange rates in effect at the balance sheet date and for revenue and expense accounts using a weighted average exchange rate during the period. The Company reports the gains and losses resulting from such translation as a component of other comprehensive income. For the three and nine months ended September 30, 2017 , the Company recorded net translation gains of $685 and $2,502 , respectively. For the three and nine months ended September 30, 2016 , the Company recorded net translation losses of $1,120 and $3,687 , respectively. Translation gains and losses are reclassified to other income within earnings when the Company has substantially exited from the foreign currency denominated asset or liability. Foreign Currency Transactions A transaction gain or loss realized upon settlement of a foreign currency transaction will be included in earnings for the period in which the transaction is settled. Foreign currency intercompany transactions that are scheduled for settlement are included in the determination of net income. Intercompany foreign cur

Dispositions, Assets Held for S

Dispositions, Assets Held for Sale, and Discontinued Operations	9 Months Ended
	Sep. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Dispositions, Assets Held for Sale, and Discontinued Operations	Dispositions, Assets Held for Sale, and Discontinued Operations Real Estate Dispositions and Impairments During the three and nine months ended September 30, 2017 , the Company sold eight and 25 properties, respectively, as well as two offices that are part of another asset during the nine months ended September 30, 2017 . The property sales in 2017 comprised an aggregate 2,358,928 square feet and generated gross proceeds of $256,828 . During the three and nine months ended September 30, 2017 , the Company recognized a net gain on disposals of $4,879 and $24,258 , respectively, related to eight and 23 properties sold during the periods, respectively, as well as two offices sold from another asset during the nine months ended September 30, 2017 . During the three and nine months ended September 30, 2017 , the Company recognized impairments of $3,064 and $21,415 , respectively, of which $7,973 is related to four properties held as of September 30, 2017 that were determined to have non-recoverable declines in value during the period, and the remainder is related to properties sold during the periods. Refer to Note 9 for more information on how the Company determined the non-recurring fair value of these properties. The Company sold 10 and 20 properties during the three and nine months ended September 30, 2016 , respectively. The Company recognized an impairment on real estate investments of $1,053 during the three and nine months ended September 30, 2016 related to the properties sold during the period. The Company recognized $2,336 in gains on disposals during the three and nine months ended September 30, 2016 . Of the properties sold during the nine months ended September 30, 2017 , 10 of the sales were structured as like-kind exchanges within the meaning of Section 1031 of the Internal Revenue Code, or IRC. As a result of the sales, the Company deposited $176,895 of the total sale proceeds into an IRC Section 1031 exchange escrow account with a qualified intermediary. The Company then used $176,894 of these funds as consideration for 13 property acquisitions during the nine months ended September 30, 2017 . Assets Held for Sale The Company separately classifies properties held for sale in the Condensed Consolidated Financial Statements. The Company had three properties and one land parcel within another asset classified as held for sale as of September 30, 2017 with total net asset value of $12,378 and no assets classified as held for sale as of December 31, 2016 . In the normal course of business, the Company identifies non-strategic assets for sale. Real estate investments to be disposed of are reported at the lower of carrying amount or estimated fair value, less costs to sell. Once an asset is classified as held for sale, depreciation and amortization expense is no longer recorded. The following table summarizes the assets held for sale and liabilities related to the assets held for sale as of September 30, 2017 : Assets held for sale September 30, 2017 Real estate investments $ 14,507 Acquired lease assets, net 2,503 Other assets 282 Total assets $ 17,292 Liabilities related to assets held for sale Below-market lease liabilities, net 4,567 Other liabilities 347 Total liabilities $ 4,914 Net assets held for sale $ 12,378 Discontinued Operations The Company’s discontinued operations for the three and nine months ended September 30, 2017 and 2016 were related to the assets that were assumed in the Merger and simultaneously designated as held for sale. The following operating results for the three and nine months ended September 30, 2017 and 2016 are included in discontinued operations for all periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Revenues $ 6 $ 262 $ 3 $ 6,259 Operating expenses — (58 ) 6 (2,294 ) General and administrative expense (30 ) (3 ) (85 ) (41 ) Interest expense — 148 — (807 ) Depreciation and amortization — (2 ) — (2 ) Gain on extinguishment of debt — — — 1,930 Income (loss) from discontinued operations $ (24 ) $ 347 $ (76 ) $ 5,045 Discontinued operations have not been segregated in the Condensed Consolidated Statements of Cash Flows. The table below presents additional relevant information pertaining to results of discontinued operations for the nine months ended September 30, 2017 and 2016 , including depreciation, amortization, capital expenditures, and significant operating and investing non-cash items: Nine Months Ended September 30, 2017 2016 Amortization expense $ — $ 2 Significant operating non-cash items — (9,647 ) Total $ — $ (9,645 )

Real Estate Investments

Real Estate Investments	9 Months Ended
	Sep. 30, 2017
Real Estate [Abstract]
Real Estate Investments	Real Estate Investments Property Acquisitions During the nine months ended September 30, 2017 , the Company acquired 74 properties comprising 18,361,835 square feet for an aggregate contract purchase price of approximately $1,321,886 , including the acquisition of a consolidated VIE for $29,605 , a vacant property for $2,400 , two land parcels for $6,840 , and one build-to-suit property upon completion for $63,244 . Additionally, during the nine months ended September 30, 2017 , the Company acquired two land parcels for an aggregate purchase price of $2,800 , on which it has committed to construct an industrial facility for an estimated $25,805 with projected completion in October 2017 and an industrial facility for an estimated $23,272 with projected completion in March 2018. Total value of the properties acquired during the nine months ended September 30, 2017 was comprised of $1,226,190 of real estate assets, $125,882 of intangible assets, and $15,834 of intangible liabilities, including acquisition costs capitalized for the asset acquisitions. Property Purchase Price Allocations As described in Note 2 , during the first quarter of 2017 the Company adopted ASU 2017-01, Amendments to Business Combinations, which amends the definition of a business and provides a revised framework for the determination of whether an integrated set of assets and activities meets the definition of a business. The Company evaluated its real estate acquisitions during the nine months ended September 30, 2017 under the new framework and, accordingly, accounted for the transactions as asset acquisitions. Prior to adoption of ASU 2017-01 in 2017, the majority of the Company’s acquisitions were accounted for as business combinations. Of the acquisitions prior to 2017, there were 21 properties acquired in 2016 that were accounted for as business combinations which had preliminary purchase price allocations recorded as of December 31, 2016 . The Company finalized the purchase price allocations of these 21 properties during the first quarter of 2017. The aggregate changes recorded from the preliminary purchase price allocations to the finalized purchase price allocations, are shown in the table below and are reflected in earnings for the nine months ended September 30, 2017 : Preliminary Allocations recorded Finalized Allocations recorded Real Estate Assets Intangible Assets Intangible Liabilities Real Estate Assets Intangible Assets Intangible Liabilities Decrease to Rental Revenue Increase to Depreciation and Amortization Expense $ 513,424 $ 61,178 $ 11,093 $ 513,087 $ 60,627 $ 10,205 $ 27 $ 16

Unconsolidated Equity Investmen

Unconsolidated Equity Investments	9 Months Ended
	Sep. 30, 2017
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Unconsolidated Equity Investments	Unconsolidated Equity Investments The Company accounts for substantially all of its unconsolidated equity investments under the equity method of accounting because it exercises significant influence, but does not unilaterally control the entities, and is not considered to be the primary beneficiary. In unconsolidated equity investments, the rights of the other investors are protective and participating. Unless the Company is determined to be the primary beneficiary, these rights preclude it from consolidating the investments. The investments are recorded initially at cost as unconsolidated equity investments, as applicable, and subsequently are adjusted for equity interest in net income and contributions and distributions. The amount of the investments on the Condensed Consolidated Balance Sheets is evaluated for impairment at each reporting period. None of the unconsolidated equity investment debt is recourse to the Company. Transactions with unconsolidated equity method entities are eliminated to the extent of the Company’s ownership in each such entity. Accordingly, the Company’s share of net income of these equity method entities is included in consolidated net income. As a result of the Merger in 2015, the Company acquired an interest in four unconsolidated entities, the Goodman Europe JV, the Goodman UK JV, the Duke JV, and CBRE Strategic Partners Asia, which are described below within this note. The Company’s equity investment in the entities was fair valued on the Merger closing date, and the difference between the historical carrying value of the net assets and the fair value was recorded as a basis difference, which is amortized to equity in net income from unconsolidated equity investments over the remaining weighted average useful life of the underlying assets of each entity. As of September 30, 2017 and December 31, 2016 , the Company owned properties through unconsolidated equity investments and had investment interests in these unconsolidated entities as follows: As of September 30, 2017 As of December 31, 2016 Investment Ownership % Voting Interest % Partner Investment in Unconsolidated Equity Investment 1 No. of Properties Investment in Unconsolidated Equity Investment 1 No. of Properties Gramercy European Property Fund 2 14.2 % 14.2 % Various $ 1,109 — $ 50,367 26 Goodman Europe JV 3 — % — % Gramercy European Property Fund — — 3,491 8 Strategic Office Partners 25.0 % 25.0 % TPG Real Estate 35,760 11 15,872 6 Goodman UK JV 80.0 % 50.0 % Goodman Group 30,884 1 25,309 2 CBRE Strategic Partners Asia 5.07 % 5.07 % Various 2,772 1 4,145 2 Philips JV 25.0 % 25.0 % Various — 1 — 1 Morristown JV 50.0 % 50.0 % 21 South Street 2,638 1 2,623 1 Total $ 73,163 15 $ 101,807 46 1. The amounts presented include a basis difference of $1,930 , net of accumulated amortization, for the Goodman UK JV as of September 30, 2017 . The amounts presented include basis differences of $2,286 and $3,941 , net of accumulated amortization, for the Goodman Europe JV and Goodman UK JV, respectively, as of December 31, 2016 . 2. The Gramercy European Property Fund sold 100.0% of its assets to a third party in July 2017. Pursuant to the sale agreement, as of September 30, 2017 , $1,109 of the sale proceeds are being held in escrow, thus this remaining distribution held in escrow represents the total value of the Company’s investment in the entity following the transaction. The amounts presented include European Fund Carry Co., which has a carrying value of $284 and $8 for the Company’s 25.0% interest as of September 30, 2017 and December 31, 2016 , respectively. 3. In the table above the Company’s 94.9% indirect interest in the Goodman Europe JV held through its 14.2% interest in the Gramercy European Property Fund is included in the amount shown for the Gramercy European Property Fund and the Company’s 5.1% direct interest in the Goodman Europe JV is presented separately as the amount shown for the Goodman Europe JV. In July 2017, the Company sold its 5.1% direct interest in the Goodman Europe JV and the assets of the Goodman Europe JV were sold to a third party as part of the aforementioned sale of the assets of Gramercy European Property Fund. The following is a summary of the Company’s unconsolidated equity investments for the nine months ended September 30, 2017 : Unconsolidated Equity Investments Balance at January 1, 2017 $ 101,807 Contributions to unconsolidated equity investments 20,775 Equity in net income of unconsolidated equity investments, including adjustments for basis differences 48,884 Other comprehensive income of unconsolidated equity investments 7,286 Distributions from unconsolidated equity investments (96,434 ) Reclassification of unrealized gain on non-derivative net investment hedge into earnings 1,851 Sale of unconsolidated equity investment interests (9,644 ) Reclassification of accumulated foreign currency translation adjustments due to disposal (1,362 ) Balance at September 30, 2017 $ 73,163 Gramercy European Property Fund In December 2014, the Company, along with several equity investment partners, formed the Gramercy European Property Fund, a private real estate investment fund that targets single-tenant industrial, office and specialty retail assets throughout Europe. Since inception, the equity investors, including the Company, collectively funded $395,213 ( €352,500 ) in equity capital to the Gramercy European Property Fund, of which the Company's cumulative contributions were $55,892 ( €50,000 ). In July 2017, the Gramercy European Property Fund sold 100.0% of its assets to a third party, including 30 properties that it 100.0% owned and eight additional properties that it had a 94.9% interest in through its investment in the Goodman Europe JV. Concurrently, the Company sold its 5.1% direct interest in the Goodman Europe JV to the same entity that acquired the Gramercy European Property Fund’s assets. The transactions resulted in net distributions to the Company of approximately $101,930 ( €89,366 ), inclusive of a promoted interest distribution of approximately $8,515 ( €7,448 ). As a result of the transactions, during the three months ended September 30, 2017 the Company recorded net gain on disposal of $27,613 and $6,458 related to the Gramercy European Property Fund and the Goodman Europe JV, respectively, including $(634) and $145 , respectively, related to the write-off of accumulated other comprehensive income, as well as approximately $8,515 of fee income related to the promoted interest from the European Fund Carry Co. All of these amounts are recorded within equity in net income of unconsolidated equity investments on the Company’s Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2017 . Following the transactions, the Gramercy European Property Fund had no properties, the value of the Company’s investment in the Gramercy European Property Fund was $1,109 ( €939 ), which primarily represents the amount of funds being held in escrow pending release in the fourth quarter of 2017, and the Company had no remaining interest in the Goodman Europe JV. Subsequent to the closing of the transactions, European Fund Carry Co. and European Fund Manager commenced liquidation and will be dissolved over the succeeding months. Refer to the Management’s Discussion and Analysis for further information on the transaction. During the three and nine months ended September 30, 2017 , the Company received no distributions and distributions of $689 , respectively, from the Goodman Europe JV, and no distributions from the Gramercy European Property Fund, excluding the distributions related to the sale transactions described above. Strategic Office Partners In August 2016, the Company partnered with TPG Real Estate, or TPG, to form Strategic Office Partners, an unconsolidated equity investment created for the purpose of acquiring, owning, operating, leasing and selling single-tenant office properties located in high-growth metropolitan areas in the United States. In September 2016, the Company contributed six properties to Strategic Office Partners and during the nine months ended September 30, 2017 , Strategic Office Partners acquired six properties and sold one property. The Company provides asset and property management, accounting, construction, and leasing services to Strategic Office Partners, for which it earns management fees and is entitled to a promoted interest. TPG and the Company have committed to fund an aggregate $400,000 to Strategic Office Partners, including $100,000 from the Company. During the three and nine months ended September 30, 2017 , the Company contributed $13,375 and $20,775 , respectively, to Strategic Office Partners and as of September 30, 2017 , the Company's remaining commitment is $63,198 . During the three and nine months ended September 30, 2017 , the Company received distributions of $2,710 from the Strategic Office Partners. Goodman UK JV The Goodman UK JV invests in one industrial property in the United Kingdom. During the three and nine months ended September 30, 2017 , the Company received no distributions from the Goodman UK JV. Duke JV The Duke JV invested in industrial and office properties located throughout the United States. In June 2016, the Company and Duke entered into a Dissolution and Liquidation Agreement, pursuant to which the Duke JV distributed seven of its properties to the Company and one of its properties to Duke on June 30, 2016, then was dissolved in July 2016 following the disposition of its remaining property and final distributions of cash to its members. CBRE Strategic Partners Asia CBRE Strategic Partners Asia is a real estate investment fund with investments in China. CBRE Strategic Partners Asia has an eight -year term, which began on January 31, 2008 and may be extended for up to two one -year periods with the approval of two-thirds of the limited partners. In March 2016, the limited partners approved a one-year extension. CBRE Strategic Partners Asia's commitment period has ended, however, it may call capital to fund operations, obligations and liabilities. In February 2017, the fund commenced liquidation and will wind up over the succeeding 24 months. During the three and nine months ended September 30, 2017 , CBRE Strategic Partners Asia sold one of its properties and related to this sale, the Company received distributions of $812 from CBRE Strategic Partners Asia. Philips JV The Company has a 25.0% interest in 200 Franklin Square Drive, a 199,900 square foot building located in Somerset, New Jersey which is 100.0% net leased to Philips Holdings, USA Inc., a wholly-owned subsidiary of Royal Philips Electronics, through December 2021, or the Philips JV. During the three and nine months ended September 30, 2017 , the Company received no distributions and recognized no revenue from the Philips JV. Morristown JV In October 2015, the Company contributed 50.0% of its interest in an office property located in Morristown, New Jersey to a joint venture the Company formed with 21 South Street, a subsidiary of Hampshire Partners Fund VIII LP, or the Morristown JV. Concurrent with the contribution, the Company sold the remaining 50.0% equity interest of the property to 21 South Street. The following are the balance sheets for the Company’s unconsolidated equity investments at September 30, 2017 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia Other 2 Assets: Real estate assets, net 3 $ — $ — $ — $ 259,949 $ 18,678 $ 78,202 $ 48,784 Other assets — 12,084 12,084 57,319 20,314 11,214 4,217 Total assets $ — $ 12,084 $ 12,084 $ 317,268 $ 38,992 $ 89,416 $ 53,001 Liabilities and members’ equity: Mortgage notes payable $ — $ — $ — $ 159,140 $ — $ — $ 38,973 Other liabilities — 5,126 5,126 13,008 194 14,677 3,407 Total liabilities — 5,126 5,126 172,148 194 14,677 42,380 Company’s equity — 825 825 35,760 30,884 2,772 2,922 Other members’ equity — 6,133 6,133 109,360 7,914 71,967 7,699 Liabilities and members’ equity $ — $ 12,084 $ 12,084 $ 317,268 $ 38,992 $ 89,416 $ 53,001 1. In July 2017, the Gramercy European Property Fund sold 100.0% of its assets, including its 94.9% interest in the Goodman Europe JV. The remaining net assets as of September 30, 2017 primarily represent a portion of the sale proceeds being held in escrow, pursuant to the sale agreement. 2. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The amounts that pertain to European Fund Carry Co. include assets of $1,192 , liabilities of $57 , the Company’s 25.0% share of equity totaling $284 , and other members’ equity of $851 . 3. Includes basis adjustments that were recorded by the Company to adjust the unconsolidated equity investments to fair value upon closing of the Merger. The following are the balance sheets for the Company’s unconsolidated equity investments at December 31, 2016 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund 2 Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia Other 3 Assets: Real estate assets, net 4 $ 285,087 $ 347,069 $ 632,156 $ 149,484 $ 25,128 $ 87,852 $ 49,580 Other assets 86,273 63,523 149,796 42,323 6,650 12,247 3,020 Total assets $ 371,360 $ 410,592 $ 781,952 $ 191,807 $ 31,778 $ 100,099 $ 52,600 Liabilities and members' equity: Mortgage notes payable $ 174,269 $ 215,980 $ 390,249 $ 121,894 $ — $ — $ 39,730 Other liabilities 7,778 19,940 27,718 4,347 934 14,383 3,259 Total liabilities 182,047 235,920 417,967 126,241 934 14,383 42,989 Company's equity 12,734 41,116 53,850 15,872 25,309 4,145 2,631 Other members' equity 176,579 133,556 310,135 49,694 5,535 81,571 6,980 Liabilities and members' equity $ 371,360 $ 410,592 $ 781,952 $ 191,807 $ 31,778 $ 100,099 $ 52,600 1. As of December 31, 2016 , the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. In the table above, the Company’s equity interest in the Goodman Europe JV includes both its direct 5.1% interest as well as its indirect interest that was held through its 14.2% interest in the Gramercy European Property Fund, and the Company’s equity interest in the Gramercy European Property Fund represents its interest in all of the properties owned by the Gramercy European Property Fund except for the properties in the Goodman Europe JV. 2. Excludes the Gramercy European Property Fund’s 94.9% interest in the Goodman Europe JV. 3. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. 4. Includes basis adjustments that were recorded by the Company to adjust the unconsolidated equity investments to fair value upon closing of the Merger. Certain real estate assets in the Company’s unconsolidated equity investments are subject to mortgage notes. The following is a summary of the secured financing arrangements within the Company’s unconsolidated equity investments as of September 30, 2017 : Outstanding Balance 2 Property Unconsolidated Equity Investment Economic Ownership Interest Rate 1 Maturity Date September 30, 2017 December 31, 2016 Strategic Office Partners portfolio 3 Strategic Office Partners 25.0% 4.23% 10/7/2019 $ 162,080 $ 125,000 Durrholz, Germany Gramercy European Property Fund 14.2% 1.52% 3/31/2020 — 12,289 Venray, Germany Gramercy European Property Fund 14.2% 3.32% 12/2/2020 — 13,015 Lille, France Gramercy European Property Fund 14.2% 3.13% 12/17/2020 — 27,081 Carlisle, United Kingdom Gramercy European Property Fund 14.2% 3.32% 2/19/2021 — 10,443 Oud Beijerland, Netherlands Gramercy European Property Fund 14.2% 2.09% 12/30/2022 — 8,077 Zaandam, Netherlands Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 11,647 Kerkrade, Netherlands Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 9,622 Friedrichspark, Germany Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 8,694 Fredersdorf, Germany Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 11,247 Breda, Netherlands Gramercy European Property Fund 14.2% 1.90% 12/30/2022 — 9,948 Juechen, Germany Gramercy European Property Fund 14.2% 1.89% 12/30/2022 — 18,852 Piaseczno, Poland Gramercy European Property Fund 14.2% 1.98% 12/30/2022 — 8,141 Strykow, Poland Gramercy European Property Fund 14.2% 1.98% 12/30/2022 — 19,167 Uden, Netherlands Gramercy European Property Fund 14.2% 1.98% 12/30/2022 — 8,913 Rotterdam, Netherlands Gramercy European Property Fund 14.2% 1.89% 12/30/2022 — 7,633 Frechen, Germany Gramercy European Property Fund 14.2% 1.49% 12/30/2022 — 6,043 Meerane, Germany Gramercy European Property Fund 14.2% 1.35% 12/30/2022 — 10,138 Amsterdam, Netherlands Gramercy European Property Fund 14.2% 1.59% 12/30/2022 — 3,093 Tiel, Netherlands Gramercy European Property Fund 14.2% 1.59% 12/30/2022 — 9,174 Netherlands portfolio 4 Gramercy European Property Fund 14.2% 3.02% 6/28/2023 — 13,409 Kutno, Poland Gramercy European Property Fund 14.2% 1.91% 7/21/2023 — 5,890 European Facility 1 5 Goodman Europe JV 18.6% 0.90% 11/16/2023 — 31,551 European Facility 2 5 Goodman Europe JV 18.6% 1.75% 11/16/2023 — 106,917 Worksop, United Kingdom Gramercy European Property Fund 14.2% 3.94% 10/20/2026 — 10,551 Somerset, NJ Philips JV 25.0% 6.90% 9/11/2035 38,973 39,730 Total mortgage notes payable $ 201,053 $ 546,265 Net deferred financing costs and net debt premium (discount) (2,940 ) 5,608 Total mortgage notes payable, net $ 198,113 $ 551,873 1. Represents the current effective rate as of September 30, 2017 , including the swapped interest rate for mortgage notes that have interest rate swaps. The current interest rate is not adjusted to include the amortization of fair market value premiums or discounts. 2. Mortgage notes are presented at 100.0% of the amount held by the unconsolidated equity investment. 3. There are nine properties under this mortgage note. 4. There are five properties under this mortgage note. 5. There were eight properties under this mortgage facility. In addition, this represents the Company’s economic ownership in the Goodman Europe JV, which included both its 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. The following are the statements of operations for the Company’s unconsolidated equity investments for the three months ended September 30, 2017 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia 2 Other 3 Revenues $ 303 $ 593 $ 896 $ 8,451 $ 25 $ (7,766 ) $ 36,224 Operating expenses 33 (1,288 ) (1,255 ) 2,828 82 295 170 Interest expense 29 152 181 2,432 — — 690 Depreciation and amortization 120 237 357 3,969 204 — 333 Total expenses 182 (899 ) (717 ) 9,229 286 295 1,193 Net income (loss) from operations 121 1,492 1,613 (778 ) (261 ) (8,061 ) 35,031 Loss on derivatives — (22 ) (22 ) (144 ) — — — Loss on extinguishment of debt — — — (937 ) — — — Net gain on disposals — 230,392 230,392 9,923 7,871 — — Provision for taxes (38 ) (68 ) (106 ) — 30 — — Net income (loss) $ 83 $ 231,794 $ 231,877 $ 8,064 $ 7,640 $ (8,061 ) $ 35,031 Company's share in net income (loss) $ 4 $ 32,927 $ 32,931 $ 2,125 $ 6,112 $ (411 ) $ 8,777 Adjustments for REIT basis — — — — (2,159 ) — — Gain (loss) from disposal of Company's interest 6,458 (5,103 ) 1,355 — — — — Company's equity in net income (loss) within continuing operations $ 6,462 $ 27,824 $ 34,286 $ 2,125 $ 3,953 $ (411 ) $ 8,777 1. Prior to the sale of the assets of the Gramercy European Property Fund and the Company’s sale of its interest in the Goodman Europe JV to a third party in July 2017, the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the three months ended September 30, 2017 , the Company’s equity in net income (loss) of the entities is based on these ownership interest percentages. 2. The Company received a distribution of $812 related to the sale of a property in September by CBRE Strategic Partners Asia, however, due to the 3-month reporting lag, the Company’s financial results reflect information through June 30, 2017, which includes the sold asset. 3. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The amounts that pertain to European Fund Carry Co. include revenues of $35,127 , expenses of $62 , and the Company’s 25.0% share in net income of $8,766 . The following are statements of operations for the Company’s unconsolidated equity investments for the nine months ended September 30, 2017 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia 2 Other 3 Revenues $ 10,581 $ 22,190 $ 32,771 $ 21,151 $ 613 $ (9,981 ) $ 38,432 Operating expenses 1,900 4,465 6,365 6,618 609 996 444 Interest expense 1,315 3,424 4,739 5,997 — — 2,031 Depreciation and amortization 4,165 10,032 14,197 9,324 840 — 999 Total expenses 7,380 17,921 25,301 21,939 1,449 996 3,474 Net income (loss) from operations 3,201 4,269 7,470 (788 ) (836 ) (10,977 ) 34,958 Gain (loss) on derivatives — 2,248 2,248 (906 ) — — — Loss on extinguishment of debt — — — (937 ) — — — Net gain on disposals — 230,392 230,392 9,923 7,871 — — Provision for taxes (70 ) (346 ) (416 ) — 2 — — Net income (loss) $ 3,131 $ 236,563 $ 239,694 $ 7,292 $ 7,037 $ (10,977 ) $ 34,958 Company’s share in net income (loss) $ 159 $ 33,812 $ 33,971 $ 2,074 $ 5,629 $ (561 ) $ 8,777 Adjustments for REIT basis (73 ) — (73 ) — (2,288 ) — — Gain (loss) from disposal of Company's interest 6,458 (5,103 ) 1,355 — — — — Company’s equity in net income (loss) within continuing operations $ 6,544 $ 28,709 $ 35,253 $ 2,074 $ 3,341 $ (561 ) $ 8,777 1. Prior to the sale of the assets of the Gramercy European Property Fund and the Company’s sale of its interest in the Goodman Europe JV to a third party in July 2017, the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the nine months ended September 30, 2017 , the Company’s equity in net income (loss) of the entities is based on these ownership interest percentages. 2. The Company received a distribution of $812 related to the sale of a property in September by CBRE Strategic Partners Asia, however, due to the 3-month reporting lag, the Company’s financial results reflect information through June 30, 2017, which includes the sold asset. 3. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The amounts that pertain to European Fund Carry Co. include revenues of $35,127 , expenses of $77 , and the Company’s 25.0% share in net income of $8,763 . The following are the statements of operations for the Company’s unconsolidated equity investments for the three months ended September 30, 2016 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV Duke JV CBRE Strategic Partners Asia Other 2 Revenues $ 6,195 $ 7,329 $ 13,524 $ 1,291 $ 557 $ 417 $ (11,557 ) $ 1,080 Operating expenses 676 1,619 2,295 280 225 191 341 129 Acquisition expenses — 2,141 2,141 664 — — — — Interest expense 653 1,138 1,791 410 — — — 698 Depreciation and amortization 3,276 2,800 6,076 898 339 — — 333 Total expenses 4,605 7,698 12,303 2,252 564 191 341 1,160 Net income (loss) from operations 1,590 (369 ) 1,221 (961 ) (7 ) 226 (11,898 ) (80 ) Loss on derivatives — (1,124 ) (1,124 ) (129 ) — — — — Net gain on disposals — — — — — 28,170 — — Provision for taxes — (284 ) (284 ) — — — — — Net income (loss) $ 1,590 $ (1,777 ) $ (187 ) $ (1,090 ) $ (7 ) $ 28,396 $ (11,898 ) $ (80 ) Company’s share in net income (loss) $ 322 $ (252 ) $ 70 $ (273 ) $ (6 ) $ 20,749 $ (605 ) $ (4 ) Adjustments for REIT basis 11 — 11 — (183 ) (20,897 ) — — Company’s equity in net income (loss) within continuing operations $ 333 $ (252 ) $ 81 $ (273 ) $ (189 ) $ (148 ) $ (605 ) $ (4 ) 1. As of and for the three months ended September 30, 2016 , the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the three months ended September 30, 2016 , the Company’s equity in net income (loss) from the entities is based on these ownership interest percentages during the period. 2. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The following are the statements of operations for the Company’s unconsolidated equity investments for the nine months ended September 30, 2016 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV Duke JV CBRE Strategic Partners Asia Other 2 Revenues $ 18,389 $ 18,270 $ 36,659 $ 1,291 $ 5,477 $ 19,812 $ (11,315 ) $ 3,245 Operating expenses 2,372 3,188 5,560 280 698 5,309 1,208 342 Acquisition expenses 4,960 4,678 9,638 664 — — — 27 Interest expense 2,519 3,032 5,551 410 — 602 — 2,131 Depreciation and amortization 7,907 7,632 15,539 898 1,461 7,154 — 998 Total expenses 17,758 18,530 36,288 2,252 2,159 13,065 1,208 3,498 Net income (loss) from operations 631 (260 ) 371 (961 ) 3,318 6,747 (12,523 ) (253 ) Loss on derivatives — (6,428 ) (6,428 ) (129 ) — — — — Loss on extinguishment of debt — — — — — (7,962 ) — — Net gain on disposals — — — — — 66,705 — — Provision for taxes — (876 ) (876 ) — — — — — Net income (loss) $ 631 $ (7,564 ) $ (6,933 ) $ (1,090 ) $ 3,318 $ 65,490 $ (12,523 ) $ (253 ) Company’s share in net income (loss) $ (444 ) $ (1,386 ) $ (1,830 ) $ (273 ) $ 2,655 $ 50,424 $ (641 ) $ — Adjustments for REIT basis 455 — 455 — (461 ) (54,390 ) — — Company’s equity in net income (loss) within continuing operations $ 11 $ (1,386 ) $ (1,375 ) $ (273 ) $ 2,194 $ (3,966 ) $ (641 ) $ — 1. On May 31, 2016, the Gramercy European Property Fund acquired a 20.0% interest in the Goodman Europe JV and on June 30, 2016, the Gramercy European Property Fund acquired 74.9% of the Company’s 80.0% % interest in the Goodman Europe JV. As of September 30, 2016 , the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the nine months ended September 30, 2016 , the Company’s equity in net income (loss) from the entities is based on these ownership percentages during the period. 2. Includes the Philips JV, the Morristown JV, and European Fund Carry Co.

Debt Obligations

Debt Obligations	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt Obligations	Debt Obligations Secured Debt Mortgage Notes Certain real estate assets are subject to mortgage notes. During the nine months ended September 30, 2017 , the Company assumed $114,649 of non-recourse mortgages in connection with five real estate acquisitions. During the year ended December 31, 2016 , the Company assumed $244,188 of non-recourse mortgages in connection with 27 real estate acquisitions. During the three and nine months ended September 30, 2017 , the Company paid off the mortgage notes on two properties. During the nine months ended September 30, 2017 , the Company refinanced the debt on two properties encumbered by a mortgage loan for $10,456 and subsequently transferred the mortgage on these two properties to the buyer of the properties. During the three and nine months ended September 30, 2017 , the Company recorded a net gain on the early extinguishment of mortgage debt of $0 and $60 , respectively. During the three and nine months ended September 30, 2016 , the Company paid off the mortgage notes on 14 and 22 properties, respectively, and during the nine months ended September 30, 2016 , the Company transferred one property encumbered by a mortgage note. Additionally, during the three months ended September 30, 2016 the Company defeased a mortgage note with an outstanding principal balance of $124,605 that encumbered 11 properties, through the purchase of treasury securities valued at $144,063 , which were immediately sold following the transaction. For the three and nine months ended September 30, 2016 , the Company recorded net losses on early extinguishment of debt of $13,777 and $20,890 , including net gains on extinguishment of debt of $0 and $1,930 within discounted operations, respectively, related to unamortized deferred financing costs and mortgage premiums and discounts that were immediately expensed upon termination as well as early termination fees and other costs incurred related to the extinguishments. The Company’s mortgage notes include a series of financial and other covenants with which the Company must comply in order to borrow under them. The Company was in compliance with the covenants under the mortgage note facilities as of September 30, 2017 . The following is a summary of the Company’s secured financing arrangements as of September 30, 2017 and December 31, 2016 : Property Interest Rate 1 Maturity Date Outstanding Balance September 30, 2017 December 31, 2016 Dallas, TX 2 3.05% 3/1/2018 $ 9,372 $ 9,540 Jacksonville, FL 2 3.05% 3/1/2018 6,732 6,852 Cincinnati, KY 2 3.29% 3/1/2018 6,512 6,628 Minneapolis, MN 2 3.05% 3/1/2018 5,896 6,001 Phoenix, AZ 2 3.05% 3/1/2018 4,048 4,120 Ames, IA 5.05% 5/1/2018 16,069 16,436 Columbus, OH 4.01% 5/31/2018 19,006 19,708 Greenwood, IN 3.59% 6/15/2018 7,302 7,436 Greenfield, IN 3.63% 6/15/2018 5,902 6,010 Logistics Portfolio - Pool 3 3 3.96% 8/1/2018 43,300 43,300 Philadelphia, PA 4.99% 1/1/2019 12,041 12,328 Columbus, OH 3.94% 1/31/2019 5,768 5,908 Bridgeview, IL 3.90% 5/1/2019 5,883 6,014 Spartanburg, SC 3.20% 6/1/2019 732 1,025 Charleston, SC 3.11% 8/1/2019 591 986 Lawrence, IN 5.02% 1/1/2020 20,224 20,703 Charlotte, NC 3.28% 1/1/2020 1,711 2,217 Hawthorne, CA 3.52% 8/1/2020 17,327 17,638 Charleston, SC 3.32% 10/1/2020 820 1,001 Charleston, SC 2.97% 10/1/2020 806 984 Charleston, SC 3.37% 10/1/2020 806 984 Charlotte, NC 3.38% 10/1/2020 700 853 Des Plaines, IL 5.54% 10/31/2020 2,405 2,463 Waco, TX 4.75% 12/19/2020 14,964 15,187 Deerfield, IL 3.71% 1/1/2021 10,538 10,804 Winston-Salem, NC 3.41% 6/1/2021 3,569 4,199 Winston-Salem, NC 3.42% 7/1/2021 1,184 1,388 Logistics Portfolio - Pool 1 3 4.27% 1/1/2022 38,355 39,002 CCC Portfolio 3 4.24% 10/6/2022 22,933 23,280 Logistics Portfolio - Pool 4 3 4.36% 12/5/2022 79,500 79,500 KIK USA Portfolio 3 4.31% 7/6/2023 7,230 7,450 Yuma, AZ 5.27% 12/6/2023 11,909 12,058 Allentown, PA 5.16% 1/6/2024 22,790 23,078 Spartanburg, SC 3.72% 2/1/2024 5,821 6,360 Maple Grove, MN 3.88% 5/6/2024 16,468 — Curtis Bay, MD 4.31% 7/1/2024 13,500 — Rialto, CA 3.91% 8/1/2024 54,940 — Durham, NC 4.02% 9/6/2024 3,648 — Houston, TX 3.68% 9/1/2024 26,000 — Charleston, SC 3.80% 2/1/2025 6,169 6,658 Hackettstown, NJ 5.49% 3/6/2026 9,488 9,550 Hutchins, TX 5.41% 6/1/2029 21,883 22,764 Logistics Portfolio - Pool 2 3 4.48% 1/1/2041 35,711 36,279 Buford, GA 4.67% 7/1/2017 — 15,512 Woodcliff Lake, NJ 3.04% 9/15/2017 — 35,366 KIK Canada Portfolio 3 3.57% 5/5/2019 — 7,914 Total mortgage notes payable $ 600,553 $ 555,484 Net deferred financing costs and net debt premium 6,345 3,158 Total mortgage notes payable, net $ 606,898 $ 558,642 1. Represents the interest rate as of September 30, 2017 or date of extinguishment if the mortgage note was extinguished during the period, that was recorded for financial reporting purposes, which reflects the effect of interest rate swaps and amortization of financing costs and fair market value premiums or discounts. 2. These five mortgage notes are cross-collateralized. 3. There are two properties under the Logistics Portfolio - Pool 3 mortgage, three properties under the Logistics Portfolio - Pool 1 mortgage, five properties under the CCC Portfolio mortgage, six properties under the Logistics Portfolio - Pool 4 mortgage, three properties under the KIK USA Portfolio mortgage, five properties under the Logistics Portfolio - Pool 2 mortgage, and two properties under the KIK Canada Portfolio mortgage. Unsecured Debt 2015 Credit Facility and Term Loans In December 2015, the Company entered into an agreement, or the Credit Agreement, for a new $1,900,000 credit facility, or the 2015 Credit Facility, consisting of an $850,000 senior unsecured revolving credit facility, or the 2015 Revolving Credit Facility, and $1,050,000 term loan facility with JPMorgan Securities LLC and Merrill Lynch, Pierce, Fenner and Smith Incorporated and terminated Legacy Gramercy's 2014 Credit Facility. The 2015 Revolving Credit Facility consists of a $750,000 U.S. dollar revolving credit facility and a $100,000 multicurrency revolving credit facility. The 2015 Revolving Credit Facility matures in January 2020, but may be extended for two additional six month periods upon the payment of applicable fees and satisfaction of certain customary conditions. The term loan facility, or the 2015 Term Loan, consists of a $300,000 term loan facility that matures in January 2019 with one 12-month extension option, or the 3-Year Term Loan, and a $750,000 term loan facility that matures in January 2021, or the 5-Year Term Loan. Outstanding borrowings under the 2015 Revolving Credit Facility incur interest at a floating rate based upon, at the Company’s option, either (i) adjusted London Interbank Offered Rate, or LIBOR, plus an applicable margin ranging from 0.875% to 1.55% , depending on the Company’s credit ratings, or (ii) the alternate base rate plus an applicable margin ranging from 0.00% to 0.55% , depending on the Company’s credit ratings. The Company is also required to pay quarterly in arrears a 0.125% to 0.30% facility fee, depending on the Company's credit ratings, on the total commitments under the 2015 Revolving Credit Facility. Outstanding borrowings under the 2015 Term Loan incur interest at a floating rate based upon, at the Company’s option, either (i) adjusted LIBOR plus an applicable margin ranging from 0.90% to 1.75% , depending on the Company’s credit ratings, or (ii) the alternate base rate plus an applicable margin ranging from 0.00% to 0.75% , depending on the Company’s credit ratings. The alternate base rate is the greater of (x) the prime rate announced by JPMorgan Chase Bank, N.A., (y) 0.50% above the Federal Funds Effective Rate and (z) the adjusted LIBOR for a one-month interest period plus 1.00% . In December 2015, the Company also entered into a $175,000 seven -year unsecured term loan with Capital One, N.A., or the 7-Year Term Loan, which matures in January 2023. Outstanding borrowings under the 7-Year Term Loan incur interest at a floating rate based upon, at the Company’s option, either (i) adjusted LIBOR plus an applicable margin ranging from 1.30% to 2.10% , depending on the Company’s credit ratings, or (iii) the alternate base rate plus an applicable margin ranging from 0.30% to 1.10% , depending on the Company’s credit ratings. The alternate base rate is the greatest of (x) the prime rate announced by Capital One, (y) 0.50% above the Federal Funds Effective Rate, and (z) the adjusted LIBOR for a one-month interest period plus 1.00% . The Company’s unsecured borrowing facilities include a series of financial and other covenants that the Company has to comply with in order to borrow under the facilities. The Company was in compliance with the covenants under the facilities as of September 30, 2017 . Refer to the table at the end of Note 6 for specific terms and the Company’s outstanding borrowings under the facilities. Senior Unsecured Notes During 2015 and 2016, the Company issued and sold an aggregate $500,000 principal amount of senior unsecured notes payable in private placements, which have maturities ranging from 2022 through 2026 and bear interest semiannually at rates ranging from 3.89% to 4.97% . Refer to the table later in Note 6 for specific terms of the Company's Senior Unsecured Notes. Exchangeable Senior Notes On March 18, 2014, the Company issued $115,000 of 3.75% Exchangeable Senior Notes. The Exchangeable Senior Notes were senior unsecured obligations of a subsidiary of the Operating Partnership and were guaranteed by the Company on a senior unsecured basis. During June 2017, the Exchangeable Senior Notes became redeemable at the option of the Company. In August 2017, the Company announced its intention to call for redemption the Exchangeable Senior Notes. As a result of the Company’s call for redemption, the holders exchanged 100.0% of the Exchangeable Senior Notes for 5,258,420 of the Company’s common shares in September 2017. As of September 30, 2017, there were no Exchangeable Senior Notes outstanding. The fair value of the Exchangeable Senior Notes was determined at issuance to be $106,689 and the discount on the Exchangeable Senior Notes was being amortized to interest expense over their expected life. Upon exchange in September 2017, the Company remeasured the Exchangeable Senior Notes to fair value of $117,450 and then recognized a loss on extinguishment of debt of $6,751 to write them off during the three and nine months ended September 30, 2017 , representing the change in fair value and the amount of the unamortized discount and deferred financing costs at the time of exchange. Additionally, during the three and nine months ended September 30, 2017 , the Company recorded $42,065 to additional paid in capital in shareholders’ equity related to the extinguishment, representing the difference between the fair value of the debt and equity components of the Exchangeable Senior Notes. As of September 30, 2017 , there was no remaining value recorded for the Exchangeable Senior Notes on the Company’s Condensed Consolidated Balance Sheets. As of December 31, 2016, the Exchangeable Senior Notes were recorded as a liability at carrying value $108,832 , net of unamortized discount and deferred financing costs of $6,168 and the fair value of the Exchangeable Senior Notes’ embedded exchange option of $11,726 was recorded in additional paid-in-capital. The terms of the Company’s unsecured debt obligations and outstanding balances as of September 30, 2017 and December 31, 2016 are set forth in the table below: Stated Interest Rate Effective Interest Rate 1 Maturity Date Outstanding Balance September 30, 2017 December 31, 2016 2015 Revolving Credit Facility - U.S. dollar tranche 2.20 % 2.20 % 1/8/2020 $ 595,000 $ — 2015 Revolving Credit Facility - Multicurrency tranche 1.20 % 1.20 % 1/8/2020 $ 20,097 $ 65,837 3-Year Term Loan 2.35 % 2.33 % 1/8/2019 300,000 300,000 5-Year Term Loan 2.35 % 2.70 % 1/8/2021 750,000 750,000 7-Year Term Loan 2.76 % 3.34 % 1/9/2023 175,000 175,000 2015 Senior Unsecured Notes 4.97 % 5.07 % 12/17/2024 150,000 150,000 2016 Senior Unsecured Notes 3.89 % 4.00 % 12/15/2022 150,000 150,000 2016 Senior Unsecured Notes 4.26 % 4.38 % 12/15/2025 100,000 100,000 2016 Senior Unsecured Notes 4.32 % 4.43 % 12/15/2026 100,000 100,000 Exchangeable Senior Notes 2 3.75 % 6.36 % 9/15/2017 — 115,000 Total unsecured debt 2,340,097 1,905,837 Net deferred financing costs and net debt discount (3,316 ) (9,704 ) Total unsecured debt, net $ 2,336,781 $ 1,896,133 1. Represents the rate at which interest expense is recorded for financial reporting purposes as of September 30, 2017 , which reflects the effect of interest rate swaps and amortization of financing costs and fair market value premiums or discounts. 2. During September 2017, the Exchangeable Senior Notes were exchanged for the Company’s common shares. Thus, they have no outstanding balance as of September 30, 2017 . Combined aggregate principal maturities of the Company’s unsecured debt obligations, non-recourse mortgages, and Exchangeable Senior Notes, in addition to associated interest payments, as of September 30, 2017 are as follows: October 1 to December 31, 2017 2018 2019 2020 2021 Thereafter Above market interest Total 2015 Revolving Credit Facility $ — $ — $ — $ 615,097 $ — $ — $ — $ 615,097 Term Loans — — 300,000 — 750,000 175,000 — 1,225,000 Mortgage Notes Payable 1 4,073 171,988 35,003 61,803 18,153 309,533 — 600,553 Senior Unsecured Notes — — — — — 500,000 — 500,000 Interest Payments 2 28,780 94,453 86,650 69,801 44,158 43,378 3,029 370,249 Total $ 32,853 $ 266,441 $ 421,653 $ 746,701 $ 812,311 $ 1,027,911 $ 3,029 $ 3,310,899 1. Mortgage note payments reflect accelerated repayment dates, when applicable, pursuant to related the loan agreement. 2. Interest payments do not reflect the effect of interest rate swaps.

Leasing Agreements

Leasing Agreements	9 Months Ended
	Sep. 30, 2017
Leases, Operating [Abstract]
Leasing Agreements	Leasing Agreements The Company’s properties are leased to tenants under operating leases with expiration dates extending through the year 2042 . These leases generally contain rent increases and renewal options. Future minimum rental revenues under non-cancelable leases excluding reimbursements for operating expenses as of September 30, 2017 are as follows: October 1 to December 31, 2017 2018 2019 2020 2021 Thereafter Total minimum lease rental income Operating Leases $ 112,429 $ 450,096 $ 424,686 $ 396,516 $ 362,870 $ 1,973,979 $ 3,720,576

Transactions with Trustee Relat

Transactions with Trustee Related Entities and Related Parties	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Transactions with Trustee Related Entities and Related Parties	Transactions with Trustee Related Entities and Related Parties In December 2016, the Company sold its 5.1% interest in one property located in Lille, France held by the Goodman Europe JV to the Gramercy European Property Fund, in which the Company had a 14.2% ownership interest, for gross proceeds of $2,662 ( €2,563 ). In July 2017 , the Gramercy European Property Fund sold 100.0% of its assets to an unrelated third party. Refer to Note 5 for more information on the sale transaction. On June 30, 2016, the Company sold 74.9% of its outstanding 80.0% interest in the Goodman Europe JV to the Gramercy European Property Fund for gross proceeds of $148,884 ( €134,336 ), based on third-party valuations for the underlying properties. The Company’s sale of 74.9% of its interest in the Goodman Europe JV resulted in the Company recording a gain of $5,341 during the period, primarily related to depreciation and amortization recorded since Merger closing date. Following the sale transaction, the Company had a 5.1% continuing direct interest in the Goodman Europe JV, which has since been sold. The transaction was entered into in order to achieve efficiencies from the combination of the two European platforms. The Company made cumulative contributions of $55,892 ( €50,000 ) to the Gramercy European Property Fund from inception through July 2017, when the Gramercy European Property Fund’s assets were sold. Refer to Note 5 for more information on the sale. The Company’s CEO, Gordon F. DuGan, was on the board of directors of the Gramercy European Property Fund prior to its sale in July 2017 and committed and fully funded approximately $1,388 ( €1,250 ) in capital to the Gramercy European Property Fund. The two Managing Directors of Gramercy Europe Asset Management collectively committed and fully funded approximately $1,388 ( €1,250 ) in capital to the Gramercy European Property Fund prior to the sale of its assets in July 2017. One of the properties acquired in December 2015 as part of the Merger was partially leased to Duke Realty, the Company’s partner in the Duke JV. Duke Realty acted as the managing member of the Duke JV, which was dissolved in July 2016 as described in Note 5, and as such provided asset management, construction, development, leasing and property management services, for which it was entitled to fees as well as a promoted interest. From the date of the Merger through lease expiration in May 2016, Duke Realty leased 30,777 square feet of one of the Company’s office properties located in Minnesota which had an aggregate 322,551 rentable square feet. Duke Realty paid the Company $333 under the lease for the nine months ended September 30, 2016 . See Note 5 for more information on the Company’s transactions with the Duke JV.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements ASC 820-10, “Fair Value Measurements and Disclosures,” among other things, establishes a hierarchical disclosure framework associated with the level of pricing observability utilized in measuring financial instruments and other assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, or an exit price. The Company discloses fair value information, whether or not recognized in the financial statements, for which it is practicable to estimate that value. In cases where quoted market prices are not available, fair values are based upon the application of discount rates to estimated future cash flows based upon market yields or by using other valuation methodologies. Considerable judgment is necessary to interpret market data and develop estimated fair value. Accordingly, fair values are not necessarily indicative of the amounts the Company could realize on disposition of the financial instruments and other assets and liabilities measured at fair value. The use of different market assumptions and/or estimation methodologies may have a material effect on estimated fair value amounts. The level of pricing observability generally correlates to the degree of judgment utilized in measuring the fair value of financial instruments and other assets and liabilities. The three broad levels defined are as follows: Level I - This level is comprised of financial instruments and other assets and liabilities that have quoted prices that are available in liquid markets for identical assets or liabilities. Level II - This level is comprised of financial instruments and other assets and liabilities for which quoted prices are available but which are traded less frequently and instruments that are measured at fair value using management’s judgment, where the inputs into the determination of fair value can be directly observed. Level III - This level is comprised of financial instruments and other assets and liabilities that have little to no pricing observability as of the reported date. These financial instruments do not have active markets and are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment and assumptions. The following table presents the carrying value in the financial statements and approximate fair value of assets and liabilities measured on a recurring and nonrecurring basis at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value Financial assets: Interest rate swaps $ 8,243 $ 8,243 $ 3,769 $ 3,769 Retained CDO Bonds 6,167 6,167 11,906 11,906 Investment in CBRE Strategic Partners Asia 2,772 2,772 4,145 4,145 Real estate investments 1 14,561 14,561 2,413 2,413 Financial liabilities: Interest rate swaps $ 391 $ 391 $ 700 $ 700 Long-term debt 2015 Revolving Credit Facility 2 615,097 612,120 65,837 65,897 3-Year Term Loan 2 300,000 299,180 300,000 300,213 5-Year Term Loan 2 750,000 744,851 750,000 750,959 7-Year Term Loan 2 175,000 176,516 175,000 172,850 Mortgage notes payable 2 606,898 618,097 558,642 567,705 Senior Unsecured Notes 2 496,684 508,547 496,464 498,650 Exchangeable Senior Notes 2 — — 108,832 115,625 1. Amounts as of September 30, 2017 and December 31, 2016 represent four and one real estate investments, respectively, that were impaired during the nine months ended September 30, 2017 and the year ended December 31, 2016 , respectively, and were owned as of the end of the respective reporting periods. 2. Long-term debt instruments are classified as Level III due to the significance of unobservable inputs which are based upon management assumptions. The following methods and assumptions were used to estimate the fair value of each class of assets and liabilities for which it is practicable to estimate the value: Cash and cash equivalents, marketable securities, accrued interest, and accounts payable: These balances in the Condensed Consolidated Financial Statements reasonably approximate their fair values due to the short maturities of these items. Retained CDO Bonds: Non-investment grade, subordinate CDO bonds, preferred shares and ordinary shares are presented in other assets on the Condensed Consolidated Financial Statements at fair value, which is determined on a quarterly basis using an internally developed discounted cash flow model. CBRE Strategic Partners Asia: The investment manager of CBRE Strategic Partners Asia applies valuation techniques for the Company’s investment carried at fair value based upon the application of the income approach, the direct market comparison approach, the replacement cost approach or third-party appraisals to the underlying assets held in the unconsolidated entity in determining the net asset value attributable to the Company’s ownership interest therein. Refer to Note 5 for more information on this investment. Real estate investments: Real estate investments impaired during a period are reported at estimated fair value and real estate investments impaired during a period that are classified as held for sale as of the end of the period are reported at estimated fair value less costs to sell. Derivative instruments: The Company’s derivative instruments, which are comprised of interest rate swap agreements, are carried at fair value in the Condensed Consolidated Financial Statements based upon third-party valuations. Derivative fair values are presented within other assets or other liabilities, depending on the balance at the end of the period. Changes in fair value of derivative instruments that represent realized gains (losses) are recorded within interest expense on the Condensed Consolidated Statements of Operations. Refer to Note 10 for more information on the derivative instruments. Mortgage notes payable, unsecured term loans, unsecured revolving credit facilities and senior unsecured notes: These instruments are presented in the Condensed Consolidated Financial Statements at amortized cost and not at fair value. The fair value of each instrument is estimated by a discounted cash flows model, using discount rates that best reflect current market rates for financings with similar characteristics and credit quality. Mortgage premiums and discounts are amortized to interest expense on the Condensed Consolidated Statements of Operations using the effective interest method over the terms of the related notes. Refer to Note 6 for more information on these instruments. Exchangeable Senior Notes: The Exchangeable Senior Notes are presented at amortized cost on the Condensed Consolidated Financial Statements. The fair value is determined based upon a discounted cash-flow methodology using discount rates that best reflect current market rates for instruments with similar with characteristics and credit quality. Refer to Note 6 for more information on these instruments. Disclosure about fair value measurements is based on pertinent information available to the Company at the reporting date. Although the Company is not aware of any factors that would significantly affect the reasonable fair value amounts, such amounts have not been comprehensively revalued for the purpose of these financial statements since September 30, 2017 and December 31, 2016 , and current estimates of fair value may differ significantly from the amounts presented herein. The following discussion of fair value was determined by the Company using available market information and appropriate valuation methodologies. Considerable judgment is necessary to interpret market data and develop estimated fair value. Accordingly, fair values are not necessarily indicative of the amounts the Company could realize on disposition of the assets or liabilities. Determining which category an asset or liability falls within the hierarchy requires significant judgment and the Company evaluates its hierarchy disclosures each quarter. Assets and liabilities measured at fair value on a recurring basis and on a non-recurring basis are categorized in the table below based upon the lowest level of significant input to the valuations. At September 30, 2017 Total Level I Level II Level III Financial Assets: Retained CDO Bonds $ 6,167 $ — $ — $ 6,167 Real estate investments 14,561 — — 14,561 Investment in CBRE Strategic Partners Asia 2,772 — — 2,772 Interest rate swaps 8,243 — — 8,243 $ 31,743 $ — $ — $ 31,743 Financial Liabilities: Interest rate swaps $ (391 ) $ — $ — $ (391 ) $ (391 ) $ — $ — $ (391 ) At December 31, 2016 Total Level I Level II Level III Financial Assets: Retained CDO Bonds $ 11,906 $ — $ — $ 11,906 Real estate investments 2,413 — — 2,413 Investment in CBRE Strategic Partners Asia 4,145 — — 4,145 Interest rate swaps 3,769 — — 3,769 $ 22,233 $ — $ — $ 22,233 Financial Liabilities: Interest rate swaps $ (700 ) $ — $ — $ (700 ) $ (700 ) $ — $ — $ (700 ) Valuation of Level III Instruments Retained CDO Bonds: Retained CDO Bonds are valued on a recurring basis using an internally developed discounted cash flow model. Management estimates the timing and amount of cash flows expected to be collected and applies a discount rate equal to the yield that the Company would expect to pay for similar securities with similar risks at the valuation date. Future expected cash flows generated by management require significant assumptions and judgment regarding the expected resolution of the underlying collateral, which primarily consists of commercial mortgage backed securities. The resolution of the underlying collateral requires further management assumptions regarding timing of workouts and recoveries, loan loss severities and other factors. The models are most sensitive to the unobservable inputs such as the amount of the recoveries of the underlying securities. Significant increases (decreases) in any of those inputs in isolation as well as any change in the expected timing of those inputs would result in a significantly lower (higher) fair value measurement. Due to the inherent uncertainty in the determination of fair value, the Company has designated its Retained CDO Bonds as Level III. Investment in CBRE Strategic Partners Asia: The Company’s investment in CBRE Strategic Partners Asia is based on the Level III valuation inputs applied by the investment manager of CBRE Strategic Partners Asia, utilizing a mix of different approaches for valuing the underlying real estate related investments within the investment company. The approaches include the income approach, direct market comparison approach and the replacement cost approach for newer properties. For investments owned more than one year, except for investments under construction or incurring significant renovation, CBRE Strategic Partners Asia obtains a third-party appraisal. For investments in real estate under construction or incurring significant renovation, the valuation analysis is prepared by the investment manager of CBRE Strategic Partners Asia. The valuations are most sensitive to the unobservable inputs of discount rates, as well as capitalization rates an expected future cash flows, and significant increases (decreases) in these inputs would result in a significantly lower (higher) fair value measurement. The fund’s term ended in January 2017 and commencement of the fund's liquidation was filed in early February 2017. The fund will wind up over the succeeding 24 months. Real estate investments: Real estate investments impaired during a period are reported at estimated fair value and real estate investments impaired during a period that are classified as held for sale as of the end of the period are reported at estimated fair value less costs to sell. The fair value of real estate investments and their related lease intangibles is determined using third-party valuation support, including purchase-sale contracts and other available market information. Key assumptions in the valuations, to which the fair value determinations are most sensitive, include discount and capitalization rates as well as expected future cash flows. Significant increases (decreases) in these inputs would result in a significantly lower (higher) fair value measurement. As the inputs are unobservable, the Company determined the inputs used to value this liability falls within Level III for fair value reporting. Derivative instruments: Interest rate swaps are valued with the assistance of a third-party derivative specialist using a discounted cash flow model, which requires a combination of observable market-based inputs, such as interest rate curves, and unobservable inputs which require significant judgment such as the credit valuation adjustments due to the risk of nonperformance by both the Company and its counterparties. The most significant unobservable input in the fair valuation of derivative instruments is the credit valuation adjustment as it requires significant management judgment regarding changes in the credit risk of the Company or its counterparties, however the primary driver of the fair value of the interest rate swaps is the forward interest rate curve. Total unrealized gains from derivatives for the three and nine months ended September 30, 2017 were $2,959 and $4,645 , respectively, in accumulated other comprehensive income. Total unrealized gains (losses) from derivatives for the three and nine months ended September 30, 2016 were $7,653 and $(25,996) , respectively, in accumulated other comprehensive income. Fair Value on a Recurring Basis Quantitative information regarding the valuation techniques and the range of significant unobservable Level III inputs used to determine fair value measurements on a recurring basis as of September 30, 2017 are as follows: Financial Asset (Liability) Fair Value Valuation Technique Unobservable Inputs Range Non-investment grade, subordinate CDO bonds $ 6,167 Discounted cash flows Discount rate 16.5% Interest rate swaps 1 7,852 Hypothetical derivative method Credit borrowing spread 135 to 205 basis points Investment in CBRE Strategic Partners Asia 2,772 Discounted cash flows Discount rate 20.0% 1. Fair value includes interest rate swap liabilities with an aggregate value of $(391) . The following rollforward table reconciles the beginning and ending balances of financial assets (liabilities) measured at fair value on a recurring basis using Level III inputs as of September 30, 2017 : Retained CDO Bonds Investment in CBRE Strategic Partners Asia Interest Rate Swaps Total Financial Assets (Liabilities) - Level III Balance at January 1, 2017 $ 11,906 $ 4,145 $ 3,069 $ 19,120 Amortization of discounts or premiums 1,353 — — 1,353 Adjustments to fair value: Ineffective portion of change in derivative instruments — — 138 138 Unrealized gain on derivatives — — 4,645 4,645 Unrealized loss in other comprehensive income from fair value adjustment (2,202 ) — — (2,202 ) Other-than-temporary impairments (4,890 ) — — (4,890 ) Total loss on fair value adjustments — (561 ) — (561 ) Distributions from financial assets — (812 ) — (812 ) Balance at September 30, 2017 $ 6,167 $ 2,772 $ 7,852 $ 16,791 Fair Value on a Non-Recurring Basis The Company measured its real estate investments impaired during the period, including both assets classified as held for sale and assets held for investment, on a non-recurring basis as of September 30, 2017 and December 31, 2016 . The Company recorded impairment on these assets as a result of a change in intent to hold the real estate investments. Real estate investments impaired during the period are reported at estimated fair value and real estate investments impaired during the period that are classified as held for sale as of the end of the period are reported at estimated fair value less costs to sell. The Company measured four assets on a non-recurring basis as of September 30, 2017 , of which two were classified as held for investment with a total value of $10,400 and two were classified as held for sale with a value of $4,161 as of September 30, 2017 . The Company measured one asset on a non-recurring basis as of December 31, 2016 , which was classified as held for investment and recorded at $2,413 as of December 31, 2016 .

Derivatives and Non-Derivative

Derivatives and Non-Derivative Hedging Instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Non-Derivative Hedging Instruments	Derivatives and Non-Derivative Hedging Instruments In the normal course of business, the Company is exposed to the effect of interest rate changes and foreign exchange rate changes. The Company limits these risks by following established risk management policies and procedures including the use of derivatives and net investment hedges. The Company uses a variety of derivative instruments to manage, or hedge, interest rate risk. The Company enters into hedging and derivative instruments that will be maximally effective in reducing the interest rate risk and foreign currency exchange rate risk exposure that they are designated to hedge. This effectiveness is essential for qualifying for hedge accounting. Instruments that meet these hedging criteria are formally designated as hedges at the inception of the derivative contract. The Company uses a variety of commonly used derivative products that are considered “plain vanilla” derivatives. These derivatives typically include interest rate swaps, caps, collars and floors. The Company expressly prohibits the use of unconventional derivative instruments and using derivative instruments for trading or speculative purposes. Further, the Company has a policy of only entering into contracts with major financial institutions based upon their credit ratings and other factors. The Company recognizes all derivatives on the Condensed Consolidated Balance Sheets at fair value within other assets or other liabilities, depending on the balance at the end of the period. Derivatives that are not designated as hedges must be adjusted to fair value through income. If a derivative is a hedge, depending on the nature of the hedge, changes in the fair value of the derivative will either be offset against the change in fair value of the hedged asset, liability or firm commitment through earnings, or recognized in other comprehensive income until the hedged item is recognized in earnings. The ineffective portion of a derivative’s change in fair value will be immediately recognized in earnings. Derivative accounting may increase or decrease reported net income and shareholders’ equity prospectively, depending on future levels of the LIBOR swap spreads and other variables affecting the fair values of derivative instruments and hedged items, but will have no effect on cash flows, provided the contract is carried through to full term. Refer to Note 9 for additional information on the Company's derivative instruments, including the fair value measurement of these instruments. Borrowings on the Company’s multicurrency tranche of the 2015 Revolving Credit Facility, which are designated as non-derivative net investment hedges, are recognized at par value based on the exchange rate in effect on the date of the draw. Subsequent changes in the exchange rate of the Company’s non-derivative net investment hedge are recognized as part of the cumulative foreign currency translation adjustment within other comprehensive income. The Company’s derivatives and hedging instruments as of September 30, 2017 are as follows: Benchmark Rate Notional Value Strike Rate Effective Date Expiration Date Fair Value Interest Rate Swap - Waco 1 mo. USD-LIBOR-BBA 14,964 USD 4.55% 12/19/2013 12/19/2020 $ (313 ) Interest Rate Swap - Atrium I 1 mo. USD-LIBOR-BBA 19,006 USD 1.78% 8/16/2011 5/31/2018 (48 ) Interest Rate Swap - Easton III 1 mo. USD-LIBOR-BBA 5,768 USD 1.95% 8/16/2011 1/31/2019 (31 ) Interest Rate Swap - 3-Year Term Loan 1 mo. USD-LIBOR-BBA 100,000 USD 1.22% 12/19/2016 12/17/2018 375 Interest Rate Swap - 3-Year Term Loan 1 mo. USD-LIBOR-BBA 100,000 USD 1.23% 12/19/2016 12/17/2018 370 Interest Rate Swap - 3-Year Term Loan 1 mo. USD-LIBOR-BBA 100,000 USD 1.24% 12/19/2016 12/17/2018 357 Interest Rate Swap - 5-Year Term Loan 1 mo. USD-LIBOR-BBA 750,000 USD 1.60% 12/17/2015 12/17/2020 4,352 Interest Rate Swap - 7-Year Term Loan 1 mo. USD-LIBOR-BBA 175,000 USD 1.82% 12/17/2015 1/9/2023 739 Forward Starting Swap 1 3 mo. USD-LIBOR-BBA 250,000 USD 2.23% 12/20/2017 12/20/2027 2,051 Net Investment Hedge in GBP-denominated investments USD-GBP exchange rate 15,000 GBP N/A 7/15/2016 N/A — Total hedging instruments $ 7,852 1. During the three months ended September 30, 2017, the Company entered into one forward starting swap to hedge the risk of changes in the interest-related cash outflows associated with potential new long-term debt arrangements. The forward starting swap has a mandatory early termination date of March 20, 2018. As of September 30, 2017 , the Company’s derivative instruments consist of interest rate swaps, which are cash flow hedges. Through its interest rate swaps, the Company is hedging exposure to variability in future interest payments on its debt facilities. During the three months ended September 30, 2017, the Company entered into one forward starting swap to hedge the risk of changes in the interest-related cash outflows associated with potential new long-term debt arrangements. At September 30, 2017 , the Company's interest rate swap derivative instruments were reported in other assets at fair value of $8,243 and in other liabilities at fair value of $(391) . Swap gain (loss) is recognized in interest expense in the Condensed Consolidated Statements of Operations and represents interest rate swap hedge ineffectiveness, or amounts excluded from ineffectiveness, which relates to the off-market financing element associated with certain derivatives. Swap gain of $92 and $138 was recognized for the three and nine months ended September 30, 2017 , respectively, and swap gain of $83 and $817 was recognized for the three and nine months ended September 30, 2016 , respectively. During the three and nine months ended September 30, 2017 , the Company reclassified $273 and $812 , respectively, from accumulated other comprehensive income into interest expense related to a derivative terminated in 2015. During the three and nine months ended September 30, 2016 , the Company reclassified $274 and $905 , respectively, from accumulated other comprehensive income into interest expense related to a derivative terminated in 2015. Over time, the realized and unrealized gains and losses held in accumulated other comprehensive income will be reclassified into earnings in the same periods in which the hedged interest payments affect earnings. During the next 12 months, the Company expects that $1,883 will be reclassified from other comprehensive income as an increase in interest expense for the Company’s interest rate swaps as of September 30, 2017 . Additionally, the Company will recognize $1,837 in interest expense on a straight-line basis over the remaining original term of terminated swaps through June 2019, representing amortization of the remaining accumulated other comprehensive income balance related to the swap, and of this amount $1,087 will be recognized in interest expense during the next 12 months. The Company hedges its investments based in foreign currencies using non-derivative net investment hedges in conjunction with borrowings under the multicurrency tranche of its 2015 Revolving Credit Facility. The Company’s non-derivative net investment hedge on its euro-denominated investments, which was entered into in September 2015, was used to hedge exposure to changes in the euro U.S. dollar exchange rate underlying its unconsolidated equity investments in the Gramercy European Property Fund and the Goodman Europe JV, both of which had euros as their functional currency. The Company terminated its euro-denominated non-derivative net investment hedge during the third quarter of 2017 in connection with the sale of its euro-denominated investments, which are discussed in detail in Note 5. The Company’s non-derivative net investment hedge on its British pound sterling-denominated investments, which was entered into in July 2016, is used to hedge exposure to changes in the British pound sterling U.S. dollar exchange rate underlying its unconsolidated equity investment in the Goodman UK JV and its wholly-owned property in Coventry, UK until its disposition in December 2016, both of which have British pounds sterling as their functional currency. At September 30, 2017 , the non-derivative net investment hedge value is reported at carrying value as a net liability of $20,097 , which is included in the balance of the senior unsecured revolving credit facility on the Condensed Consolidated Balance Sheets. In connection with the sale of its euro-denominated investments and termination of the related non-derivative net investment hedge, the Company reclassified $1,851 from accumulated other comprehensive income in earnings representing the accumulated foreign currency translation adjustments recorded since inception of the hedges. During the three and nine months ended September 30, 2017 , the Company recorded a net gain (loss) of $891 and $(4,228) , respectively, in other comprehensive income from the impact of exchange rates related to the non-derivative net investment hedges. During the three and nine months ended September 30, 2016 , the Company recorded a net loss of $109 and $175 , respectively, in other comprehensive income from the impact of exchange rates related to the non-derivative net investment hedges. When the non-derivative net investments being hedged are sold or substantially liquidated, the balance of the translation adjustment accumulated in other comprehensive income will be reclassified into earnings.

Shareholders' Equity (Deficit)

Shareholders' Equity (Deficit) of the Company	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Shareholders' Equity (Deficit) of the Company	Shareholders’ Equity (Deficit) of the Company As of September 30, 2017 and December 31, 2016 , the Company's authorized capital shares consists of 500,000,000 shares of beneficial interest, $0.01 par value per share, of which the Company is authorized to issue up to 490,000,000 common shares of beneficial interest, $0.01 par value per share, or common shares, and 10,000,000 preferred shares of beneficial interest, $0.01 par value per share, or preferred shares. As of September 30, 2017 , 160,669,468 common shares and 3,500,000 preferred shares were issued and outstanding. During the nine months ended September 30, 2017 , the Company’s common dividends are as follows: Quarter Ended Record Date Payment Date Common dividend per share March 31, 2017 3/31/2017 4/14/2017 $ 0.375 June 30, 2017 6/30/2017 7/14/2017 $ 0.375 September 30, 2017 9/30/2017 10/16/2017 $ 0.375 During September 2017, the Company issued 5,258,420 of its common shares to satisfy the exchange of 100.0% of the Exchangeable Senior Notes for 100.0% common shares. In April 2017, the Company completed an underwritten public offering of 10,350,000 common shares, which includes the exercise in full by the underwriters of their option to purchase 1,350,000 additional common shares. The common shares were issued at a public offering price of $27.60 per share and the net proceeds from the offering were approximately $274,234 . In December 2016, the Company's board of trustees approved a 1-for-3 reverse share split of its common shares and outstanding OP Units. The reverse share split was effective after the close of trading on December 30, 2016 and the Company's common shares began trading on a reverse-split-adjusted basis on the NYSE on January 3, 2017. Employee Stock Purchase Plan In June 2017, the Company’s shareholders approved an Employee Stock Purchase Plan, or ESPP, which enables the Company’s eligible employees to purchase the common shares through payroll deductions. The ESPP has a maximum of 250,000 common shares available for issuance and provides for eligible employees to purchase the common shares during defined offer periods at a purchase price determined at the discretion of the board of trustees equal to either (1) a fixed percentage (not less than 85.0% ) of the fair market value of the common shares on the exercise date or (2) the lesser of (A) a fixed percentage (not less than 85.0% ) of the fair market value of the common shares on the exercise date and (B) a fixed percentage (not less than 85.0% ) of the fair market value of the common shares on the first day of the offer period. As of September 30, 2017 , there were no shares issued under the ESPP. Dividend Reinvestment Plan In June 2016, the Company adopted a dividend reinvestment plan, or DRIP, under which shareholders may use their dividends and optional cash payments to purchase additional common shares of the Company. In August 2016, the Company registered 3,333,333 common shares related to the DRIP. During the nine months ended September 30, 2017 , 5,410 shares were issued under the DRIP and as of September 30, 2017 there were 3,327,226 shares available for issuance under the DRIP. Share Repurchase Program In February 2016, the Company’s board of trustees approved a share repurchase program authorizing the Company to repurchase up to $100,000 of the Company’s outstanding common shares. As of September 30, 2017 , the Company had not repurchased any shares under the share repurchase program. At-The-Market Equity Offering Program In July 2016, the Company’s board of trustees approved the establishment of an “at the market” equity issuance program, or ATM Program, pursuant to which the Company may offer and sell common shares with an aggregate gross sales price of up to $375,000 . During the three and nine months ended September 30, 2017 , the Company sold 3,488,525 and 4,219,978 common shares through the ATM Program for net proceeds of approximately $103,351 and $123,051 , respectively. Preferred Shares Holders of the Company's 7.125% Series A Preferred Shares, or Series A Preferred Shares, are entitled to receive annual dividends of $1.78125 per share on a quarterly basis and dividends are cumulative, subject to certain provisions. On or after August 15, 2019, the Company can, at its option, redeem the Series A Preferred Shares at par for cash. At September 30, 2017 , the Company had 3,500,000 of its Series A Preferred Shares outstanding with a mandatory liquidation preference of $25.00 per share. Equity Incentive Plans In June 2016, the Company instituted its 2016 Equity Incentive Plan, which was approved by the Company’s board of trustees and shareholders. As of September 30, 2017 , there were 2,734,009 shares available for grant under the 2016 Equity Incentive Plan. The Company accounts for share-based compensation awards using fair value recognition provisions and assumes an estimated forfeiture rate which impacts the amount of compensation cost recognized over the benefit period. In July 2017, the Company issued a maximum total of 596,460 LTIP Units under its 2016 Equity Incentive Plan. The number of LTIPs Units actually earned by the grantees will be based on the achievement of established performance hurdles with respect to the Company’s actual and relative total shareholder returns during the period from July 1, 2017 through June 30, 2020. Of the earned units, 50.0% will vest on June 30, 2020, and the remaining 50.0% will vest on June 30, 2021, based on continued employment through that date. Vested LTIP Units are convertible on a one-for-one basis into OP Units. The LTIP Units issued in 2017 had an aggregate fair value of $7,800 as of their date of grant, which was calculated in accordance with ASC 718, with share price volatility being one of the primary inputs in the valuation. Through September 30, 2017 , 1,037,759 restricted shares had been issued under the Company’s equity incentive plans, including the 2016 Equity Incentive Plan and the Company’s previous equity incentive plans, of which 66.6% have vested. As of September 30, 2017 and December 31, 2016 , the Company had 352,378 and 318,807 weighted average restricted shares outstanding, respectively. Compensation expense of $655 and $2,227 was recorded for the three and nine months ended September 30, 2017 , respectively, related to the Company’s equity incentive plans. Compensation expense of $614 and $1,701 was recorded for the three and nine months ended September 30, 2016 , respectively, related to the Company’s equity incentive plans. Compensation expense of $4,419 will be recorded over the course of the next 29 months representing the remaining weighted average vesting period of equity awards issued under the equity incentive plans as of September 30, 2017 . Compensation expense of $1,158 and $3,284 was recorded for the three and nine months ended September 30, 2017 , respectively, for the Company's Outperformance Plans. Compensation expense of $488 and $1,464 was recorded for the three and nine months ended September 30, 2016 , respectively, for the Company's Outperformance Plans. Compensation expense of $12,537 will be recorded over the course of the next 41 months , representing the remaining weighted average vesting period of the awards issued under the Outperformance Plans as of September 30, 2017 . Earnings per Share The Company presents both basic and diluted earnings per share, or EPS. Basic EPS is computed by dividing net income available to common shareholders, as adjusted for unallocated earnings attributable to certain participating securities, if any, by the weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common shares were exercised or converted into common shares, as long as their inclusion would not be anti-dilutive. The two-class method is an earnings allocation methodology that determines EPS for common shares and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The Company has certain share-based payment awards that contain nonforfeitable rights to dividends, which are considered participating securities for the purposes of computing EPS pursuant to the two-class method, and therefore the Company applies the two-class method in its computation of EPS. Earnings per share for the three and nine months ended September 30, 2017 and 2016 are computed as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Numerator – Income (loss): Net income (loss) from continuing operations $ 45,607 $ (3,411 ) $ 43,520 $ 14,461 Net income (loss) from discontinued operations (24 ) 347 (76 ) 5,045 Net income (loss) before net gain on disposals 45,583 (3,064 ) 43,444 19,506 Net gain on disposals 4,879 2,336 24,258 2,336 Gain on sale of European unconsolidated equity investment interests held with a related party — — — 5,341 Net Income (loss) 50,462 (728 ) 67,702 27,183 Less: Net income attributable to noncontrolling interest (333 ) (221 ) (374 ) (152 ) Less: Nonforfeitable dividends allocated to participating shareholders (191 ) (196 ) (766 ) (596 ) Less: Preferred share dividends (1,559 ) (1,559 ) (4,676 ) (4,676 ) Net income (loss) available to common shares outstanding - basic $ 48,379 $ (2,704 ) $ 61,886 $ 21,759 Plus: Interest expense on Exchangeable Senior Notes 1,462 — — — Net income (loss) available to common shares outstanding - diluted $ 49,841 $ (2,704 ) $ 61,886 $ 21,759 Denominator – Weighted average shares 1 : Basic weighted average shares outstanding 152,619,352 140,257,503 147,399,457 141,180,822 Effect of dilutive securities: Unvested non-participating share based payment awards 15,052 — 12,709 137,803 Options 21,015 — 18,716 13,802 Outside interests in the Operating Partnership — — — 399,771 Exchangeable Senior Notes 4,851,794 — — 655,511 Diluted weighted average shares outstanding 157,507,213 140,257,503 147,430,882 142,387,709 1. Share and per share amounts have been adjusted for the 1-for-3 reverse share split completed on December 30, 2016. The Company’s options and other share-based payment awards used in the computation of EPS were calculated using the treasury share method. As discussed in Note 6 , 100.0% of the Company’s Exchangeable Senior Notes were exchanged for 5,258,420 of the Company’s common shares in September 2017. Prior to the third quarter of 2017, the Company had the intent and ability to settle the debt component of the Exchangeable Senior Notes in cash and the excess conversion premium in shares, thus for these periods the Company only included the effect of the excess conversion premium in the calculation of Diluted EPS. As the final exchange was completed in all shares, for the three and nine months ended September 30, 2017, the Company used the if-converted method to evaluate the Exchangeable Senior Notes for dilution for the period prior to their conversion. The impact of the Exchangeable Senior Notes is dilutive during the three months ended September 30, 2017 and is therefore included in the calculation of Diluted EPS for the period, however the impact of the Exchangeable Senior Notes is anti-dilutive during the nine months ended September 30, 2017 and is therefore excluded from the calculation of Diluted EPS for the period. The average price of the Company’s common shares for the three and nine months ended September 30, 2016 was above the exchange price of the Exchangeable Senior Notes as of September 30, 2016 . The Company had net loss available to common shares outstanding during the three months ended September 30, 2016, therefore the potential dilutive effect of the excess conversion was excluded from the calculation of Diluted EPS for the period, however the Company had net income available to common shares outstanding during the nine months ended September 30, 2016, therefore, the potential dilutive effect of the excess conversion premium was included in the calculation of Diluted EPS for the period. For the three and nine months ended September 30, 2017 , the net income (loss) attributable to the outside interests in the Operating Partnership have been excluded from the numerator and 1,352,609 and 849,338 , respectively, weighted average shares related to the outside interests in the Operating Partnership has been excluded from the denominator for the purpose of calculating Diluted EPS as there would have been no effect had such amounts been included. Refer to Note 13 for more information on the outside interests in the Operating Partnership. Accumulated other comprehensive income (loss) Accumulated other comprehensive income (loss) as of September 30, 2017 and December 31, 2016 is comprised of the following: September 30, 2017 December 31, 2016 Net unrealized gain (loss) on derivative securities $ 4,205 $ (440 ) Net unrealized gain on debt instruments 1,497 3,699 Foreign currency translation adjustments: Net gain on non-derivative net investment hedges 1 288 4,516 Other foreign currency translation adjustments (5,826 ) (13,045 ) Reclassification of swap gain into interest expense 1,954 1,142 Total accumulated other comprehensive income (loss) $ 2,118 $ (4,128 ) 1. The foreign currency translation adjustment associated with the Company’s non-derivative net investment hedge related to its European investments is included in other comprehensive income (loss). The balance reflects write-offs of $1,851 and $652 on the Company’s non-derivative net investment hedge during the nine months ended September 30, 2017 and the year ended December 31, 2016 , respectively.

Partners' Capital of the Operat

Partners' Capital of the Operating Partnership	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Partners' Capital of the Operating Partnership	Partners’ Capital of the Operating Partnership The Company is the sole general partner of the Operating Partnership. As of September 30, 2017 , the Company owned 160,324,288 of the outstanding general and limited partnership interests, or 98.08% , of the Operating Partnership. The number of common units in the Operating Partnership is equivalent to the number of outstanding common shares of the Company, and the entitlement of all the Operating Partnership’s common units to quarterly distributions and payments in liquidation are substantially the same as those of the Company's common shareholders. Similarly, in the case of each series of preferred units in the Operating Partnership held by the Company, there is a series of preferred shares that is equivalent in number and carries substantially the same terms as such series of the Operating Partnership’s preferred units. Limited Partner Units As of September 30, 2017 , limited partners other than the Company owned 3,131,636 common units, or 1.92% , of the Operating Partnership. Earnings per Unit The Operating Partnership's earnings per unit for the three and nine months ended September 30, 2017 and 2016 are computed as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Numerator – Income (loss): Net income (loss) from continuing operations $ 45,607 $ (3,411 ) $ 43,520 $ 14,461 Net income (loss) from discontinued operations (24 ) 347 (76 ) 5,045 Net income (loss) before net gain on disposals 45,583 (3,064 ) 43,444 19,506 Net gain on disposals 4,879 2,336 24,258 2,336 Gain on sale of European unconsolidated equity investment interests held with a related party — — — 5,341 Net Income (loss) 50,462 (728 ) 67,702 27,183 Less: Net (gain) loss attributable to noncontrolling interest in other partnerships 97 (229 ) 114 (90 ) Less: Nonforfeitable dividends allocated to participating unitholders (191 ) (196 ) (766 ) (596 ) Less: Preferred unit distributions (1,559 ) (1,559 ) (4,676 ) (4,676 ) Net income (loss) available to common units outstanding - basic $ 48,809 $ (2,712 ) $ 62,374 $ 21,821 Plus: Interest expense on Exchangeable Senior Notes 1,462 — — — Net income (loss) available to common units outstanding - diluted $ 50,271 $ (2,712 ) $ 62,374 $ 21,821 Denominator – Weighted average units 1 : Basic weighted average units outstanding 153,971,961 140,596,612 148,248,795 141,580,593 Effect of dilutive securities: Unvested non-participating share based payment awards 15,052 — 12,709 137,803 Options 21,015 — 18,716 13,802 Exchangeable Senior Notes 4,851,794 — — 655,511 Diluted weighted average units outstanding 158,859,822 140,596,612 148,280,220 142,387,709 1. Unit and per unit amounts have been adjusted for the 1-for-3 reverse unit split completed on December 30, 2016.

Noncontrolling Interests

Noncontrolling Interests	9 Months Ended
	Sep. 30, 2017
Noncontrolling Interest [Abstract]
Noncontrolling Interests	Noncontrolling Interests Noncontrolling interests represent the outside equity interests in the Operating Partnership as well as third-party equity interests in the Company’s other consolidated subsidiaries. Outside equity interests in Operating Partnership The outside equity interests in the Operating Partnership include common units of limited partnership interest in the Operating Partnership, or OP Units, and the earned and vested portion of limited partnership interests in the Operating Partnership granted by the Company pursuant to its share-based compensation plans, or LTIP Units, which are convertible on a one-for-one basis into OP Units. The aggregate outstanding noncontrolling interest in the Operating Partnership as of September 30, 2017 represented an interest of approximately 1.92% in the Operating Partnership. A portion of the Operating Partnership’s net income (loss) during each reporting period is attributed to noncontrolling interests based on the weighted average percentage ownership of both OP Unit holders and earned and vested LTIP Unit holders relative to the sum of the Company’s total outstanding common shares, OP Units, and earned and vested LTIP Units. OP Units In September 2017, the Company issued 2,265,829 OP Units in connection with the acquisition of six properties. As of September 30, 2017 , 2,472,121 OP Units were outstanding, which can be redeemed for 2,472,121 of the Company's shares. During the nine months ended September 30, 2017 and the year ended December 31, 2016 , 107,547 and 156,452 OP Units, respectively, were converted on a one-for-one basis into common shares of the Company. At September 30, 2017 , 2,472,121 common shares of the Company were reserved for issuance upon redemption of OP Units. OP Units are recorded at the greater of cost basis or fair market value based on the closing share price of the Company’s common shares at the end of the reporting period. As of September 30, 2017 , the value of the OP units was $75,139 . LTIP Units As of September 30, 2017 , noncontrolling interest owners held 659,515 earned and vested LTIP Units, which, upon conversion into OP Units, can be redeemed for 659,515 of the Company’s common shares. During the nine months ended September 30, 2017 and year ended December 31, 2016 , there were no earned and vested LTIP Units converted into OP Units or redeemed for common shares of the Company. At September 30, 2017 , 659,515 common shares of the Company were reserved for issuance upon conversion of the earned and vested LTIP Units into OP Units and their subsequent redemption for common shares. Below is the rollforward of the activity relating to the noncontrolling interests in the Operating Partnership as of September 30, 2017 : Noncontrolling Interest Balance at January 1, 2017 $ 8,643 Issuance of noncontrolling interests in the Operating Partnership 68,898 Redemption of noncontrolling interests in the Operating Partnership (2,987 ) Net income attribution 488 Fair value adjustments 1,191 Dividends (1,094 ) Balance at September 30, 2017 $ 75,139 Interests in Other Operating Partnerships In connection with the Company’s December 2014 investment in the Gramercy European Property Fund, the Company acquired a 50.0% equity interest in European Fund Manager, which provides investment and asset management services to the Gramercy European Property Fund. European Fund Manager is a consolidated VIE of the Company and is consolidated into its Condensed Consolidated Financial Statements. Refer to Note 2 for further discussion of the VIE and consolidation considerations. As of September 30, 2017 and December 31, 2016 , the value of the Company’s interest in European Fund Manager was $0 and $(321) , respectively. As discussed in Note 5 , following the Gramercy European Property Fund’s sale of its assets in July 2017, European Fund Manager commenced liquidation and will be dissolved over the succeeding months. The Company’s interest in European Fund Manager is presented in the equity section of its Condensed Consolidated Balance Sheets.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Funding Commitments During March 2017, construction was completed on the Company’s build-to-suit property in Round Rock, Texas, which the Company acquired upon completion for $29,605 . As of September 30, 2017 , the Company is obligated to fund the development of three build-to-suit industrial properties, for which it has remaining cumulative future commitments of $46,303 . As of September 30, 2017 and December 31, 2016 , the Company made cumulative contributions to the Gramercy European Property Fund of $55,892 ( €50,000 ). As discussed in Note 5 , in July 2017, the Gramercy European Property Fund sold 100.0% of its assets to a third party. Foreign currency commitments have been converted into U.S. dollars based on (i) the foreign exchange rate at the closing date for completed transactions and (ii) the exchange rate that prevailed on September 30, 2017 , in the case of unfunded commitments. The Company has committed to fund $100,000 to Strategic Office Partners, of which $36,802 and $16,027 was funded as of September 30, 2017 and December 31, 2016, respectively. See Note 5 for further information on the Gramercy European Property Fund and Strategic Office Partners. Legal Proceedings The Company evaluates litigation contingencies based on information currently available, including the advice of counsel and the assessment of available insurance coverage. The Company will establish accruals for litigation and claims when a loss contingency is considered probable and the related amount is reasonably estimable. The Company will periodically review these contingencies which may be adjusted if circumstances change. The outcome of a litigation matter and the amount or range of potential losses at particular points may be difficult to ascertain. If a range of loss is estimated and an amount within such range appears to be a better estimate than any other amount within that range, then that amount is accrued. Legacy Gramercy, its board of directors, and Chambers were named as defendants in various putative class action lawsuits brought by purported Legacy Gramercy stockholders challenging the Merger. The lawsuits were consolidated into a New York state court action, or the New York Action, and a Maryland state court action, or the Maryland Action. On March 1, 2017, the court entered a Final Order and Judgment approving the settlement, awarding plaintiffs’ attorney fees and expenses, and dismissing the New York Action with prejudice. On March 22, 2017, pursuant to the stipulation of settlement, plaintiffs in the Maryland Action filed a notice of dismissal with prejudice with the Circuit Court for Baltimore County, Maryland, which the court entered on April 11, 2017. In connection with the Company’s property acquisitions and the Merger, the Company has determined that there is a risk it will have to pay future amounts to tenants related to continuing operating expense reimbursement audits. In 2017, the Company settled the majority of its operating expense reimbursement audits and paid $3,500 pursuant to the settlement in February 2017. As of September 30, 2017 , the Company has estimated a range of loss of $0 to $360 and determined that its best estimate of total loss is $360 , which is related to the Merger and has been accrued and recorded in other liabilities as of September 30, 2017 and December 31, 2016 . In addition, the Company and/or one or more of its subsidiaries is party to various litigation matters that are considered routine litigation incidental to its business, none of which are considered material. Office Leases The Company has several office locations, which are each subject to operating lease agreements. These office locations include the Company’s corporate office at 90 Park Avenue, New York, New York, and the Company’s seven regional offices located across the United States and Europe. Capital and Operating Ground Leases Certain properties acquired are subject to ground leases, which are accounted for as operating and capital leases, as applicable. The ground leases have varying ending dates, renewal options and rental rate escalations, with the latest lease extending to June 2053 . Future minimum rental payments to be made by the Company under these non-cancelable ground leases, excluding increases resulting from increases in the consumer price index, are as follows: October 1 to December 31, 2 017 2018 2019 2020 2021 Thereafter Total Ground Leases - Operating $ 562 $ 2,262 $ 2,295 $ 2,295 $ 2,262 $ 62,839 $ 72,515 Ground Leases - Capital — 1 — — — 329 330 Total $ 562 $ 2,263 $ 2,295 $ 2,295 $ 2,262 $ 63,168 $ 72,845

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company has elected to be taxed as a REIT, under Sections 856 through 860 of the Internal Revenue Code beginning with its taxable year ended December 31, 2004. To qualify as a REIT, the Company must meet certain organizational and operational requirements, including a requirement to distribute annually at least 90.0% of its ordinary taxable income to its shareholders. As a REIT, the Company generally will not be subject to U.S. federal income tax on taxable income that it distributes to its shareholders. The Operating Partnership is a limited partnership and therefore is generally not liable for federal corporate income taxes as income is reported in the tax returns of its partners. The Operating Partnership may, however, be subject to certain state and local taxes. The Operating Partnership has in the past established taxable REIT subsidiaries, or TRSs, to effect various taxable transactions. Typical transactions that could cause these TRSs to be subject to federal, state and local taxes would include, but are not limited to, gains on property sales and management fee income. The asset management agreement with KBS expired on March 31, 2017 and, consequently, the tax expense from the Operating Partnership’s TRS for the three and nine months ended September 30, 2017 was immaterial and the activity in the TRS will be immaterial going forward. Prior to 2017, income taxes, primarily related to TRSs, were accounted for under the asset and liability method. Deferred tax assets and liabilities were recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities recorded in accordance with GAAP and their respective tax basis and operating loss carryforwards. Deferred tax assets and liabilities were measured using enacted tax rates in effect for the year in which those temporary differences were expected to be recovered or settled. A valuation allowance was provided if the Company believed it was more likely than not that all or a portion of a deferred tax asset would not be realized. Any increase or decrease in a valuation allowance was included in the tax provision when such a change occurs. For the three and nine months ended September 30, 2017 the Company recorded $598 and $647 of income tax expense, respectively. The Company’s policy for interest and penalties, if any, on material uncertain tax positions recognized in the financial statements is to classify these as interest expense and operating expense, respectively. As of September 30, 2017 and December 31, 2016 , the Company did not incur any material interest or penalties.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2017
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information The following table represents supplemental cash flow disclosures for the nine months ended September 30, 2017 and 2016 : Nine Months Ended September 30, 2017 2016 Supplemental cash flow disclosures: Interest paid $ 62,024 $ 59,700 Income taxes paid 663 2,614 Proceeds from 1031 exchanges from sale of real estate 176,924 617,538 Use of funds from 1031 exchanges for acquisitions of real estate (176,924 ) (460,191 ) Non-cash activity: Fair value adjustment to noncontrolling interest in the Operating Partnership $ 1,191 $ 2,741 Debt assumed in acquisition of real estate 114,649 (45,958 ) Debt transferred in disposition of real estate (10,456 ) (101,432 ) Non-cash acquisition of consolidated VIE 24,930 — Dividend reinvestment plan proceeds 151 — Distribution of real estate assets from unconsolidated equity investment — 263,015 Treasury securities transferred in connection with defeasance of notes payable — (144,063 ) Transfer of defeased note payable — 124,605 Contribution of real estate assets as investment in unconsolidated equity investments — (182,168 ) Redemption of units of noncontrolling interest in the Operating Partnership for common shares (2,987 ) (4,159 ) Real estate acquired for units of noncontrolling interest in the Operating Partnership 68,898 — Redemption of Exchangeable Senior Notes for common shares 117,450 —

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In October 2017, the Company modified its 7 -Year Term Loan by increasing the loan from $175,000 to $400,000 . The modified 7-Year Term Loan has lower credit spreads and a swapped fixed rate of approximately 3.0% , which is a decrease of 34 basis points from the original agreement. Proceeds from the modification were used to pay down the 2015 Revolving Credit Facility. In October 2017, the Company entered into a new agreement to provide a mezzanine construction loan facility with a maximum balance of $250,000 to an industrial developer as a borrower. The facility has an initial term of five years, plus two one -year extension options and will earn interest ranging from 9.0% to 12.0% depending on the loan-to-value. The Company has approval rights for all new projects added to the facility and the facility provides the Company with the opportunity to purchase stabilized properties funded by the mezzanine facility. In October, the Company approved and funded $15,918 towards the mezzanine construction loan facility. In October 2017, the Company, along with several equity investment partners, also formed a European investment fund, which has total initial capital commitment of $310,262 ( €262,622 ) from all investors, of which the Company’s initial capital commitment is $61,654 ( €52,187 ). In October 2017, the Company declared a fourth quarter 2017 common dividend of $0.375 per share, payable on January 12, 2018 to shareholders of record as of December 29, 2017. In October 2017, the Company also declared a fourth quarter 2017 dividend on its 7.125% Series A Preferred Shares in the amount of $0.44531 per share, payable on December 29, 2017 to preferred shareholders of record as of the close of business on December 19, 2017. Subsequent to September 30, 2017 , the Company closed on the acquisition of three industrial properties which comprise an aggregate 587,680 rentable square feet, which are 100.0% occupied. The properties were acquired for an aggregate purchase price of approximately $106,360 in addition to the issuance of 1,294,359 OP Units, and related to the acquisitions, the Company assumed an aggregate of $66,458 of debt on two of the properties acquired. Subsequent to September 30, 2017 , the Company completed and placed into service its build-to-suit industrial property in Spartanburg, South Carolina, which comprises 432,100 square feet and is 100% leased. Subsequent to September 30, 2017 , the Company closed on the disposition of two office properties which comprised an aggregate 78,767 rentable square feet for gross proceeds of approximately $10,030 .

Significant Accounting Polici26

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Reclassifications	Reclassifications Certain prior year balances have been reclassified to conform with the current year presentation. These reclassifications had no effect on the previously reported net income.
Principles of Consolidation	Principles of Consolidation The Condensed Consolidated Financial Statements include the Company’s accounts and those of the Company’s subsidiaries which are wholly-owned or controlled by the Company, or entities which are VIEs in which the Company is the primary beneficiary. The primary beneficiary is the party that absorbs a majority of the VIE’s anticipated losses and/or a majority of the expected returns. The Company has evaluated its investments for potential classification as variable interests by evaluating the sufficiency of each entity’s equity investment at risk to absorb losses. Entities which the Company does not control and are considered VIEs, but where the Company is not the primary beneficiary, are accounted for under the equity method. All significant intercompany balances and transactions have been eliminated. The equity interests of other limited partners in the Company’s Operating Partnership are reflected as noncontrolling interests.
Real Estate Investments	Real Estate Investments Real Estate Acquisitions In January 2017, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2017-01, Amendments to Business Combinations, which clarifies the framework for determining whether an integrated set of assets and activities meets the definition of a business. The revised framework narrows the definition of a business, which is expected to result in fewer transactions being accounted for as business combinations. Acquisitions of integrated sets of assets and activities that do not meet the definition of a business are accounted for as asset acquisitions. Although the Company is not required to implement ASU 2017-01 until annual periods beginning after December 15, 2017, including interim periods within those periods, the Company early adopted the new standard in the first quarter of 2017. As a result, the Company evaluated its real estate acquisitions during the nine months ended September 30, 2017 under the new framework and determined the properties acquired did not meet the definition of a business, thus the transactions were accounted for as asset acquisitions. Refer to the "Recently Issued Accounting Pronouncements" section below for more information on the new guidance and refer to Note 4 for more information on the transactions during the nine months ended September 30, 2017 . The Company evaluates its acquisitions of real estate, including equity interests in entities that predominantly hold real estate assets, to determine if the acquired assets meet the definition of a business and need to be accounted for as a business combination, or alternatively, should be accounted for as an asset acquisition. An integrated set of assets and activities acquired does not meet the definition of a business if either (i) substantially all the fair value of the gross assets acquired is concentrated in either a single identifiable asset or a group of similar identifiable assets, or (ii) the asset and activities acquired do not contain at least an input and a substantive process that together significantly contribute to the ability to create outputs. The Company expects that its acquisitions of real estate will continue to not meet the revised definition of a business. Acquisitions of real estate that do not meet the definition of a business, including sale-leaseback transactions that have newly-originated leases and real estate investments under construction, or build-to-suit investments, are recorded as asset acquisitions. The accounting for asset acquisitions is similar to the accounting for business combinations, except that the acquisition consideration, including acquisition costs, is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. Based on this allocation methodology, asset acquisitions do not result in the recognition of goodwill or a bargain purchase. The Company incurs internal transaction costs, which are direct, incremental internal costs related to acquisitions, that are recorded within general and administrative expense. Additionally, for build-to-suit investments in which the Company may engage a developer to construct a property or provide funds to a tenant to develop a property, the Company capitalizes the funds provided to the developer/tenant and real estate taxes, if applicable, during the construction period. To determine the fair value of assets acquired and liabilities assumed in an acquisition, which generally include land, building, improvements, and intangibles, such as the value of above- and below-market leases and origination costs associated with the in-place leases at the acquisition date, the Company utilizes various estimates, processes and information to determine the as-if-vacant property value. Estimates of value are made using customary methods, including data from appraisals, comparable sales, and discounted cash flow analyses. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends, and market/economic conditions that may affect the property. The Company assesses the fair value of leases assumed at acquisition based upon estimated cash flow projections that utilize appropriate discount rates and available market information. Refer to the policy section "Intangible Assets and Liabilities" for more information on the Company’s accounting for intangibles. Depreciation is computed using the straight-line method over the shorter of the estimated useful life at acquisition of the capitalized item or 40 years for buildings, five to ten years for building equipment and fixtures, and the lesser of the useful life or the remaining lease term for tenant improvements and leasehold interests. Maintenance and repair expenditures are charged to expense as incurred. For transactions that qualify as business combinations, the Company recognizes the assets acquired and liabilities assumed at fair value, including the value of intangible assets and liabilities, and any excess or deficit of the consideration transferred relative to the fair value of the net assets acquired is recorded as goodwill or a bargain purchase gain, as appropriate. Acquisition costs of business combinations are expensed as incurred. Capital Improvements In leasing space, the Company may provide funding to the lessee through a tenant allowance. Certain improvements are capitalized when they are determined to increase the useful life of the building. During construction of qualifying projects, the Company capitalizes project management fees as permitted to be charged under the lease, if incremental and identifiable. In accounting for tenant allowances, the Company determines whether the allowance represents funding for the construction of leasehold improvements and evaluates the ownership of such improvements. If the Company is considered the owner of the leasehold improvements, the Company capitalizes the amount of the tenant allowance and depreciates it over the shorter of the useful life of the leasehold improvements or the lease term. If the tenant allowance represents a payment for a purpose other than funding leasehold improvements, or in the event the Company is not considered the owner of the improvements for accounting purposes, the allowance is considered to be a lease incentive and is recognized over the lease term as a reduction of rental revenue. Factors considered during this evaluation usually include (i) who holds legal title to the improvements, (ii) evidentiary requirements concerning the spending of the tenant allowance, and (iii) other controlling rights provided by the lease agreement (e.g. unilateral control of the tenant space during the build-out process). Determination of the accounting for a tenant allowance is made on a case-by-case basis, considering the facts and circumstances of the individual tenant lease. Impairments The Company reviews the recoverability of a property’s carrying value when circumstances indicate a possible impairment of the value of a property, such as an adverse change in future expected occupancy or a significant decrease in the market price of an asset. The review of recoverability is based on an estimate of the future undiscounted cash flows, excluding interest charges, expected to result from the property’s use and eventual disposition. These estimates consider factors such as changes in strategy resulting in an increased or decreased holding period, expected future operating income, market and other applicable trends and residual value, as well as the effects of leasing demand, competition and other factors. If management determines impairment exists due to the inability to recover the carrying value of a property, for properties to be held and used, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property and for assets held for sale, an impairment loss is recorded to the extent that the carrying value exceeds the fair value less estimated cost of disposal. These assessments are recorded as an impairment loss in the Condensed Consolidated Statements of Operations in the period the determination is made. The estimated fair value of the asset becomes its new cost basis. For a depreciable long-lived asset to be held and used, the new cost basis will be depreciated or amortized over the remaining useful life of that asset.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents.
Restricted Cash	Restricted Cash The Company had restricted cash of $19,183 and $12,904 at September 30, 2017 and December 31, 2016 , respectively, which primarily consisted of reserves for certain capital improvements, leasing, interest and real estate tax and insurance payments as required by certain mortgage note obligations.
Variable Interest Entities, Consolidated and Unconsolidated	Consolidated VIEs Operating Partnership The Operating Partnership is a consolidated VIE because the Company is its primary beneficiary due to its majority ownership and ability to exercise control over every aspect of the Operating Partnership’s operations. Gramercy Europe Asset Management (European Fund Manager) In connection with the Company’s December 2014 investment in the Gramercy European Property Fund, the Company acquired equity interests in the entity, hereinafter European Fund Manager, which provides investment and asset management services to the Gramercy European Property Fund. The Company determined that European Fund Manager is a VIE, as the equity holders of that entity do not have controlling financial interests and do not have the obligation to absorb losses. As Gramercy Europe Asset Management, through an investment advisory agreement with the VIE, controls the activities that most significantly affect the economic outcome of European Fund Manager, the Company concluded that it is the entity’s primary beneficiary and has consolidated the VIE. The Company receives net cash inflows from European Fund Manager in the form of management fees, and if the VIE’s cash inflows are not sufficient to cover its obligations, the Company may provide financial support for the VIE. Following the sale of the assets of the Gramercy European Property Fund in July 2017, European Fund Manager commenced liquidation and will be dissolved over the succeeding months. Related to the sale and forthcoming dissolution of European Fund Manager, the Company contributed $471 ( €400 ) to European Fund Manager during the three and nine months ended September 30, 2017. Proportion Foods In December 2015, the Company entered into a non-recourse financing arrangement with Big Proportion Austin LLC, or BIG, for a build-to-suit industrial property in Round Rock, Texas, or Proportion Foods. Concurrently, the Company entered into a forward purchase agreement with BIG, pursuant to which the Company agreed to acquire the property, which is 100.0% leased to Proportion Foods, upon substantial completion of the facility’s development. The Company determined that Proportion Foods was a VIE, as the equity holders of the entity did not have controlling financial interests and were not obligated to absorb losses. The Company controlled the activities that most significantly affected the economic outcome of Proportion Foods through its financing arrangement to fund the property’s development and its forward purchase agreement with BIG. As such, the Company concluded it was the entity’s primary beneficiary and consolidated the VIE. The construction of the facility on the property was completed in March 2017, at which time the Company acquired the property. Following the acquisition, the property was wholly-owned by the Company and was no longer a consolidated VIE. Unconsolidated VIEs Gramercy Europe Asset Management (European Fund Carry Co.) In connection with the Company’s December 2014 investment in the Gramercy European Property Fund, the Company acquired equity interests in the entity, hereinafter European Fund Carry Co., entitled to receive certain preferential distributions, if any, made from time-to-time by the Gramercy European Property Fund. The Company determined that European Fund Carry Co. is a VIE, as the equity holders of that entity do not have controlling financial interests and do not have the obligation to absorb losses in excess of capital committed. Decisions that most significantly affect the economic performance of European Fund Carry Co. are decided by a majority vote of that VIE’s shareholders. As such, the Company does not have a controlling financial interest in the VIE and accounts for it as an equity investment. Following the sale of the assets of the Gramercy European Property Fund in July 2017, European Fund Carry Co. commenced liquidation and will be dissolved over the succeeding months. Investment in Retained CDO Bonds The Company has retained non-investment grade subordinate bonds, preferred shares and ordinary shares of three collateralized debt obligations, or CDOs, together the Retained CDO Bonds. The Company does not control the activities that most significantly impact the Retained CDO Bonds’ economic performance and is not obligated to provide any financial support to them, thus the Retained CDO Bonds have been determined to be unconsolidated VIEs, in which the Company’s interest is recorded at fair value within other assets on the Condensed Consolidated Balance Sheets. The Retained CDO Bonds may provide the potential for the Company to receive continuing cash flows in the future, however, there is no guarantee that the Company will realize any proceeds from the Retained CDO Bonds or what the timing of the proceeds may be. The Company’s maximum exposure to loss is limited to its interest in the Retained CDO Bonds. In April 2017, one of the CDOs, in which the Company’s retained interest has no value, commenced liquidation. The Company will not receive any proceeds from the liquidation. Thus, as of September 30, 2017 , one of the Retained CDO Bonds is no longer considered a VIE of the Company.
Tenant and Other Receivables	Tenant and Other Receivables Tenant and other receivables are derived from rental revenue, tenant reimbursements, and management fees. Rental revenue is recorded on a straight-line basis over the initial term of the lease. Since many leases provide for rental increases at specified intervals, straight-line basis accounting requires the Company to record a receivable, and include in revenues, unbilled rent receivables that will only be received if the tenant makes all rent payments required through the expiration of the initial term of the lease. Tenant and other receivables also include receivables related to tenant reimbursements for common area maintenance expenses and certain other recoverable expenses that are recognized as revenue in the period in which the related expenses are incurred. Tenant and other receivables are recorded net of the allowances for doubtful accounts, which as of September 30, 2017 and December 31, 2016 were $691 and $57 , respectively. The Company continually reviews receivables related to rent, tenant reimbursements, and management fees, including incentive fees, and determines collectability by taking into consideration the tenant or asset management clients’ payment history, the financial condition of the tenant or asset management client, business conditions in the industry in which the tenant or asset management client operates and economic conditions in the area in which the property or asset management client is located. In the event that the collectability of a receivable is in doubt, the Company increases the allowance for doubtful accounts or records a direct write-off of the receivable, as appropriate. Management fees, including incentive management fees, are recognized as earned in accordance with the terms of the management agreements. The management agreements may contain provisions for fees related to dispositions, administration of the assets including fees related to accounting, valuation and legal services, and management of capital improvements or projects on the underlying assets.
Intangible Assets and Liabilities	Intangible Assets and Liabilities As discussed above in the policy section “Real Estate Acquisitions” the Company follows the acquisition method of accounting for its asset acquisitions and business combinations and thus allocates the purchase price of acquired properties to tangible and identifiable intangible assets acquired based on their respective fair values. Identifiable intangible assets include amounts allocated to acquired leases for above- and below- market lease rates and the value of in-place leases. Management also considers information obtained about each property as a result of its pre-acquisition due diligence. Above-market and below-market lease values for properties acquired are recorded based on the present value of the difference between the contractual amount to be paid pursuant to each in-place lease and management’s estimate of the fair market lease rate for each such in-place lease, measured over a period equal to the remaining non-cancelable term of the lease. The present value calculation utilizes a discount rate that reflects the risks associated with the leases acquired. The above-market and below-market lease values are amortized as a reduction of and increase to rental revenue, respectively, over the remaining non-cancelable terms of the respective leases. If a tenant terminates its lease prior to its contractual expiration and no future rental payments will be received, any unamortized balance of the market lease intangibles will be written off to rental revenue. The aggregate value of in-place leases represents the costs of leasing costs, other tenant related costs, and lost revenue that the Company did not have to incur by acquiring a property that is already occupied. Factors considered by management in its analysis of the in-place lease intangibles include an estimate of carrying costs during the expected lease-up period for each property taking into account current market conditions and costs to execute similar leases, including leasing commissions and other related expenses. In estimating carrying costs, management includes real estate taxes, insurance and other operating expenses and estimates of lost rentals at market rates during the anticipated lease-up period. The value of in-place leases is amortized to depreciation and amortization expense over the remaining non-cancelable term of the respective leases, but never over a term that exceeds the remaining depreciable life of the building. If a tenant terminates its lease prior to its contractual expiration and no future rental payments will be received, any unamortized balance of the in-place lease intangible will be written off to depreciation and amortization expense. Above-market and below-market ground rent intangibles are recorded for properties acquired in which the Company is the lessee pursuant to a ground lease assumed at acquisition. The above-market and below-market ground rent intangibles are valued similarly to above-market and below-market leases, except that, because the Company is the lessee as opposed to the lessor, the above-market and below-market ground lease values are amortized as a reduction of and increase to rent expense, respectively, over the remaining non-cancelable terms of the respective leases.
Revenue Recognition	Revenue Recognition Real Estate Investments Rental revenue from leases on real estate investments is recognized on a straight-line basis over the term of the lease, regardless of when payments are contractually due. The excess of rental revenue recognized over the amounts contractually due according to the underlying leases are included in other liabilities on the Condensed Consolidated Balance Sheets. For leases on properties that are under construction at the time of acquisition, the Company begins recognition of rental revenue upon completion of construction of the leased asset and delivery of the leased asset to the tenant. The Company’s lease agreements with tenants also generally contain provisions that require tenants to reimburse the Company for real estate taxes, insurance costs, common area maintenance costs, and other property-related expenses. Under lease arrangements in which the Company is the primary obligor for these expenses, such amounts are recognized as both revenues and operating expenses for the Company. Under lease arrangements in which the tenant pays these expenses directly, such amounts are not included in revenues or expenses. These reimbursement amounts are recognized in the period in which the related expenses are incurred. The Company recognizes sales of real estate properties only upon closing. Payments received from purchasers prior to closing are recorded as deposits. Profit on real estate sold is recognized using the full accrual method upon closing when the collectability of the sale price is reasonably assured and the Company is not obligated to perform significant activities after the sale. Profit may be deferred in whole or part until the sale meets the requirements of profit recognition on sale of real estate. Third-Party Management Fees The Company’s asset and property management agreements may contain provisions for fees related to administration of the assets including fees related to accounting, valuation and legal services, and management of capital improvements or projects on the underlying assets. The Company recognizes revenue for fees pursuant to its management agreements in the period in which they are earned. Deferred revenue from management fees received prior to the date earned is included in other liabilities on the Condensed Consolidated Balance Sheets. Certain of the Company’s asset management contracts and agreements with its unconsolidated equity investments include provisions that allow it to earn additional fees, generally described as incentive fees or promoted interests, based on the achievement of a targeted valuation or the achievement of a certain internal rate of return on the managed assets held by third parties or the equity investment. The Company recognizes incentive fees on its asset management contracts based upon the amount that would be due pursuant to the contract, if the contract were terminated at the reporting date. If the incentive fee is a fixed amount, only a proportionate share of revenue is recognized at the reporting date, with the remaining fees recognized on a straight-line basis over the measurement period. The Company recognizes promoted interest in the period in which it is determined to be appropriately earned pursuant to the terms of the specific agreement. The values of incentive management fees and promoted interest fees are periodically evaluated by management. For the three months ended September 30, 2017 , the Company did no t recognize any incentive fee revenue and for the nine months ended September 30, 2017 , the Company recognized incentive fees of $1,449 . For the three and nine months ended September 30, 2016 , the Company recognized incentive fees of $2,931 and $18,121 , respectively. Other Income Other income primarily consists of miscellaneous property related income, lease termination fees, income accretion on the Company’s Retained CDO Bonds, realized foreign currency exchange gains (losses), and interest income.
Foreign Currency	Foreign Currency Gramercy Europe Asset Management performs asset and property management services in Europe. The Company has unconsolidated equity investments in Europe and Asia and had two wholly-owned properties in Canada and one wholly-owned property in the United Kingdom until their dispositions in March 2017 and December 2016, respectively. The Company also has had borrowings outstanding in euros and British pounds sterling under the multicurrency portion of its revolving credit facility during 2017. Refer to Note 5 for more information on the Company’s foreign unconsolidated equity investments. Foreign Currency Translation During the periods presented, the Company has had interests in Europe and Canada for which the functional currencies are the euro, the British pound sterling, and the Canadian dollar, respectively. The Company performs the translation from these foreign currencies to the U.S. dollar for assets and liabilities using the exchange rates in effect at the balance sheet date and for revenue and expense accounts using a weighted average exchange rate during the period. The Company reports the gains and losses resulting from such translation as a component of other comprehensive income. For the three and nine months ended September 30, 2017 , the Company recorded net translation gains of $685 and $2,502 , respectively. For the three and nine months ended September 30, 2016 , the Company recorded net translation losses of $1,120 and $3,687 , respectively. Translation gains and losses are reclassified to other income within earnings when the Company has substantially exited from the foreign currency denominated asset or liability. Foreign Currency Transactions A transaction gain or loss realized upon settlement of a foreign currency transaction will be included in earnings for the period in which the transaction is settled. Foreign currency intercompany transactions that are scheduled for settlement are included in the determination of net income. Intercompany foreign currency transactions of a long-term nature that do not have a planned or foreseeable future settlement date, in which the entities to the transactions are consolidated or accounted for by the equity method in the Company’s financial statements, are not included in net income but are reported as a component of other comprehensive income.
Other Assets	Other Assets The Company includes prepaid expenses, capitalized software costs, contract intangible assets, deferred costs, goodwill, derivative assets, and Retained CDO Bonds in other assets.
Goodwill	Goodwill The Company recognized goodwill of $3,802 related to the acquisition of Gramercy Europe Limited, or Gramercy Europe Asset Management, which it adjusts each reporting period for the effect of foreign currency translation adjustments and tests for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that the asset might be impaired. The carrying value of goodwill at September 30, 2017 and December 31, 2016 was $3,244 and $2,988 , respectively. The Company did no t record any impairment on its goodwill during the three and nine months ended September 30, 2017 .
Retained CDO Bonds	Retained CDO Bonds The Retained CDO Bonds are non-investment grade subordinate bonds, preferred shares and ordinary shares of three CDOs. Management estimated the timing and amount of cash flows expected to be collected and recognized an investment in the Retained CDO Bonds equal to the net present value of these discounted cash flows. There is no guarantee that the Company will realize any proceeds from this investment, or what the timing will be for the expected remaining life of the Retained CDO Bonds. The Company considers these investments to be not of high credit quality and does not expect a full recovery of interest and principal. Therefore, the Company has suspended interest income accruals on these investments. The Company classifies the Retained CDO Bonds as available for sale. On a quarterly basis, the Company evaluates the Retained CDO Bonds to determine whether significant changes in estimated cash flows or unrealized losses on these investments, if any, reflect a decline in value which is other-than-temporary. If there is a decrease in estimated cash flows and the investment is in an unrealized loss position, the Company will record an other-than-temporary impairment, or OTTI, in the Condensed Consolidated Statements of Operations. To determine the component of the OTTI related to expected credit losses, the Company compares the amortized cost basis of the Retained CDO Bonds to the present value of the revised expected cash flows, discounted using the pre-impairment effective yield. Conversely, if the security is in an unrealized gain position and there is a decrease or significant increase in expected cash flows, the Company will prospectively adjust the yield using the effective yield method. Refer to Note 9 for further discussion regarding the fair value measurement of the Retained CDO Bonds.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash investments, debt investments and accounts receivable. The Company places its cash investments in excess of insured amounts with high quality financial institutions. Concentrations of credit risk also arise when a number of the Company’s tenants or asset management clients are engaged in similar business activities or are subject to similar economic risks or conditions that could cause their inability to meet contractual obligations to the Company. The Company regularly monitors its portfolio to assess potential concentrations of credit risk. Management believes the current credit risk portfolio is reasonably well diversified.
Segment Reporting	Segment Reporting ASC 280, Segment Reporting, establishes standards for the manner in which public enterprises report information about operating segments. In prior periods, the Company has viewed and presented its operations as two segments, Investments/Corporate and Asset Management. However, based upon the significant reduction in the Company’s third-party asset management operations following the expiration of the KBS management contract, as of March 31, 2017 , the Company views its operations as one segment, which consists of net leasing operations. The Company has no other reportable segments.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to customers in an amount reflecting the consideration it expects to receive in exchange for those goods or services. The guidance also requires enhanced disclosures related to the nature, amount, timing, and uncertainty of revenue that is recognized. In April 2016, the FASB issued ASU 2016-10, which amends the new revenue recognition guidance on identifying performance obligations. In February 2017, the FASB issued ASU 2017-05, which clarifies the scope of gains and losses from the derecognition of nonfinancial assets and provides guidance for the partial sales of nonfinancial assets in context of the new revenue standard. The new revenue recognition guidance is effective for the first interim period within annual reporting periods beginning after December 15, 2017, with early adoption permitted for the first interim period within annual reporting periods beginning after December 15, 2016. Companies may use either a full retrospective or a modified retrospective approach to adopt the new guidance. A substantial portion of the Company’s revenue consists of rental revenue from leasing arrangements, which is specifically excluded from the new revenue guidance, however the Company also generates revenue from operating expense reimbursements, management fees, incentive fees, and gains and impairments on disposals, which will be impacted by the new revenue standard. The Company does not believe the new revenue guidance will have a material impact on its recognition and disclosure of revenue, except as it pertains to revenue recognized for certain of its sales of unconsolidated equity investments. The Company currently expects to adopt the standard in the first quarter of 2018 using the modified retrospective approach. I n February 2016, the FASB issued ASU 2016-02, Leases, which 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. The update will be effective beginning in the first quarter of 2019 and early adoption is permitted. The new standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The Company’s accounting for leases in which it is a lessor, which represents most of its leasing arrangements, will be largely unchanged under ASU 2016-02, however the Company is a lessee in several operating and ground leases and the accounting for these arrangements is more significantly impacted by the new standard. Pursuant to the new guidance, lessees are required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. The Company is continuing to evaluate the impact of adopting the new leases standard on its Condensed Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting. The update serves to simplify the accounting for share-based payment award transactions, including income tax consequences, classification of awards as either equity or liabilities, and classification of awards on the statement of cash flows. The guidance in the ASU is effective for fiscal years beginning after December 15, 2016. The Company adopted the new guidance in the first quarter of 2017. The adoption of this guidance did not have a material impact on the Company’s Condensed Consolidated Financial Statements. In January 2017, the FASB issued ASU 2017-01, Amendments to Business Combinations, which amends the current guidance to clarify the definition of a business in order to assist entities in evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. The guidance is effective for annual and interim periods beginning after December 15, 2017, with early adoption permitted under certain circumstances. The amendments must be applied prospectively as of the beginning of the period of adoption. The Company elected to early adopt ASU 2017-01 in the first quarter of 2017, as described in the “Real Estate Acquisitions” section above. In January 2017, the FASB issued ASU 2017-04, Intangibles- Goodwill and Other, which simplifies the accounting for goodwill impairments. Under the new guidance, an impairment charge is recorded based on the excess of the reporting unit’s carrying amount over its fair value. The guidance is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 31, 2019 with early adoption permitted for impairment tests after January 1, 2017. The Company is currently evaluating the impact of this guidance on its Condensed Consolidated Financial Statements. In May 2017, the FASB issued ASU 2017-09, Compensation-Stock Compensation: Scope of Modification Accounting. The amendment provides guidance on determining which changes to the terms and conditions of share-based payment awards require an entity to apply modification accounting. The guidance is effective for annual and interim periods beginning after December 15, 2017, with early adoption permitted under certain circumstances. The Company is currently evaluating the impact of this guidance on its Condensed Consolidated Financial Statements. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities. The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. The transition guidance provides companies with the option of early adopting the new standard using a modified retrospective transition method in any interim period after issuance of the update, or alternatively requires adoption for fiscal years beginning after December 15, 2018. While the Company continues to assess all potential impacts of the standard, it currently expects adoption to have an immaterial impact on its consolidated financial statements.

Significant Accounting Polici27

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Schedule of Variable Interest Entities	The following is a summary of the Company’s involvement with VIEs as of September 30, 2017 : Company carrying value-assets Company carrying value-liabilities Face value of assets held by the VIEs Face value of liabilities issued by the VIEs Consolidated VIEs: Operating Partnership $ 6,541,338 $ 3,295,732 $ 6,541,338 $ 3,295,732 Gramercy Europe Asset Management (European Fund Manager) $ 1,736 $ 96 $ 1,736 $ 1,736 Unconsolidated VIEs: Gramercy Europe Asset Management (European Fund Carry Co.) $ 284 $ — $ 1,192 $ 57 Retained CDO Bonds $ 6,167 $ — $ 103,523 $ 80,629 The following is a summary of the Company’s involvement with VIEs as of December 31, 2016 : Company carrying value-assets Company carrying value-liabilities Face value of assets held by the VIEs Face value of liabilities issued by the VIEs Consolidated VIEs: Operating Partnership $ 5,603,527 $ 2,842,493 $ 5,603,527 $ 2,842,493 Proportion Foods $ 22,836 $ 3,041 $ 22,836 $ 23,514 Gramercy Europe Asset Management (European Fund Manager) $ 1,100 $ 47 $ 1,100 $ 1,742 Unconsolidated VIEs: Gramercy Europe Asset Management (European Fund Carry Co.) $ 8 $ — $ 31 $ — Retained CDO Bonds $ 11,906 $ — $ 391,990 $ 592,414
Schedule of Intangible Assets and Acquired Lease Obligations	Intangible assets and liabilities consist of the following: September 30, 2017 December 31, 2016 Intangible assets: In-place leases, net of accumulated amortization of $178,430 and $117,717 $ 571,839 $ 553,924 Above-market leases, net of accumulated amortization of $22,969 and $15,719 51,421 59,647 Below-market ground rent, net of accumulated amortization of $369 and $274 5,014 5,109 Amounts related to assets held for sale, net of accumulated amortization of $758 and $0 (2,503 ) — Total intangible assets $ 625,771 $ 618,680 Intangible liabilities: Below-market leases, net of accumulated amortization of $27,853 and $26,168 $ 171,251 $ 223,110 Above-market ground rent, net of accumulated amortization of $409 and $248 6,893 7,073 Amounts related to liabilities of assets held for sale, net of accumulated amortization of $698 and $0 (4,567 ) — Total intangible liabilities $ 173,577 $ 230,183
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table provides the weighted-average amortization period as of September 30, 2017 for intangible assets and liabilities and the projected amortization expense for the next five years. Weighted-Average Amortization Period (years) October 1 to December 31, 2017 2018 2019 2020 2021 In-place leases 9.3 $ 26,269 $ 100,181 $ 85,178 $ 71,067 $ 59,907 Total to be included in depreciation and amortization expense $ 26,269 $ 100,181 $ 85,178 $ 71,067 $ 59,907 Above-market lease assets 7.1 $ 2,688 $ 10,424 $ 9,425 $ 7,493 $ 6,196 Below-market lease liabilities 17.7 (3,166 ) (12,590 ) (12,240 ) (11,763 ) (10,641 ) Total to be included in rental revenue $ (478 ) $ (2,166 ) $ (2,815 ) $ (4,270 ) $ (4,445 ) Below-market ground rent 40.6 $ 32 $ 127 $ 127 $ 127 $ 127 Above-market ground rent 32.5 (53 ) (214 ) (214 ) (214 ) (214 ) Total to be included in property operating expense $ (21 ) $ (87 ) $ (87 ) $ (87 ) $ (87 )
Schedule of Retained Collateralized Debt Obligation Bonds	A summary of the Company’s Retained CDO Bonds as of September 30, 2017 is as follows: Number of Securities Face Value Amortized Cost Gross Unrealized Gain Other-than-temporary impairment Fair Value Weighted Average Expected Life (years) 6 $ 324,427 $ 4,670 $ 1,497 $ (4,890 ) $ 6,167 1.3
Other Than Temporary Impairment Credit Losses Recognized in Earnings	The following table summarizes the activity related to credit losses on the Retained CDO Bonds for the nine months ended September 30, 2017 and for the year ended December 31, 2016 : 2017 2016 Balance as of January 1, 2017 and 2016, respectively, of credit losses on Retained CDO Bonds for which a portion of an OTTI was recognized in other comprehensive income (loss) $ (491 ) $ 3,196 Additions to credit losses: On Retained CDO Bonds for which an OTTI was not previously recognized — — On Retained CDO Bonds for which an OTTI was previously recognized and a portion of an OTTI was recognized in other comprehensive income (loss) (4,890 ) — On Retained CDO Bonds for which an OTTI was previously recognized without any portion of OTTI recognized in other comprehensive income (loss) — — Reduction for credit losses: — — On Retained CDO Bonds for which no OTTI was recognized in other — — On Retained CDO Bonds sold during the period — — On Retained CDO Bonds charged off during the period — — For increases in cash flows expected to be collected that are recognized over the remaining life of the Retained CDO Bonds 523 (3,687 ) Balance as of September 30, 2017 and December 31, 2016, respectively, of credit of losses on Retained CDO Bonds for which a portion of an OTTI was recognized in other comprehensive income (loss) $ (4,858 ) $ (491 )

Dispositions, Assets Held for28

Dispositions, Assets Held for Sale, and Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Summary of Disposal Groups and Discontinued Operations	The following table summarizes the assets held for sale and liabilities related to the assets held for sale as of September 30, 2017 : Assets held for sale September 30, 2017 Real estate investments $ 14,507 Acquired lease assets, net 2,503 Other assets 282 Total assets $ 17,292 Liabilities related to assets held for sale Below-market lease liabilities, net 4,567 Other liabilities 347 Total liabilities $ 4,914 Net assets held for sale $ 12,378
Schedule Of Operating Results Of Assets Held For Sale Including In Discontinued Operations	The following operating results for the three and nine months ended September 30, 2017 and 2016 are included in discontinued operations for all periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Revenues $ 6 $ 262 $ 3 $ 6,259 Operating expenses — (58 ) 6 (2,294 ) General and administrative expense (30 ) (3 ) (85 ) (41 ) Interest expense — 148 — (807 ) Depreciation and amortization — (2 ) — (2 ) Gain on extinguishment of debt — — — 1,930 Income (loss) from discontinued operations $ (24 ) $ 347 $ (76 ) $ 5,045
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Schedule of Supplemental Cash Flow Activities	The following table represents supplemental cash flow disclosures for the nine months ended September 30, 2017 and 2016 : Nine Months Ended September 30, 2017 2016 Supplemental cash flow disclosures: Interest paid $ 62,024 $ 59,700 Income taxes paid 663 2,614 Proceeds from 1031 exchanges from sale of real estate 176,924 617,538 Use of funds from 1031 exchanges for acquisitions of real estate (176,924 ) (460,191 ) Non-cash activity: Fair value adjustment to noncontrolling interest in the Operating Partnership $ 1,191 $ 2,741 Debt assumed in acquisition of real estate 114,649 (45,958 ) Debt transferred in disposition of real estate (10,456 ) (101,432 ) Non-cash acquisition of consolidated VIE 24,930 — Dividend reinvestment plan proceeds 151 — Distribution of real estate assets from unconsolidated equity investment — 263,015 Treasury securities transferred in connection with defeasance of notes payable — (144,063 ) Transfer of defeased note payable — 124,605 Contribution of real estate assets as investment in unconsolidated equity investments — (182,168 ) Redemption of units of noncontrolling interest in the Operating Partnership for common shares (2,987 ) (4,159 ) Real estate acquired for units of noncontrolling interest in the Operating Partnership 68,898 — Redemption of Exchangeable Senior Notes for common shares 117,450 —
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Schedule of Supplemental Cash Flow Activities	The table below presents additional relevant information pertaining to results of discontinued operations for the nine months ended September 30, 2017 and 2016 , including depreciation, amortization, capital expenditures, and significant operating and investing non-cash items: Nine Months Ended September 30, 2017 2016 Amortization expense $ — $ 2 Significant operating non-cash items — (9,647 ) Total $ — $ (9,645 )

Real Estate Investments (Tables

Real Estate Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Real Estate [Abstract]
Schedule of Business Acquisitions, by Acquisition	The aggregate changes recorded from the preliminary purchase price allocations to the finalized purchase price allocations, are shown in the table below and are reflected in earnings for the nine months ended September 30, 2017 : Preliminary Allocations recorded Finalized Allocations recorded Real Estate Assets Intangible Assets Intangible Liabilities Real Estate Assets Intangible Assets Intangible Liabilities Decrease to Rental Revenue Increase to Depreciation and Amortization Expense $ 513,424 $ 61,178 $ 11,093 $ 513,087 $ 60,627 $ 10,205 $ 27 $ 16

Unconsolidated Equity Investm30

Unconsolidated Equity Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Equity Method Investments	As of September 30, 2017 and December 31, 2016 , the Company owned properties through unconsolidated equity investments and had investment interests in these unconsolidated entities as follows: As of September 30, 2017 As of December 31, 2016 Investment Ownership % Voting Interest % Partner Investment in Unconsolidated Equity Investment 1 No. of Properties Investment in Unconsolidated Equity Investment 1 No. of Properties Gramercy European Property Fund 2 14.2 % 14.2 % Various $ 1,109 — $ 50,367 26 Goodman Europe JV 3 — % — % Gramercy European Property Fund — — 3,491 8 Strategic Office Partners 25.0 % 25.0 % TPG Real Estate 35,760 11 15,872 6 Goodman UK JV 80.0 % 50.0 % Goodman Group 30,884 1 25,309 2 CBRE Strategic Partners Asia 5.07 % 5.07 % Various 2,772 1 4,145 2 Philips JV 25.0 % 25.0 % Various — 1 — 1 Morristown JV 50.0 % 50.0 % 21 South Street 2,638 1 2,623 1 Total $ 73,163 15 $ 101,807 46 1. The amounts presented include a basis difference of $1,930 , net of accumulated amortization, for the Goodman UK JV as of September 30, 2017 . The amounts presented include basis differences of $2,286 and $3,941 , net of accumulated amortization, for the Goodman Europe JV and Goodman UK JV, respectively, as of December 31, 2016 . 2. The Gramercy European Property Fund sold 100.0% of its assets to a third party in July 2017. Pursuant to the sale agreement, as of September 30, 2017 , $1,109 of the sale proceeds are being held in escrow, thus this remaining distribution held in escrow represents the total value of the Company’s investment in the entity following the transaction. The amounts presented include European Fund Carry Co., which has a carrying value of $284 and $8 for the Company’s 25.0% interest as of September 30, 2017 and December 31, 2016 , respectively. 3. In the table above the Company’s 94.9% indirect interest in the Goodman Europe JV held through its 14.2% interest in the Gramercy European Property Fund is included in the amount shown for the Gramercy European Property Fund and the Company’s 5.1% direct interest in the Goodman Europe JV is presented separately as the amount shown for the Goodman Europe JV. In July 2017, the Company sold its 5.1% direct interest in the Goodman Europe JV and the assets of the Goodman Europe JV were sold to a third party as part of the aforementioned sale of the assets of Gramercy European Property Fund
Summary Investment Holdings	The following is a summary of the Company’s unconsolidated equity investments for the nine months ended September 30, 2017 : Unconsolidated Equity Investments Balance at January 1, 2017 $ 101,807 Contributions to unconsolidated equity investments 20,775 Equity in net income of unconsolidated equity investments, including adjustments for basis differences 48,884 Other comprehensive income of unconsolidated equity investments 7,286 Distributions from unconsolidated equity investments (96,434 ) Reclassification of unrealized gain on non-derivative net investment hedge into earnings 1,851 Sale of unconsolidated equity investment interests (9,644 ) Reclassification of accumulated foreign currency translation adjustments due to disposal (1,362 ) Balance at September 30, 2017 $ 73,163
Schedule of Combined Balance Sheet for the Company's Joint Venture	The following are the balance sheets for the Company’s unconsolidated equity investments at September 30, 2017 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia Other 2 Assets: Real estate assets, net 3 $ — $ — $ — $ 259,949 $ 18,678 $ 78,202 $ 48,784 Other assets — 12,084 12,084 57,319 20,314 11,214 4,217 Total assets $ — $ 12,084 $ 12,084 $ 317,268 $ 38,992 $ 89,416 $ 53,001 Liabilities and members’ equity: Mortgage notes payable $ — $ — $ — $ 159,140 $ — $ — $ 38,973 Other liabilities — 5,126 5,126 13,008 194 14,677 3,407 Total liabilities — 5,126 5,126 172,148 194 14,677 42,380 Company’s equity — 825 825 35,760 30,884 2,772 2,922 Other members’ equity — 6,133 6,133 109,360 7,914 71,967 7,699 Liabilities and members’ equity $ — $ 12,084 $ 12,084 $ 317,268 $ 38,992 $ 89,416 $ 53,001 1. In July 2017, the Gramercy European Property Fund sold 100.0% of its assets, including its 94.9% interest in the Goodman Europe JV. The remaining net assets as of September 30, 2017 primarily represent a portion of the sale proceeds being held in escrow, pursuant to the sale agreement. 2. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The amounts that pertain to European Fund Carry Co. include assets of $1,192 , liabilities of $57 , the Company’s 25.0% share of equity totaling $284 , and other members’ equity of $851 . 3. Includes basis adjustments that were recorded by the Company to adjust the unconsolidated equity investments to fair value upon closing of the Merger. The following are the balance sheets for the Company’s unconsolidated equity investments at December 31, 2016 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund 2 Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia Other 3 Assets: Real estate assets, net 4 $ 285,087 $ 347,069 $ 632,156 $ 149,484 $ 25,128 $ 87,852 $ 49,580 Other assets 86,273 63,523 149,796 42,323 6,650 12,247 3,020 Total assets $ 371,360 $ 410,592 $ 781,952 $ 191,807 $ 31,778 $ 100,099 $ 52,600 Liabilities and members' equity: Mortgage notes payable $ 174,269 $ 215,980 $ 390,249 $ 121,894 $ — $ — $ 39,730 Other liabilities 7,778 19,940 27,718 4,347 934 14,383 3,259 Total liabilities 182,047 235,920 417,967 126,241 934 14,383 42,989 Company's equity 12,734 41,116 53,850 15,872 25,309 4,145 2,631 Other members' equity 176,579 133,556 310,135 49,694 5,535 81,571 6,980 Liabilities and members' equity $ 371,360 $ 410,592 $ 781,952 $ 191,807 $ 31,778 $ 100,099 $ 52,600 1. As of December 31, 2016 , the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. In the table above, the Company’s equity interest in the Goodman Europe JV includes both its direct 5.1% interest as well as its indirect interest that was held through its 14.2% interest in the Gramercy European Property Fund, and the Company’s equity interest in the Gramercy European Property Fund represents its interest in all of the properties owned by the Gramercy European Property Fund except for the properties in the Goodman Europe JV. 2. Excludes the Gramercy European Property Fund’s 94.9% interest in the Goodman Europe JV. 3. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. 4. Includes basis adjustments that were recorded by the Company to adjust the unconsolidated equity investments to fair value upon closing of the Merger.
Schedule of Long-term Debt	The following is a summary of the secured financing arrangements within the Company’s unconsolidated equity investments as of September 30, 2017 : Outstanding Balance 2 Property Unconsolidated Equity Investment Economic Ownership Interest Rate 1 Maturity Date September 30, 2017 December 31, 2016 Strategic Office Partners portfolio 3 Strategic Office Partners 25.0% 4.23% 10/7/2019 $ 162,080 $ 125,000 Durrholz, Germany Gramercy European Property Fund 14.2% 1.52% 3/31/2020 — 12,289 Venray, Germany Gramercy European Property Fund 14.2% 3.32% 12/2/2020 — 13,015 Lille, France Gramercy European Property Fund 14.2% 3.13% 12/17/2020 — 27,081 Carlisle, United Kingdom Gramercy European Property Fund 14.2% 3.32% 2/19/2021 — 10,443 Oud Beijerland, Netherlands Gramercy European Property Fund 14.2% 2.09% 12/30/2022 — 8,077 Zaandam, Netherlands Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 11,647 Kerkrade, Netherlands Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 9,622 Friedrichspark, Germany Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 8,694 Fredersdorf, Germany Gramercy European Property Fund 14.2% 2.08% 12/30/2022 — 11,247 Breda, Netherlands Gramercy European Property Fund 14.2% 1.90% 12/30/2022 — 9,948 Juechen, Germany Gramercy European Property Fund 14.2% 1.89% 12/30/2022 — 18,852 Piaseczno, Poland Gramercy European Property Fund 14.2% 1.98% 12/30/2022 — 8,141 Strykow, Poland Gramercy European Property Fund 14.2% 1.98% 12/30/2022 — 19,167 Uden, Netherlands Gramercy European Property Fund 14.2% 1.98% 12/30/2022 — 8,913 Rotterdam, Netherlands Gramercy European Property Fund 14.2% 1.89% 12/30/2022 — 7,633 Frechen, Germany Gramercy European Property Fund 14.2% 1.49% 12/30/2022 — 6,043 Meerane, Germany Gramercy European Property Fund 14.2% 1.35% 12/30/2022 — 10,138 Amsterdam, Netherlands Gramercy European Property Fund 14.2% 1.59% 12/30/2022 — 3,093 Tiel, Netherlands Gramercy European Property Fund 14.2% 1.59% 12/30/2022 — 9,174 Netherlands portfolio 4 Gramercy European Property Fund 14.2% 3.02% 6/28/2023 — 13,409 Kutno, Poland Gramercy European Property Fund 14.2% 1.91% 7/21/2023 — 5,890 European Facility 1 5 Goodman Europe JV 18.6% 0.90% 11/16/2023 — 31,551 European Facility 2 5 Goodman Europe JV 18.6% 1.75% 11/16/2023 — 106,917 Worksop, United Kingdom Gramercy European Property Fund 14.2% 3.94% 10/20/2026 — 10,551 Somerset, NJ Philips JV 25.0% 6.90% 9/11/2035 38,973 39,730 Total mortgage notes payable $ 201,053 $ 546,265 Net deferred financing costs and net debt premium (discount) (2,940 ) 5,608 Total mortgage notes payable, net $ 198,113 $ 551,873 1. Represents the current effective rate as of September 30, 2017 , including the swapped interest rate for mortgage notes that have interest rate swaps. The current interest rate is not adjusted to include the amortization of fair market value premiums or discounts. 2. Mortgage notes are presented at 100.0% of the amount held by the unconsolidated equity investment. 3. There are nine properties under this mortgage note. 4. There are five properties under this mortgage note. 5. There were eight properties under this mortgage facility. In addition, this represents the Company’s economic ownership in the Goodman Europe JV, which included both its 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund.
Schedule of Combined Income Statement for the Company's Joint Venture	The following are the statements of operations for the Company’s unconsolidated equity investments for the three months ended September 30, 2017 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia 2 Other 3 Revenues $ 303 $ 593 $ 896 $ 8,451 $ 25 $ (7,766 ) $ 36,224 Operating expenses 33 (1,288 ) (1,255 ) 2,828 82 295 170 Interest expense 29 152 181 2,432 — — 690 Depreciation and amortization 120 237 357 3,969 204 — 333 Total expenses 182 (899 ) (717 ) 9,229 286 295 1,193 Net income (loss) from operations 121 1,492 1,613 (778 ) (261 ) (8,061 ) 35,031 Loss on derivatives — (22 ) (22 ) (144 ) — — — Loss on extinguishment of debt — — — (937 ) — — — Net gain on disposals — 230,392 230,392 9,923 7,871 — — Provision for taxes (38 ) (68 ) (106 ) — 30 — — Net income (loss) $ 83 $ 231,794 $ 231,877 $ 8,064 $ 7,640 $ (8,061 ) $ 35,031 Company's share in net income (loss) $ 4 $ 32,927 $ 32,931 $ 2,125 $ 6,112 $ (411 ) $ 8,777 Adjustments for REIT basis — — — — (2,159 ) — — Gain (loss) from disposal of Company's interest 6,458 (5,103 ) 1,355 — — — — Company's equity in net income (loss) within continuing operations $ 6,462 $ 27,824 $ 34,286 $ 2,125 $ 3,953 $ (411 ) $ 8,777 1. Prior to the sale of the assets of the Gramercy European Property Fund and the Company’s sale of its interest in the Goodman Europe JV to a third party in July 2017, the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the three months ended September 30, 2017 , the Company’s equity in net income (loss) of the entities is based on these ownership interest percentages. 2. The Company received a distribution of $812 related to the sale of a property in September by CBRE Strategic Partners Asia, however, due to the 3-month reporting lag, the Company’s financial results reflect information through June 30, 2017, which includes the sold asset. 3. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The amounts that pertain to European Fund Carry Co. include revenues of $35,127 , expenses of $62 , and the Company’s 25.0% share in net income of $8,766 . The following are statements of operations for the Company’s unconsolidated equity investments for the nine months ended September 30, 2017 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV CBRE Strategic Partners Asia 2 Other 3 Revenues $ 10,581 $ 22,190 $ 32,771 $ 21,151 $ 613 $ (9,981 ) $ 38,432 Operating expenses 1,900 4,465 6,365 6,618 609 996 444 Interest expense 1,315 3,424 4,739 5,997 — — 2,031 Depreciation and amortization 4,165 10,032 14,197 9,324 840 — 999 Total expenses 7,380 17,921 25,301 21,939 1,449 996 3,474 Net income (loss) from operations 3,201 4,269 7,470 (788 ) (836 ) (10,977 ) 34,958 Gain (loss) on derivatives — 2,248 2,248 (906 ) — — — Loss on extinguishment of debt — — — (937 ) — — — Net gain on disposals — 230,392 230,392 9,923 7,871 — — Provision for taxes (70 ) (346 ) (416 ) — 2 — — Net income (loss) $ 3,131 $ 236,563 $ 239,694 $ 7,292 $ 7,037 $ (10,977 ) $ 34,958 Company’s share in net income (loss) $ 159 $ 33,812 $ 33,971 $ 2,074 $ 5,629 $ (561 ) $ 8,777 Adjustments for REIT basis (73 ) — (73 ) — (2,288 ) — — Gain (loss) from disposal of Company's interest 6,458 (5,103 ) 1,355 — — — — Company’s equity in net income (loss) within continuing operations $ 6,544 $ 28,709 $ 35,253 $ 2,074 $ 3,341 $ (561 ) $ 8,777 1. Prior to the sale of the assets of the Gramercy European Property Fund and the Company’s sale of its interest in the Goodman Europe JV to a third party in July 2017, the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the nine months ended September 30, 2017 , the Company’s equity in net income (loss) of the entities is based on these ownership interest percentages. 2. The Company received a distribution of $812 related to the sale of a property in September by CBRE Strategic Partners Asia, however, due to the 3-month reporting lag, the Company’s financial results reflect information through June 30, 2017, which includes the sold asset. 3. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The amounts that pertain to European Fund Carry Co. include revenues of $35,127 , expenses of $77 , and the Company’s 25.0% share in net income of $8,763 . The following are the statements of operations for the Company’s unconsolidated equity investments for the three months ended September 30, 2016 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV Duke JV CBRE Strategic Partners Asia Other 2 Revenues $ 6,195 $ 7,329 $ 13,524 $ 1,291 $ 557 $ 417 $ (11,557 ) $ 1,080 Operating expenses 676 1,619 2,295 280 225 191 341 129 Acquisition expenses — 2,141 2,141 664 — — — — Interest expense 653 1,138 1,791 410 — — — 698 Depreciation and amortization 3,276 2,800 6,076 898 339 — — 333 Total expenses 4,605 7,698 12,303 2,252 564 191 341 1,160 Net income (loss) from operations 1,590 (369 ) 1,221 (961 ) (7 ) 226 (11,898 ) (80 ) Loss on derivatives — (1,124 ) (1,124 ) (129 ) — — — — Net gain on disposals — — — — — 28,170 — — Provision for taxes — (284 ) (284 ) — — — — — Net income (loss) $ 1,590 $ (1,777 ) $ (187 ) $ (1,090 ) $ (7 ) $ 28,396 $ (11,898 ) $ (80 ) Company’s share in net income (loss) $ 322 $ (252 ) $ 70 $ (273 ) $ (6 ) $ 20,749 $ (605 ) $ (4 ) Adjustments for REIT basis 11 — 11 — (183 ) (20,897 ) — — Company’s equity in net income (loss) within continuing operations $ 333 $ (252 ) $ 81 $ (273 ) $ (189 ) $ (148 ) $ (605 ) $ (4 ) 1. As of and for the three months ended September 30, 2016 , the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the three months ended September 30, 2016 , the Company’s equity in net income (loss) from the entities is based on these ownership interest percentages during the period. 2. Includes the Philips JV, the Morristown JV, and European Fund Carry Co. The following are the statements of operations for the Company’s unconsolidated equity investments for the nine months ended September 30, 2016 : Gramercy European Property Fund 1 Goodman Europe JV Gramercy European Property Fund Total Strategic Office Partners Goodman UK JV Duke JV CBRE Strategic Partners Asia Other 2 Revenues $ 18,389 $ 18,270 $ 36,659 $ 1,291 $ 5,477 $ 19,812 $ (11,315 ) $ 3,245 Operating expenses 2,372 3,188 5,560 280 698 5,309 1,208 342 Acquisition expenses 4,960 4,678 9,638 664 — — — 27 Interest expense 2,519 3,032 5,551 410 — 602 — 2,131 Depreciation and amortization 7,907 7,632 15,539 898 1,461 7,154 — 998 Total expenses 17,758 18,530 36,288 2,252 2,159 13,065 1,208 3,498 Net income (loss) from operations 631 (260 ) 371 (961 ) 3,318 6,747 (12,523 ) (253 ) Loss on derivatives — (6,428 ) (6,428 ) (129 ) — — — — Loss on extinguishment of debt — — — — — (7,962 ) — — Net gain on disposals — — — — — 66,705 — — Provision for taxes — (876 ) (876 ) — — — — — Net income (loss) $ 631 $ (7,564 ) $ (6,933 ) $ (1,090 ) $ 3,318 $ 65,490 $ (12,523 ) $ (253 ) Company’s share in net income (loss) $ (444 ) $ (1,386 ) $ (1,830 ) $ (273 ) $ 2,655 $ 50,424 $ (641 ) $ — Adjustments for REIT basis 455 — 455 — (461 ) (54,390 ) — — Company’s equity in net income (loss) within continuing operations $ 11 $ (1,386 ) $ (1,375 ) $ (273 ) $ 2,194 $ (3,966 ) $ (641 ) $ — 1. On May 31, 2016, the Gramercy European Property Fund acquired a 20.0% interest in the Goodman Europe JV and on June 30, 2016, the Gramercy European Property Fund acquired 74.9% of the Company’s 80.0% % interest in the Goodman Europe JV. As of September 30, 2016 , the Company had a 5.1% direct interest in the Goodman Europe JV as well as an indirect interest in the remaining 94.9% interest that was held through the Company’s 14.2% interest in the Gramercy European Property Fund. For the nine months ended September 30, 2016 , the Company’s equity in net income (loss) from the entities is based on these ownership percentages during the period. 2. Includes the Philips JV, the Morristown JV, and European Fund Carry Co.

Debt Obligations (Tables)

Debt Obligations (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Mortgage Notes Payable	The following is a summary of the Company’s secured financing arrangements as of September 30, 2017 and December 31, 2016 : Property Interest Rate 1 Maturity Date Outstanding Balance September 30, 2017 December 31, 2016 Dallas, TX 2 3.05% 3/1/2018 $ 9,372 $ 9,540 Jacksonville, FL 2 3.05% 3/1/2018 6,732 6,852 Cincinnati, KY 2 3.29% 3/1/2018 6,512 6,628 Minneapolis, MN 2 3.05% 3/1/2018 5,896 6,001 Phoenix, AZ 2 3.05% 3/1/2018 4,048 4,120 Ames, IA 5.05% 5/1/2018 16,069 16,436 Columbus, OH 4.01% 5/31/2018 19,006 19,708 Greenwood, IN 3.59% 6/15/2018 7,302 7,436 Greenfield, IN 3.63% 6/15/2018 5,902 6,010 Logistics Portfolio - Pool 3 3 3.96% 8/1/2018 43,300 43,300 Philadelphia, PA 4.99% 1/1/2019 12,041 12,328 Columbus, OH 3.94% 1/31/2019 5,768 5,908 Bridgeview, IL 3.90% 5/1/2019 5,883 6,014 Spartanburg, SC 3.20% 6/1/2019 732 1,025 Charleston, SC 3.11% 8/1/2019 591 986 Lawrence, IN 5.02% 1/1/2020 20,224 20,703 Charlotte, NC 3.28% 1/1/2020 1,711 2,217 Hawthorne, CA 3.52% 8/1/2020 17,327 17,638 Charleston, SC 3.32% 10/1/2020 820 1,001 Charleston, SC 2.97% 10/1/2020 806 984 Charleston, SC 3.37% 10/1/2020 806 984 Charlotte, NC 3.38% 10/1/2020 700 853 Des Plaines, IL 5.54% 10/31/2020 2,405 2,463 Waco, TX 4.75% 12/19/2020 14,964 15,187 Deerfield, IL 3.71% 1/1/2021 10,538 10,804 Winston-Salem, NC 3.41% 6/1/2021 3,569 4,199 Winston-Salem, NC 3.42% 7/1/2021 1,184 1,388 Logistics Portfolio - Pool 1 3 4.27% 1/1/2022 38,355 39,002 CCC Portfolio 3 4.24% 10/6/2022 22,933 23,280 Logistics Portfolio - Pool 4 3 4.36% 12/5/2022 79,500 79,500 KIK USA Portfolio 3 4.31% 7/6/2023 7,230 7,450 Yuma, AZ 5.27% 12/6/2023 11,909 12,058 Allentown, PA 5.16% 1/6/2024 22,790 23,078 Spartanburg, SC 3.72% 2/1/2024 5,821 6,360 Maple Grove, MN 3.88% 5/6/2024 16,468 — Curtis Bay, MD 4.31% 7/1/2024 13,500 — Rialto, CA 3.91% 8/1/2024 54,940 — Durham, NC 4.02% 9/6/2024 3,648 — Houston, TX 3.68% 9/1/2024 26,000 — Charleston, SC 3.80% 2/1/2025 6,169 6,658 Hackettstown, NJ 5.49% 3/6/2026 9,488 9,550 Hutchins, TX 5.41% 6/1/2029 21,883 22,764 Logistics Portfolio - Pool 2 3 4.48% 1/1/2041 35,711 36,279 Buford, GA 4.67% 7/1/2017 — 15,512 Woodcliff Lake, NJ 3.04% 9/15/2017 — 35,366 KIK Canada Portfolio 3 3.57% 5/5/2019 — 7,914 Total mortgage notes payable $ 600,553 $ 555,484 Net deferred financing costs and net debt premium 6,345 3,158 Total mortgage notes payable, net $ 606,898 $ 558,642 1. Represents the interest rate as of September 30, 2017 or date of extinguishment if the mortgage note was extinguished during the period, that was recorded for financial reporting purposes, which reflects the effect of interest rate swaps and amortization of financing costs and fair market value premiums or discounts. 2. These five mortgage notes are cross-collateralized. 3. There are two properties under the Logistics Portfolio - Pool 3 mortgage, three properties under the Logistics Portfolio - Pool 1 mortgage, five properties under the CCC Portfolio mortgage, six properties under the Logistics Portfolio - Pool 4 mortgage, three properties under the KIK USA Portfolio mortgage, five properties under the Logistics Portfolio - Pool 2 mortgage, and two properties under the KIK Canada Portfolio mortgage.
Schedule of Line of Credit Facilities	The terms of the Company’s unsecured debt obligations and outstanding balances as of September 30, 2017 and December 31, 2016 are set forth in the table below: Stated Interest Rate Effective Interest Rate 1 Maturity Date Outstanding Balance September 30, 2017 December 31, 2016 2015 Revolving Credit Facility - U.S. dollar tranche 2.20 % 2.20 % 1/8/2020 $ 595,000 $ — 2015 Revolving Credit Facility - Multicurrency tranche 1.20 % 1.20 % 1/8/2020 $ 20,097 $ 65,837 3-Year Term Loan 2.35 % 2.33 % 1/8/2019 300,000 300,000 5-Year Term Loan 2.35 % 2.70 % 1/8/2021 750,000 750,000 7-Year Term Loan 2.76 % 3.34 % 1/9/2023 175,000 175,000 2015 Senior Unsecured Notes 4.97 % 5.07 % 12/17/2024 150,000 150,000 2016 Senior Unsecured Notes 3.89 % 4.00 % 12/15/2022 150,000 150,000 2016 Senior Unsecured Notes 4.26 % 4.38 % 12/15/2025 100,000 100,000 2016 Senior Unsecured Notes 4.32 % 4.43 % 12/15/2026 100,000 100,000 Exchangeable Senior Notes 2 3.75 % 6.36 % 9/15/2017 — 115,000 Total unsecured debt 2,340,097 1,905,837 Net deferred financing costs and net debt discount (3,316 ) (9,704 ) Total unsecured debt, net $ 2,336,781 $ 1,896,133 1. Represents the rate at which interest expense is recorded for financial reporting purposes as of September 30, 2017 , which reflects the effect of interest rate swaps and amortization of financing costs and fair market value premiums or discounts. 2. During September 2017, the Exchangeable Senior Notes were exchanged for the Company’s common shares. Thus, they have no outstanding balance as of September 30, 2017
Schedule of Maturities of Long-term Debt	Combined aggregate principal maturities of the Company’s unsecured debt obligations, non-recourse mortgages, and Exchangeable Senior Notes, in addition to associated interest payments, as of September 30, 2017 are as follows: October 1 to December 31, 2017 2018 2019 2020 2021 Thereafter Above market interest Total 2015 Revolving Credit Facility $ — $ — $ — $ 615,097 $ — $ — $ — $ 615,097 Term Loans — — 300,000 — 750,000 175,000 — 1,225,000 Mortgage Notes Payable 1 4,073 171,988 35,003 61,803 18,153 309,533 — 600,553 Senior Unsecured Notes — — — — — 500,000 — 500,000 Interest Payments 2 28,780 94,453 86,650 69,801 44,158 43,378 3,029 370,249 Total $ 32,853 $ 266,441 $ 421,653 $ 746,701 $ 812,311 $ 1,027,911 $ 3,029 $ 3,310,899 1. Mortgage note payments reflect accelerated repayment dates, when applicable, pursuant to related the loan agreement. 2. Interest payments do not reflect the effect of interest rate swaps.

Leasing Agreements (Tables)

Leasing Agreements (Tables)	9 Months Ended
	Sep. 30, 2017
Leases, Operating [Abstract]
Schedule of Future Minimum Rental Payments for Lease Agreements	Future minimum rental revenues under non-cancelable leases excluding reimbursements for operating expenses as of September 30, 2017 are as follows: October 1 to December 31, 2017 2018 2019 2020 2021 Thereafter Total minimum lease rental income Operating Leases $ 112,429 $ 450,096 $ 424,686 $ 396,516 $ 362,870 $ 1,973,979 $ 3,720,576

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Carrying Value and Fair Value of Financial Instruments	The following table presents the carrying value in the financial statements and approximate fair value of assets and liabilities measured on a recurring and nonrecurring basis at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value Financial assets: Interest rate swaps $ 8,243 $ 8,243 $ 3,769 $ 3,769 Retained CDO Bonds 6,167 6,167 11,906 11,906 Investment in CBRE Strategic Partners Asia 2,772 2,772 4,145 4,145 Real estate investments 1 14,561 14,561 2,413 2,413 Financial liabilities: Interest rate swaps $ 391 $ 391 $ 700 $ 700 Long-term debt 2015 Revolving Credit Facility 2 615,097 612,120 65,837 65,897 3-Year Term Loan 2 300,000 299,180 300,000 300,213 5-Year Term Loan 2 750,000 744,851 750,000 750,959 7-Year Term Loan 2 175,000 176,516 175,000 172,850 Mortgage notes payable 2 606,898 618,097 558,642 567,705 Senior Unsecured Notes 2 496,684 508,547 496,464 498,650 Exchangeable Senior Notes 2 — — 108,832 115,625 1. Amounts as of September 30, 2017 and December 31, 2016 represent four and one real estate investments, respectively, that were impaired during the nine months ended September 30, 2017 and the year ended December 31, 2016 , respectively, and were owned as of the end of the respective reporting periods. 2. Long-term debt instruments are classified as Level III due to the significance of unobservable inputs which are based upon management assumptions.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis and on a non-recurring basis are categorized in the table below based upon the lowest level of significant input to the valuations. At September 30, 2017 Total Level I Level II Level III Financial Assets: Retained CDO Bonds $ 6,167 $ — $ — $ 6,167 Real estate investments 14,561 — — 14,561 Investment in CBRE Strategic Partners Asia 2,772 — — 2,772 Interest rate swaps 8,243 — — 8,243 $ 31,743 $ — $ — $ 31,743 Financial Liabilities: Interest rate swaps $ (391 ) $ — $ — $ (391 ) $ (391 ) $ — $ — $ (391 ) At December 31, 2016 Total Level I Level II Level III Financial Assets: Retained CDO Bonds $ 11,906 $ — $ — $ 11,906 Real estate investments 2,413 — — 2,413 Investment in CBRE Strategic Partners Asia 4,145 — — 4,145 Interest rate swaps 3,769 — — 3,769 $ 22,233 $ — $ — $ 22,233 Financial Liabilities: Interest rate swaps $ (700 ) $ — $ — $ (700 ) $ (700 ) $ — $ — $ (700 )
Fair Value, Assets and Liabilities Measured on Recurring Basis, Valuation Techniques	Quantitative information regarding the valuation techniques and the range of significant unobservable Level III inputs used to determine fair value measurements on a recurring basis as of September 30, 2017 are as follows: Financial Asset (Liability) Fair Value Valuation Technique Unobservable Inputs Range Non-investment grade, subordinate CDO bonds $ 6,167 Discounted cash flows Discount rate 16.5% Interest rate swaps 1 7,852 Hypothetical derivative method Credit borrowing spread 135 to 205 basis points Investment in CBRE Strategic Partners Asia 2,772 Discounted cash flows Discount rate 20.0% 1. Fair value includes interest rate swap liabilities with an aggregate value of $(391) .
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following rollforward table reconciles the beginning and ending balances of financial assets (liabilities) measured at fair value on a recurring basis using Level III inputs as of September 30, 2017 : Retained CDO Bonds Investment in CBRE Strategic Partners Asia Interest Rate Swaps Total Financial Assets (Liabilities) - Level III Balance at January 1, 2017 $ 11,906 $ 4,145 $ 3,069 $ 19,120 Amortization of discounts or premiums 1,353 — — 1,353 Adjustments to fair value: Ineffective portion of change in derivative instruments — — 138 138 Unrealized gain on derivatives — — 4,645 4,645 Unrealized loss in other comprehensive income from fair value adjustment (2,202 ) — — (2,202 ) Other-than-temporary impairments (4,890 ) — — (4,890 ) Total loss on fair value adjustments — (561 ) — (561 ) Distributions from financial assets — (812 ) — (812 ) Balance at September 30, 2017 $ 6,167 $ 2,772 $ 7,852 $ 16,791
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following rollforward table reconciles the beginning and ending balances of financial assets (liabilities) measured at fair value on a recurring basis using Level III inputs as of September 30, 2017 : Retained CDO Bonds Investment in CBRE Strategic Partners Asia Interest Rate Swaps Total Financial Assets (Liabilities) - Level III Balance at January 1, 2017 $ 11,906 $ 4,145 $ 3,069 $ 19,120 Amortization of discounts or premiums 1,353 — — 1,353 Adjustments to fair value: Ineffective portion of change in derivative instruments — — 138 138 Unrealized gain on derivatives — — 4,645 4,645 Unrealized loss in other comprehensive income from fair value adjustment (2,202 ) — — (2,202 ) Other-than-temporary impairments (4,890 ) — — (4,890 ) Total loss on fair value adjustments — (561 ) — (561 ) Distributions from financial assets — (812 ) — (812 ) Balance at September 30, 2017 $ 6,167 $ 2,772 $ 7,852 $ 16,791

Derivatives and Non-Derivativ34

Derivatives and Non-Derivative Hedging Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The Company’s derivatives and hedging instruments as of September 30, 2017 are as follows: Benchmark Rate Notional Value Strike Rate Effective Date Expiration Date Fair Value Interest Rate Swap - Waco 1 mo. USD-LIBOR-BBA 14,964 USD 4.55% 12/19/2013 12/19/2020 $ (313 ) Interest Rate Swap - Atrium I 1 mo. USD-LIBOR-BBA 19,006 USD 1.78% 8/16/2011 5/31/2018 (48 ) Interest Rate Swap - Easton III 1 mo. USD-LIBOR-BBA 5,768 USD 1.95% 8/16/2011 1/31/2019 (31 ) Interest Rate Swap - 3-Year Term Loan 1 mo. USD-LIBOR-BBA 100,000 USD 1.22% 12/19/2016 12/17/2018 375 Interest Rate Swap - 3-Year Term Loan 1 mo. USD-LIBOR-BBA 100,000 USD 1.23% 12/19/2016 12/17/2018 370 Interest Rate Swap - 3-Year Term Loan 1 mo. USD-LIBOR-BBA 100,000 USD 1.24% 12/19/2016 12/17/2018 357 Interest Rate Swap - 5-Year Term Loan 1 mo. USD-LIBOR-BBA 750,000 USD 1.60% 12/17/2015 12/17/2020 4,352 Interest Rate Swap - 7-Year Term Loan 1 mo. USD-LIBOR-BBA 175,000 USD 1.82% 12/17/2015 1/9/2023 739 Forward Starting Swap 1 3 mo. USD-LIBOR-BBA 250,000 USD 2.23% 12/20/2017 12/20/2027 2,051 Net Investment Hedge in GBP-denominated investments USD-GBP exchange rate 15,000 GBP N/A 7/15/2016 N/A — Total hedging instruments $ 7,852 1. During the three months ended September 30, 2017, the Company entered into one forward starting swap to hedge the risk of changes in the interest-related cash outflows associated with potential new long-term debt arrangements. The forward starting swap has a mandatory early termination date of March 20, 2018.

Shareholders' Equity (Deficit35

Shareholders' Equity (Deficit) of the Company (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Dividends Declared	During the nine months ended September 30, 2017 , the Company’s common dividends are as follows: Quarter Ended Record Date Payment Date Common dividend per share March 31, 2017 3/31/2017 4/14/2017 $ 0.375 June 30, 2017 6/30/2017 7/14/2017 $ 0.375 September 30, 2017 9/30/2017 10/16/2017 $ 0.375
Schedule of Calculation of Numerator and Denominator in Earnings Per Share	Earnings per share for the three and nine months ended September 30, 2017 and 2016 are computed as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Numerator – Income (loss): Net income (loss) from continuing operations $ 45,607 $ (3,411 ) $ 43,520 $ 14,461 Net income (loss) from discontinued operations (24 ) 347 (76 ) 5,045 Net income (loss) before net gain on disposals 45,583 (3,064 ) 43,444 19,506 Net gain on disposals 4,879 2,336 24,258 2,336 Gain on sale of European unconsolidated equity investment interests held with a related party — — — 5,341 Net Income (loss) 50,462 (728 ) 67,702 27,183 Less: Net income attributable to noncontrolling interest (333 ) (221 ) (374 ) (152 ) Less: Nonforfeitable dividends allocated to participating shareholders (191 ) (196 ) (766 ) (596 ) Less: Preferred share dividends (1,559 ) (1,559 ) (4,676 ) (4,676 ) Net income (loss) available to common shares outstanding - basic $ 48,379 $ (2,704 ) $ 61,886 $ 21,759 Plus: Interest expense on Exchangeable Senior Notes 1,462 — — — Net income (loss) available to common shares outstanding - diluted $ 49,841 $ (2,704 ) $ 61,886 $ 21,759 Denominator – Weighted average shares 1 : Basic weighted average shares outstanding 152,619,352 140,257,503 147,399,457 141,180,822 Effect of dilutive securities: Unvested non-participating share based payment awards 15,052 — 12,709 137,803 Options 21,015 — 18,716 13,802 Outside interests in the Operating Partnership — — — 399,771 Exchangeable Senior Notes 4,851,794 — — 655,511 Diluted weighted average shares outstanding 157,507,213 140,257,503 147,430,882 142,387,709 1. Share and per share amounts have been adjusted for the 1-for-3 reverse share split completed on December 30, 2016. The Operating Partnership's earnings per unit for the three and nine months ended September 30, 2017 and 2016 are computed as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Numerator – Income (loss): Net income (loss) from continuing operations $ 45,607 $ (3,411 ) $ 43,520 $ 14,461 Net income (loss) from discontinued operations (24 ) 347 (76 ) 5,045 Net income (loss) before net gain on disposals 45,583 (3,064 ) 43,444 19,506 Net gain on disposals 4,879 2,336 24,258 2,336 Gain on sale of European unconsolidated equity investment interests held with a related party — — — 5,341 Net Income (loss) 50,462 (728 ) 67,702 27,183 Less: Net (gain) loss attributable to noncontrolling interest in other partnerships 97 (229 ) 114 (90 ) Less: Nonforfeitable dividends allocated to participating unitholders (191 ) (196 ) (766 ) (596 ) Less: Preferred unit distributions (1,559 ) (1,559 ) (4,676 ) (4,676 ) Net income (loss) available to common units outstanding - basic $ 48,809 $ (2,712 ) $ 62,374 $ 21,821 Plus: Interest expense on Exchangeable Senior Notes 1,462 — — — Net income (loss) available to common units outstanding - diluted $ 50,271 $ (2,712 ) $ 62,374 $ 21,821 Denominator – Weighted average units 1 : Basic weighted average units outstanding 153,971,961 140,596,612 148,248,795 141,580,593 Effect of dilutive securities: Unvested non-participating share based payment awards 15,052 — 12,709 137,803 Options 21,015 — 18,716 13,802 Exchangeable Senior Notes 4,851,794 — — 655,511 Diluted weighted average units outstanding 158,859,822 140,596,612 148,280,220 142,387,709 1. Unit and per unit amounts have been adjusted for the 1-for-3 reverse unit split completed on December 30, 2016.
Schedule of Accumulated Other Comprehensive Income (Loss)	Accumulated other comprehensive income (loss) as of September 30, 2017 and December 31, 2016 is comprised of the following: September 30, 2017 December 31, 2016 Net unrealized gain (loss) on derivative securities $ 4,205 $ (440 ) Net unrealized gain on debt instruments 1,497 3,699 Foreign currency translation adjustments: Net gain on non-derivative net investment hedges 1 288 4,516 Other foreign currency translation adjustments (5,826 ) (13,045 ) Reclassification of swap gain into interest expense 1,954 1,142 Total accumulated other comprehensive income (loss) $ 2,118 $ (4,128 ) 1. The foreign currency translation adjustment associated with the Company’s non-derivative net investment hedge related to its European investments is included in other comprehensive income (loss). The balance reflects write-offs of $1,851 and $652 on the Company’s non-derivative net investment hedge during the nine months ended September 30, 2017 and the year ended December 31, 2016 , respectively.

Partners' Capital of the Oper36

Partners' Capital of the Operating Partnership (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share	Earnings per share for the three and nine months ended September 30, 2017 and 2016 are computed as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Numerator – Income (loss): Net income (loss) from continuing operations $ 45,607 $ (3,411 ) $ 43,520 $ 14,461 Net income (loss) from discontinued operations (24 ) 347 (76 ) 5,045 Net income (loss) before net gain on disposals 45,583 (3,064 ) 43,444 19,506 Net gain on disposals 4,879 2,336 24,258 2,336 Gain on sale of European unconsolidated equity investment interests held with a related party — — — 5,341 Net Income (loss) 50,462 (728 ) 67,702 27,183 Less: Net income attributable to noncontrolling interest (333 ) (221 ) (374 ) (152 ) Less: Nonforfeitable dividends allocated to participating shareholders (191 ) (196 ) (766 ) (596 ) Less: Preferred share dividends (1,559 ) (1,559 ) (4,676 ) (4,676 ) Net income (loss) available to common shares outstanding - basic $ 48,379 $ (2,704 ) $ 61,886 $ 21,759 Plus: Interest expense on Exchangeable Senior Notes 1,462 — — — Net income (loss) available to common shares outstanding - diluted $ 49,841 $ (2,704 ) $ 61,886 $ 21,759 Denominator – Weighted average shares 1 : Basic weighted average shares outstanding 152,619,352 140,257,503 147,399,457 141,180,822 Effect of dilutive securities: Unvested non-participating share based payment awards 15,052 — 12,709 137,803 Options 21,015 — 18,716 13,802 Outside interests in the Operating Partnership — — — 399,771 Exchangeable Senior Notes 4,851,794 — — 655,511 Diluted weighted average shares outstanding 157,507,213 140,257,503 147,430,882 142,387,709 1. Share and per share amounts have been adjusted for the 1-for-3 reverse share split completed on December 30, 2016. The Operating Partnership's earnings per unit for the three and nine months ended September 30, 2017 and 2016 are computed as follows: Three Months Ended September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Numerator – Income (loss): Net income (loss) from continuing operations $ 45,607 $ (3,411 ) $ 43,520 $ 14,461 Net income (loss) from discontinued operations (24 ) 347 (76 ) 5,045 Net income (loss) before net gain on disposals 45,583 (3,064 ) 43,444 19,506 Net gain on disposals 4,879 2,336 24,258 2,336 Gain on sale of European unconsolidated equity investment interests held with a related party — — — 5,341 Net Income (loss) 50,462 (728 ) 67,702 27,183 Less: Net (gain) loss attributable to noncontrolling interest in other partnerships 97 (229 ) 114 (90 ) Less: Nonforfeitable dividends allocated to participating unitholders (191 ) (196 ) (766 ) (596 ) Less: Preferred unit distributions (1,559 ) (1,559 ) (4,676 ) (4,676 ) Net income (loss) available to common units outstanding - basic $ 48,809 $ (2,712 ) $ 62,374 $ 21,821 Plus: Interest expense on Exchangeable Senior Notes 1,462 — — — Net income (loss) available to common units outstanding - diluted $ 50,271 $ (2,712 ) $ 62,374 $ 21,821 Denominator – Weighted average units 1 : Basic weighted average units outstanding 153,971,961 140,596,612 148,248,795 141,580,593 Effect of dilutive securities: Unvested non-participating share based payment awards 15,052 — 12,709 137,803 Options 21,015 — 18,716 13,802 Exchangeable Senior Notes 4,851,794 — — 655,511 Diluted weighted average units outstanding 158,859,822 140,596,612 148,280,220 142,387,709 1. Unit and per unit amounts have been adjusted for the 1-for-3 reverse unit split completed on December 30, 2016.

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	9 Months Ended
	Sep. 30, 2017
Noncontrolling Interest [Abstract]
Noncontrolling Interest in the Operating Partnership	Below is the rollforward of the activity relating to the noncontrolling interests in the Operating Partnership as of September 30, 2017 : Noncontrolling Interest Balance at January 1, 2017 $ 8,643 Issuance of noncontrolling interests in the Operating Partnership 68,898 Redemption of noncontrolling interests in the Operating Partnership (2,987 ) Net income attribution 488 Fair value adjustments 1,191 Dividends (1,094 ) Balance at September 30, 2017 $ 75,139

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments	Future minimum rental payments to be made by the Company under these non-cancelable ground leases, excluding increases resulting from increases in the consumer price index, are as follows: October 1 to December 31, 2 017 2018 2019 2020 2021 Thereafter Total Ground Leases - Operating $ 562 $ 2,262 $ 2,295 $ 2,295 $ 2,262 $ 62,839 $ 72,515 Ground Leases - Capital — 1 — — — 329 330 Total $ 562 $ 2,263 $ 2,295 $ 2,295 $ 2,262 $ 63,168 $ 72,845

Supplemental Cash Flow Inform39

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2017
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flow Activities	The following table represents supplemental cash flow disclosures for the nine months ended September 30, 2017 and 2016 : Nine Months Ended September 30, 2017 2016 Supplemental cash flow disclosures: Interest paid $ 62,024 $ 59,700 Income taxes paid 663 2,614 Proceeds from 1031 exchanges from sale of real estate 176,924 617,538 Use of funds from 1031 exchanges for acquisitions of real estate (176,924 ) (460,191 ) Non-cash activity: Fair value adjustment to noncontrolling interest in the Operating Partnership $ 1,191 $ 2,741 Debt assumed in acquisition of real estate 114,649 (45,958 ) Debt transferred in disposition of real estate (10,456 ) (101,432 ) Non-cash acquisition of consolidated VIE 24,930 — Dividend reinvestment plan proceeds 151 — Distribution of real estate assets from unconsolidated equity investment — 263,015 Treasury securities transferred in connection with defeasance of notes payable — (144,063 ) Transfer of defeased note payable — 124,605 Contribution of real estate assets as investment in unconsolidated equity investments — (182,168 ) Redemption of units of noncontrolling interest in the Operating Partnership for common shares (2,987 ) (4,159 ) Real estate acquired for units of noncontrolling interest in the Operating Partnership 68,898 — Redemption of Exchangeable Senior Notes for common shares 117,450 —

Business and Organization (Narr

Business and Organization (Narrative) (Details) € in Thousands, $ in Thousands	Jun. 30, 2016USD ($)	Jun. 30, 2016EUR (€)	Jul. 31, 2017USD ($)Property	Jul. 31, 2017EUR (€)Property	Sep. 30, 2017USD ($)ft²buildingProperty	Mar. 31, 2017Property	Sep. 30, 2016Property	Sep. 30, 2017USD ($)ft²buildingProperty	Sep. 30, 2017USD ($)ft²buildingProperty	Sep. 30, 2017USD ($)ft²buildingPropertyland_parcel	Sep. 30, 2017USD ($)ft²buildingProperty	Sep. 30, 2016USD ($)Property	Dec. 31, 2016USD ($)Property
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Properties | Property					15			15	15	15	15		46
Proceeds from sale of investment								$ 87,229				$ 84,588
Number of Acquisitions						21			74	2
Square Feet | ft²											18,361,835
Purchase Price								1,321,886
Acquisition of land								6,840
Buildings					$ 4,845,246			4,845,246	$ 4,845,246	$ 4,845,246	$ 4,845,246		$ 4,053,125
Number of real estate properties sold | Property							10					20
Proceeds from sale of property held-for-sale								$ 256,828
Wholly Owned Properties [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Properties | building					367			367	367	367	367
Area of real estate property | ft²					81,046,993			81,046,993	81,046,993	81,046,993	81,046,993
Occupancy rate					97.40%			97.40%	97.40%	97.40%	97.40%
Unconsolidated Properties [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Properties | Property					14			14	14	14	14
GPT Operating Partnership LP [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage by noncontrolling owners					1.92%			1.92%	1.92%	1.92%	1.92%
Proceeds from sale of investment								$ 87,229				$ 84,588
Buildings					$ 4,845,246			4,845,246	$ 4,845,246	$ 4,845,246	$ 4,845,246		$ 4,053,125
Gramercy Asset Management [Member] | Commercial Lease Properties [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Commercial real estate assets					1,622,000			1,622,000	1,622,000	1,622,000	1,622,000
Europe [Member] | Gramercy Asset Management [Member] | Commercial Lease Properties [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Commercial real estate assets					$ 1,305,000			$ 1,305,000	$ 1,305,000	$ 1,305,000	$ 1,305,000
CBRE Strategic Partners Asia [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Properties | Property					1			1	1	1	1		2
Ownership %					5.07%			5.07%	5.07%	5.07%	5.07%
Number of real estate properties sold | Property									1
Gramercy European Property Fund [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Properties | Property			30	30	0			0	0	0	0		26
Ownership %					14.20%			14.20%	14.20%	14.20%	14.20%		14.20%
Ownership interest sold			100.00%	100.00%
Proceeds from sale of investment			$ 101,930	€ 89,366
Proceeds from sale, promoted interest distribution			$ 8,515	€ 7,448
Goodman Europe JV [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Properties | Property			8	8	0			0	0	0	0		8
Ownership %			5.10%	5.10%	0.00%		80.00%	0.00%	0.00%	0.00%	0.00%	80.00%	5.10%
Proceeds from sale of investment	$ 148,884	€ 134,336
Consolidated VIE [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Purchase Price								$ 29,605
Land [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Purchase Price								2,400
Build-to-suit Property [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Acquisitions | Property									1
Purchase Price								63,244
Industrial Facility [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of Acquisitions | land_parcel										2
Acquisition of land								2,800
Buildings					$ 49,077			$ 49,077	$ 49,077	$ 49,077	$ 49,077
Disposed by Sale [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of real estate properties sold | Property					8				25
Area of real estate properties sold | ft²											2,358,928
Disposed by Sale [Member] | Offices [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of real estate properties sold | Property									2

Significant Accounting Polici41

Significant Accounting Policies (Narrative) (Details) € in Thousands	Jun. 29, 2017segment	Sep. 30, 2017USD ($)Propertyentity	Sep. 30, 2017EUR (€)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Propertysegmententity	Sep. 30, 2017EUR (€)segment	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)Propertyentity	Dec. 31, 2015USD ($)entity
Accounting Policies [Line Items]
Restricted cash		$ 19,183,000			$ 19,183,000			$ 12,904,000
Number of consolidated VIEs | entity		2			2			3
Number of unconsolidated variable interest entities | entity		3			3			4	4
Contributions to unconsolidated equity investments					$ 20,775,000
Allowance for doubtful accounts receivable		$ 691,000			691,000			$ 57,000
Amortization of intangible assets		25,525,000		$ 29,670,000	73,864,000		$ 86,845,000
Amortization of off market lease unfavorable and off market lease favorable		(872,000)		4,578,000	4,505,000		10,388,000
Amortization of ground rent intangible assets and liabilities		3,252,000		4,810,000	8,771,000		14,922,000
Incentive fee recognized		$ 0		2,931,000	$ 1,449,000		18,121,000
Number of Properties | Property		15			15			46
Foreign currency translation gain (loss)		$ 685,000		(1,120,000)	$ 2,502,000		(3,687,000)
Foreign currency transaction gain, realized		7,000		185,000	64,000		104,000
Impairment of goodwill				0	$ 0		0
Number of operating segments | segment	2				1	1
Available-for-sale Securities [Member]
Accounting Policies [Line Items]
Retained collateralized debt obligations (CDOs) bonds, other-than-temporary impairment		$ 0		$ 0	$ 4,890,000		$ 0
Bank Of America [Member] | Sales Revenue, Goods, Net [Member] | Customer Concentration Risk [Member]
Accounting Policies [Line Items]
Concentration risk, percentage				13.70%			13.30%
Bank Of America [Member] | Sales Revenue, Goods, Net [Member] | Customer Concentration Risk [Member] | Below-market lease liabilities [Member]
Accounting Policies [Line Items]
Concentration risk, percentage				7.00%			6.00%
Proportion Foods [Member]
Accounting Policies [Line Items]
Percentage of area leased property		100.00%			100.00%
Gramercy Europe Asset Management - European Fund Manager [Member]
Accounting Policies [Line Items]
Contributions to unconsolidated equity investments		$ 471,000	€ 400		$ 471,000	€ 400
Gramercy Europe Asset [Member] | Canada [Member]
Accounting Policies [Line Items]
Number of Properties | Property		2			2
Gramercy Europe Asset [Member] | United Kingdom [Member]
Accounting Policies [Line Items]
Number of Properties | Property		1			1
Restatement Adjustment [Member]
Accounting Policies [Line Items]
Investment income reclassified				$ 544,000			$ 1,490,000
Gramercy Europe Limited [Member]
Accounting Policies [Line Items]
Goodwill		$ 3,244,000			$ 3,244,000			$ 2,988,000	$ 3,802,000
Ground Lease [Member]
Accounting Policies [Line Items]
Reduction of other property operating expense for ground rent intangible assets and liabilities		$ (23,000)		$ 8,000
Amortization of ground rent intangible assets and liabilities					$ (66,000)		$ 25,000
Building [Member]
Accounting Policies [Line Items]
Property, plant and equipment, useful life					40 years	40 years
Building Equipment and Fixtures [Member] | Minimum [Member]
Accounting Policies [Line Items]
Property, plant and equipment, useful life					5 years	5 years
Building Equipment and Fixtures [Member] | Maximum [Member]
Accounting Policies [Line Items]
Property, plant and equipment, useful life					10 years	10 years

Significant Accounting Polici42

Significant Accounting Policies (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Retained CDO Bonds [Member]
Unconsolidated VIEs:
Company carrying value-assets, unconsolidated	$ 6,167	$ 11,906
Company carrying value - liabilities, unconsolidated	0	0
Face value of assets held by the VIEs, unconsolidated	103,523	391,990
Face value of liabilities issued by the VIEs, unconsolidated	80,629	592,414
Operating Partnership [Member]
Consolidated VIEs:
Company carrying value-assets, consolidated	6,541,338	5,603,527
Company carrying value - liabilities, consolidated	3,295,732	2,842,493
Face value of assets held by the VIEs, consolidated	6,541,338	5,603,527
Face value of liabilities issued by the VIEs, consolidated	3,295,732	2,842,493
Proportion Foods [Member]
Consolidated VIEs:
Company carrying value-assets, consolidated		22,836
Company carrying value - liabilities, consolidated		3,041
Face value of assets held by the VIEs, consolidated		22,836
Face value of liabilities issued by the VIEs, consolidated		23,514
Gramercy Europe Asset Management - European Fund Manager [Member]
Consolidated VIEs:
Company carrying value-assets, consolidated	1,736	1,100
Company carrying value - liabilities, consolidated	96	47
Face value of assets held by the VIEs, consolidated	1,736	1,100
Face value of liabilities issued by the VIEs, consolidated	1,736	1,742
Gramercy Europe Asset Management - European Fund Carry Co [Member]
Unconsolidated VIEs:
Company carrying value-assets, unconsolidated	284	8
Company carrying value - liabilities, unconsolidated	0	0
Face value of assets held by the VIEs, unconsolidated	1,192	31
Face value of liabilities issued by the VIEs, unconsolidated	$ 57	$ 0

Significant Accounting Polici43

Significant Accounting Policies (Schedule of Intangible Assets and Acquired Lease Obligations) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Intangible assets:
Total intangible assets	$ 625,771	$ 618,680
Finite-lived intangible assets, accumulated amortization	201,010	133,710
Intangible liabilities:
Total intangible liabilities	173,577	230,183
In-place leases [Member]
Intangible assets:
Total intangible assets	571,839	553,924
Finite-lived intangible assets, accumulated amortization	178,430	117,717
Above-market leases [Member]
Intangible assets:
Total intangible assets	51,421	59,647
Finite-lived intangible assets, accumulated amortization	22,969	15,719
Below-market ground rent [Member]
Intangible assets:
Total intangible assets	5,014	5,109
Finite-lived intangible assets, accumulated amortization	369	274
Below-market leases [Member]
Intangible liabilities:
Total intangible liabilities	171,251	223,110
Finite-lived intangible liabilities, accumulated amortization	27,853	26,168
Above-market ground rent [Member]
Intangible liabilities:
Total intangible liabilities	6,893	7,073
Finite-lived intangible liabilities, accumulated amortization	409	248
Assets Held-for-sale [Member]
Intangible assets:
Amounts related to assets held for sale, net of accumulated amortization of $758 and $0	(2,503)	0
Finite-lived intangible assets, accumulated amortization	758	0
Intangible liabilities:
Amounts related to liabilities of assets held for sale, net of accumulated amortization of $698 and $0	(4,567)	0
Finite-lived intangible liabilities, accumulated amortization	$ 698	$ 0

Significant Accounting Polici44

Significant Accounting Policies (Schedule of Finite-Lived Intangible Assets, Future Amortization Expense) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Depreciation and Amortization Expense [Member]
Finite-Lived Intangible Assets
October 1 to December 31, 2017	$ 26,269
2,018	100,181
2,019	85,178
2,020	71,067
2,021	59,907
Rental Revenue [Member]
Finite-Lived Intangible Assets, Amortization Expense And Below Market Leases, Amortized Income
October 1 to December 31, 2017	(478)
2,018	(2,166)
2,019	(2,815)
2,020	(4,270)
2,021	(4,445)
Property Operating Expense [Member]
Finite-Lived Intangible Assets, Amortization Expense And Below Market Leases, Amortized Income
October 1 to December 31, 2017	(21)
2,018	(87)
2,019	(87)
2,020	(87)
2,021	$ (87)
In-place leases [Member]
Schedule of Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Weighted-Average Amortization Period (years)	9 years 3 months 19 days
In-place leases [Member] | Depreciation and Amortization Expense [Member]
Finite-Lived Intangible Assets
October 1 to December 31, 2017	$ 26,269
2,018	100,181
2,019	85,178
2,020	71,067
2,021	$ 59,907
Above-market lease assets [Member]
Schedule of Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Weighted-Average Amortization Period (years)	7 years 1 month 6 days
Above-market lease assets [Member] | Rental Revenue [Member]
Finite-Lived Intangible Assets
October 1 to December 31, 2017	$ 2,688
2,018	10,424
2,019	9,425
2,020	7,493
2,021	$ 6,196
Below-market lease liabilities [Member]
Schedule of Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Weighted-Average Amortization Period (years)	17 years 8 months 12 days
Below-market lease liabilities [Member] | Rental Revenue [Member]
Below Market Lease
October 1 to December 31, 2017	$ (3,166)
2,018	(12,590)
2,019	(12,240)
2,020	(11,763)
2,021	$ (10,641)
Below-market ground rent [Member]
Schedule of Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Weighted-Average Amortization Period (years)	40 years 7 months 6 days
Below-market ground rent [Member] | Property Operating Expense [Member]
Finite-Lived Intangible Assets
October 1 to December 31, 2017	$ 32
2,018	127
2,019	127
2,020	127
2,021	$ 127
Above-market ground rent [Member]
Schedule of Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Weighted-Average Amortization Period (years)	32 years 6 months
Above-market ground rent [Member] | Property Operating Expense [Member]
Finite-Lived Intangible Assets, Amortization Expense And Below Market Leases, Amortized Income
October 1 to December 31, 2017	$ (53)
2,018	(214)
2,019	(214)
2,020	(214)
2,021	$ (214)

Significant Accounting Polici45

Significant Accounting Policies (Schedule of Retained Collateralized Debt Obligation Bonds) (Details) - Available-for-sale Securities [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)security	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)security	Sep. 30, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | security	6		6
Face Value	$ 324,427,000		$ 324,427,000
Amortized Cost	4,670,000		4,670,000
Gross Unrealized Gain			1,497,000
Other-than-temporary impairment	0	$ 0	(4,890,000)	$ 0
Fair Value	$ 6,167,000		$ 6,167,000
Weighted Average Expected Life			1 year 3 months 19 days

Significant Accounting Polici46

Significant Accounting Policies (Other Than Temporary Impairment Credit Losses Recognized in Earnings) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,752,712
Reduction for credit losses:
Ending balance	3,170,467
OTTI on Retained CDO Bonds [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(491)	$ 3,196
Additions to credit losses:
On Retained CDO Bonds for which an OTTI was not previously recognized	0	0
On Retained CDO Bonds for which an OTTI was previously recognized and a portion of an OTTI was recognized in other comprehensive income (loss)	(4,890)	0
On Retained CDO Bonds for which an OTTI was previously recognized without any portion of OTTI recognized in other comprehensive income (loss)	0	0
Reduction for credit losses:
On Retained CDO Bonds for which no OTTI was recognized in other comprehensive income at current measurement date	0	0
On Retained CDO Bonds sold during the period	0	0
On Retained CDO Bonds charged off during the period	0	0
For increases in cash flows expected to be collected that are recognized over the remaining life of the Retained CDO Bonds	523	(3,687)
Ending balance	$ (4,858)	$ (491)

Dispositions, Assets Held for47

Dispositions, Assets Held for Sale, and Discontinued Operations (Narrative) (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017USD ($)Property	Mar. 31, 2017Property	Sep. 30, 2016USD ($)Property	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)Property	Sep. 30, 2017USD ($)land_parcel	Sep. 30, 2017USD ($)ft²	Sep. 30, 2016USD ($)Property	Sep. 30, 2017Property	Sep. 30, 2017land_parcel	Dec. 31, 2016Property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold			10					20
Proceeds from sale of property held-for-sale | $				$ 256,828
Net gain on disposals | $	$ 4,879		$ 2,336	24,258				$ 2,336
Properties sold at a gain	8				23
Impairment of real estate investments | $	$ (3,064)		$ (1,053)	(21,415)				$ (1,053)
Impairment charge | $	$ (7,973)
Properties impaired									4		1
Number of Acquisitions		21			74	2
Disposed by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold	8				25
Area of real estate properties sold | ft²							2,358,928
Assets Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Properties impaired									2
Number of properties held-for-sale									3	1	0
Net asset value | $	$ 12,378			12,378	$ 12,378	$ 12,378	$ 12,378
Exchange of Productive Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold					10
Proceeds from sale of property held-for-sale | $				176,895
Purchase price of real estate | $				$ 176,894
Number of Acquisitions					13
Offices [Member] | Disposed by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties sold					2

Dispositions, Assets Held for48

Dispositions, Assets Held for Sale, and Discontinued Operations (Summary of Assets and Liabilities Held-for-sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets held for sale
Total assets	$ 17,292	$ 0
Liabilities related to assets held for sale
Total liabilities	4,914	0
Assets Held-for-sale [Member]
Assets held for sale
Real estate investments	14,507
Acquired lease assets, net	2,503	0
Other assets	282
Total assets	17,292
Liabilities related to assets held for sale
Below-market lease liabilities, net	4,567	$ 0
Other liabilities	347
Total liabilities	4,914
Net assets held for sale	$ 12,378

Dispositions, Assets Held for49

Dispositions, Assets Held for Sale, and Discontinued Operations (Schedule of Operating Results of Assets Held-for-sale Including Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on extinguishment of debt	$ 0	$ 0	$ 0	$ 1,930
Income (loss) from discontinued operations	(24)	347	(76)	5,045
Assets Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	6	262	3	6,259
Operating expenses	0	(58)	6	(2,294)
General and administrative expense	(30)	(3)	(85)	(41)
Interest expense	0	148	0	(807)
Depreciation and amortization	0	(2)	0	(2)
Gain on extinguishment of debt	0	0	0	1,930
Income (loss) from discontinued operations	$ (24)	$ 347	$ (76)	$ 5,045

Dispositions, Assets Held for50

Dispositions, Assets Held for Sale, and Discontinued Operations (Schedule of Significant Operating and Investing Noncash Transactions) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amortization expense	$ 17	$ (3,636)
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amortization expense	0	2
Significant operating non-cash items	0	(9,647)
Total	$ 0	$ (9,645)

Real Estate Investments (Narrat

Real Estate Investments (Narrative) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2017Property	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)Property	Sep. 30, 2017USD ($)land_parcel	Sep. 30, 2017USD ($)ft²	Mar. 31, 2018USD ($)	Oct. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Number of Acquisitions	21		74	2
Square Feet | ft²					18,361,835
Purchase Price		$ 1,321,886
Acquisition of land		6,840
Buildings		4,845,246	$ 4,845,246	$ 4,845,246	$ 4,845,246			$ 4,053,125
Consolidated VIE [Member]
Business Acquisition [Line Items]
Purchase Price		29,605
Land [Member]
Business Acquisition [Line Items]
Purchase Price		2,400
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Real estate assets		1,226,190	1,226,190	1,226,190	1,226,190
Intangible Assets		125,882	125,882	125,882	125,882
Intangible Liabilities		15,834	$ 15,834	$ 15,834	15,834
Build-to-suit Property [Member]
Business Acquisition [Line Items]
Number of Acquisitions | Property			1
Purchase Price		63,244
Industrial Facility [Member]
Business Acquisition [Line Items]
Number of Acquisitions | land_parcel				2
Acquisition of land		2,800
Buildings		$ 49,077	$ 49,077	$ 49,077	$ 49,077
Scenario, Forecast [Member] | Industrial Facility [Member]
Business Acquisition [Line Items]
Buildings						$ 23,272	$ 25,805

Real Estate Investments (Proper

Real Estate Investments (Property Purchase Price Allocation) (Details) - 2016 Acquisitions Finalized [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Real Estate Properties [Line Items]
Real Estate Assets	$ 513,087
Intangible Assets	60,627
Intangible Liabilities	10,205
Decrease to Rental Revenue	27
Increase to Depreciation and Amortization Expense	16
Preliminary Allocations [Member]
Real Estate Properties [Line Items]
Real Estate Assets	513,424
Intangible Assets	61,178
Intangible Liabilities	$ 11,093

Unconsolidated Equity Investm53

Unconsolidated Equity Investments (Narrative) (Details) € in Thousands, $ in Thousands	Jun. 30, 2016USD ($)Property	Jun. 30, 2016EUR (€)Property	Jul. 31, 2017USD ($)Property	Jul. 31, 2017EUR (€)Property	Sep. 30, 2016Property	Sep. 30, 2017USD ($)ft²Propertyentityextension	Mar. 31, 2017Property	Sep. 30, 2016USD ($)Property	Sep. 30, 2017USD ($)ft²Propertyentityextension	Sep. 30, 2017USD ($)ft²Propertyentityextension	Sep. 30, 2017USD ($)ft²Propertyentityextension	Sep. 30, 2017USD ($)ft²Propertyland_parcelentityextension	Sep. 30, 2017EUR (€)	Sep. 30, 2016USD ($)Property	Sep. 30, 2017EUR (€)ft²Propertyentityextension	Dec. 31, 2016USD ($)Propertyentity	Dec. 31, 2015entity	Oct. 31, 2015
Investments in and Advances to Affiliates [Line Items]
Number of unconsolidated variable interest entities | entity						3			3	3	3	3			3	4	4
Number of Properties | Property						15			15	15	15	15			15	46
Proceeds from sale of investment										$ 87,229				$ 84,588
Gain (loss) from disposal of Company's interest						$ 0		$ 0		0				7,229
Investment in unconsolidated equity investment						73,163			$ 73,163	73,163	$ 73,163	$ 73,163				$ 101,807
Contributions to unconsolidated equity investments										20,775
Distributions received from unconsolidated equity investments										9,205				$ 48,235
Number of real estate properties sold | Property								10						20
Number of Acquisitions							21				74	2
Gramercy Europe Committed [Member]
Investments in and Advances to Affiliates [Line Items]
Initial equity capital available						$ 395,213			$ 395,213	$ 395,213	$ 395,213	$ 395,213			€ 352,500
Gramercy European Property Fund [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership interest sold			100.00%	100.00%
Number of Properties | Property			30	30		0			0	0	0	0			0	26
Ownership %						14.20%			14.20%	14.20%	14.20%	14.20%			14.20%	14.20%
Proceeds from sale of investment			$ 101,930	€ 89,366
Proceeds from sale, promoted interest distribution			$ 8,515	€ 7,448
Gain (loss) from disposal of Company's interest						$ 27,613
Write-off of accumulated other comprehensive income						(634)
Investment in unconsolidated equity investment						$ 1,109			$ 1,109	$ 1,109	$ 1,109	$ 1,109			€ 939	$ 50,367
Contributions to unconsolidated equity investments										$ 55,892			€ 50,000
Voting Interest %						14.20%			14.20%	14.20%	14.20%	14.20%			14.20%
Goodman Europe JV [Member]
Investments in and Advances to Affiliates [Line Items]
Number of Properties | Property			8	8		0			0	0	0	0			0	8
Ownership %			5.10%	5.10%	80.00%	0.00%		80.00%	0.00%	0.00%	0.00%	0.00%		80.00%	0.00%	5.10%
Proceeds from sale of investment	$ 148,884	€ 134,336
Gain (loss) from disposal of Company's interest	$ 5,341					$ 6,458
Write-off of accumulated other comprehensive income						145
Investment in unconsolidated equity investment						0			$ 0	$ 0	$ 0	$ 0				$ 3,491
Distributions received from unconsolidated equity investments						$ 0				$ 689
Voting Interest %			5.10%	5.10%		0.00%			0.00%	0.00%	0.00%	0.00%			0.00%
Strategic Office Partners [Member]
Investments in and Advances to Affiliates [Line Items]
Number of Properties | Property						11			11	11	11	11			11	6
Ownership %						25.00%			25.00%	25.00%	25.00%	25.00%			25.00%
Investment in unconsolidated equity investment						$ 35,760			$ 35,760	$ 35,760	$ 35,760	$ 35,760				$ 15,872
Contributions to unconsolidated equity investments						13,375				20,775
Distributions received from unconsolidated equity investments						2,710				2,710
Number of properties contributed | Property					6						6
Number of real estate properties sold | Property											1
Commitment amount						400,000			400,000	400,000	$ 400,000	400,000
Remaining commitment amount						$ 63,198			$ 63,198	$ 63,198	$ 63,198	$ 63,198
Voting Interest %						25.00%			25.00%	25.00%	25.00%	25.00%			25.00%
Strategic Office Partners [Member] | Parent Company [Member]
Investments in and Advances to Affiliates [Line Items]
Commitment amount						$ 100,000			$ 100,000	$ 100,000	$ 100,000	$ 100,000
Goodman UK JV [Member]
Investments in and Advances to Affiliates [Line Items]
Number of Properties | Property						1			1	1	1	1			1	2
Ownership %						80.00%			80.00%	80.00%	80.00%	80.00%			80.00%
Investment in unconsolidated equity investment						$ 30,884			$ 30,884	$ 30,884	$ 30,884	$ 30,884				$ 25,309
Voting Interest %						50.00%			50.00%	50.00%	50.00%	50.00%			50.00%
Duke JV [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership interest transferred	100.00%	100.00%
Number of Acquisitions | Property	7	7
CBRE Strategic Partners Asia [Member]
Investments in and Advances to Affiliates [Line Items]
Number of Properties | Property						1			1	1	1	1			1	2
Ownership %						5.07%			5.07%	5.07%	5.07%	5.07%			5.07%
Investment in unconsolidated equity investment						$ 2,772			$ 2,772	$ 2,772	$ 2,772	$ 2,772				$ 4,145
Distributions received from unconsolidated equity investments										$ 812
Number of real estate properties sold | Property											1
Term of agreement									8 years
Number of extensions | extension						2			2	2	2	2			2
Term of extensions									1 year
Voting Interest %						5.07%			5.07%	5.07%	5.07%	5.07%			5.07%
Phillips JV [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership %						25.00%			25.00%	25.00%	25.00%	25.00%			25.00%
Area of real estate property | ft²						199,900			199,900	199,900	199,900	199,900			199,900
Percentage of occupancy for leased office and industrial property						100.00%			100.00%	100.00%	100.00%	100.00%			100.00%
Morristown JV [Member]
Investments in and Advances to Affiliates [Line Items]
Number of Properties | Property						1			1	1	1	1			1	1
Ownership %						50.00%			50.00%	50.00%	50.00%	50.00%			50.00%	50.00%
Investment in unconsolidated equity investment						$ 2,638			$ 2,638	$ 2,638	$ 2,638	$ 2,638				$ 2,623
Voting Interest %						50.00%			50.00%	50.00%	50.00%	50.00%			50.00%			50.00%
Gramercy European Property Fund [Member] | Goodman Europe JV [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership %						94.90%			94.90%	94.90%	94.90%	94.90%			94.90%	94.90%
Duke Realty [Member]
Investments in and Advances to Affiliates [Line Items]
Number of Acquisitions | Property	1	1

Unconsolidated Equity Investm54

Unconsolidated Equity Investments (Summary of Unconsolidated Equity Investments) (Details) € in Thousands, $ in Thousands	1 Months Ended
	Jul. 31, 2017USD ($)Property	Sep. 30, 2017USD ($)Property	Sep. 30, 2017EUR (€)Property	Dec. 31, 2016USD ($)Property	Sep. 30, 2016	Oct. 31, 2015
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated equity investment		$ 73,163		$ 101,807
Number of Properties | Property		15	15	46
Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		14.20%	14.20%	14.20%
Voting Interest %		14.20%	14.20%
Investment in unconsolidated equity investment		$ 1,109	€ 939	$ 50,367
Number of Properties | Property	30	0	0	26
Ownership interest sold	100.00%
Amount held in escrow	$ 1,109
Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %	5.10%	0.00%	0.00%	5.10%	80.00%
Voting Interest %	5.10%	0.00%	0.00%
Investment in unconsolidated equity investment		$ 0		$ 3,491
Number of Properties | Property	8	0	0	8
Basis difference				$ 2,286
Goodman Europe JV [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		94.90%	94.90%	94.90%
Strategic Office Partners [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		25.00%	25.00%
Voting Interest %		25.00%	25.00%
Investment in unconsolidated equity investment		$ 35,760		$ 15,872
Number of Properties | Property		11	11	6
Goodman UK JV [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		80.00%	80.00%
Voting Interest %		50.00%	50.00%
Investment in unconsolidated equity investment		$ 30,884		$ 25,309
Number of Properties | Property		1	1	2
Basis difference		$ 1,930		$ 3,941
CBRE Strategic Partners Asia [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		5.07%	5.07%
Voting Interest %		5.07%	5.07%
Investment in unconsolidated equity investment		$ 2,772		$ 4,145
Number of Properties | Property		1	1	2
Philips JV [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		25.00%	25.00%
Voting Interest %		25.00%	25.00%
Investment in unconsolidated equity investment		$ 0		$ 0
Number of Properties | Property		1	1	1
Morristown JV [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		50.00%	50.00%	50.00%
Voting Interest %		50.00%	50.00%			50.00%
Investment in unconsolidated equity investment		$ 2,638		$ 2,623
Number of Properties | Property		1	1	1
Gramercy Europe Asset Management - European Fund Carry Co [Member]
Schedule of Equity Method Investments [Line Items]
Ownership %		25.00%	25.00%
Investment in unconsolidated equity investment		$ 284		$ 8

Unconsolidated Equity Investm55

Unconsolidated Equity Investments (Rollforward of Unconsolidated Equity Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Beginning balance			$ 101,807
Contributions to unconsolidated equity investments			20,775
Equity in net income of unconsolidated equity investments, including adjustments for basis differences	$ 48,730	$ (1,138)	48,884	$ (4,061)
Other comprehensive income of unconsolidated equity investments			7,286
Distributions from unconsolidated equity investments			(96,434)
Reclassification of unrealized gain of non-derivative net investment hedge into earnings	1,851	0	1,851	0
Sale of unconsolidated equity investment interests			(9,644)
Reclassification of accumulated foreign currency translation adjustments due to disposal	(1,362)	$ 0	(1,362)	$ (3,737)
Ending Balance	$ 73,163		$ 73,163

Unconsolidated Equity Investm56

Unconsolidated Equity Investments (Combined Balance Sheets for the Company's Joint Ventures) (Details) - USD ($) $ in Thousands	1 Months Ended
	Jul. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Gramercy Europe Asset Management - European Fund Carry Co [Member]
Liabilities and members' equity:
Ownership %		25.00%
Gramercy European Property Fund [Member]
Liabilities and members' equity:
Ownership interest sold	100.00%
Ownership %		14.20%	14.20%
Goodman Europe JV [Member]
Liabilities and members' equity:
Ownership %	5.10%	0.00%	5.10%	80.00%
Goodman Europe JV [Member] | Gramercy European Property Fund [Member]
Liabilities and members' equity:
Ownership %		94.90%	94.90%
Strategic Office Partners [Member]
Liabilities and members' equity:
Ownership %		25.00%
Goodman UK JV [Member]
Liabilities and members' equity:
Ownership %		80.00%
CBRE Strategic Partners Asia [Member]
Liabilities and members' equity:
Ownership %		5.07%
Corporate Joint Venture [Member]
Assets:
Real estate assets, net			$ 49,580
Other assets			3,020
Total assets			52,600
Liabilities and members' equity:
Mortgage notes payable			39,730
Other liabilities			3,259
Total liabilities			42,989
Company's equity			2,631
Other members' equity			6,980
Liabilities and members' equity			52,600
Corporate Joint Venture [Member] | Strategic Office Partners [Member]
Assets:
Real estate assets, net		$ 259,949	149,484
Other assets		57,319	42,323
Total assets		317,268	191,807
Liabilities and members' equity:
Mortgage notes payable		159,140	121,894
Other liabilities		13,008	4,347
Total liabilities		172,148	126,241
Company's equity		35,760	15,872
Other members' equity		109,360	49,694
Liabilities and members' equity		317,268	191,807
Corporate Joint Venture [Member] | Goodman UK JV [Member]
Assets:
Real estate assets, net		18,678	25,128
Other assets		20,314	6,650
Total assets		38,992	31,778
Liabilities and members' equity:
Mortgage notes payable		0	0
Other liabilities		194	934
Total liabilities		194	934
Company's equity		30,884	25,309
Other members' equity		7,914	5,535
Liabilities and members' equity		38,992	31,778
Corporate Joint Venture [Member] | CBRE Strategic Partners Asia [Member]
Assets:
Real estate assets, net		78,202	87,852
Other assets		11,214	12,247
Total assets		89,416	100,099
Liabilities and members' equity:
Mortgage notes payable		0	0
Other liabilities		14,677	14,383
Total liabilities		14,677	14,383
Company's equity		2,772	4,145
Other members' equity		71,967	81,571
Liabilities and members' equity		89,416	100,099
Corporate Joint Venture [Member] | Other [Member]
Assets:
Real estate assets, net		48,784
Other assets		4,217
Total assets		53,001
Liabilities and members' equity:
Mortgage notes payable		38,973
Other liabilities		3,407
Total liabilities		42,380
Company's equity		2,922
Other members' equity		7,699
Liabilities and members' equity		53,001
Europe [Member] | Corporate Joint Venture [Member] | Gramercy Europe Asset Management - European Fund Carry Co [Member]
Assets:
Total assets		1,192
Liabilities and members' equity:
Total liabilities		57
Company's equity		284
Other members' equity		851
Europe [Member] | Corporate Joint Venture [Member] | Gramercy European Property Fund [Member]
Assets:
Real estate assets, net		0	632,156
Other assets		12,084	149,796
Total assets		12,084	781,952
Liabilities and members' equity:
Mortgage notes payable		0	390,249
Other liabilities		5,126	27,718
Total liabilities		5,126	417,967
Company's equity		825	53,850
Other members' equity		6,133	310,135
Liabilities and members' equity		12,084	781,952
Europe [Member] | Corporate Joint Venture [Member] | Goodman Europe JV [Member]
Assets:
Real estate assets, net		0	285,087
Other assets		0	86,273
Total assets		0	371,360
Liabilities and members' equity:
Mortgage notes payable		0	174,269
Other liabilities		0	7,778
Total liabilities		0	182,047
Company's equity		0	12,734
Other members' equity		0	176,579
Liabilities and members' equity		0	371,360
Europe [Member] | Corporate Joint Venture [Member] | Gramercy European Property Fund (excluding legacy Goodman Europe Joint Venture) [Member]
Assets:
Real estate assets, net		0	347,069
Other assets		12,084	63,523
Total assets		12,084	410,592
Liabilities and members' equity:
Mortgage notes payable		0	215,980
Other liabilities		5,126	19,940
Total liabilities		5,126	235,920
Company's equity		825	41,116
Other members' equity		6,133	133,556
Liabilities and members' equity		$ 12,084	$ 410,592

Unconsolidated Equity Investm57

Unconsolidated Equity Investments (Real Estate Assets Subject to Mortgages) (Details) $ in Thousands	Sep. 30, 2017USD ($)Property	Jul. 31, 2017	Dec. 31, 2016USD ($)	Sep. 30, 2016
Schedule of Equity Method Investments [Line Items]
Percentage of face amount of debt presented	100.00%
Strategic Office Partners [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	25.00%
Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%		14.20%
Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	0.00%	5.10%	5.10%	80.00%
Phillips JV [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	25.00%
Wholly Owned Properties [Member] | Strategic Office Partners Portfolio [Member] | Strategic Office Partners [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	25.00%
Wholly Owned Properties [Member] | Durrholz [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Venray [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Lille [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Carlisle [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Oud-Beijerland [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Zaandam [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Kerkrade [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Friedrichspark [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Fredersdorf [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Breda [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Juechen [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Piaseczno [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Strykow [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Uden [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Rotterdam [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Frechen [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Meerane [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Amsterdam [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Tiel [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Netherlands Portfolio [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | Kutno [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Wholly Owned Properties [Member] | European Facility 1 [Member] | Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	18.60%
Wholly Owned Properties [Member] | European Facility 2 [Member] | Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	18.60%
Wholly Owned Properties [Member] | Worksop [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	14.20%
Interest Rate	3.94%
Wholly Owned Properties [Member] | Somerset [Member] | Phillips JV [Member]
Schedule of Equity Method Investments [Line Items]
Economic Ownership	25.00%
Interest Rate	6.90%
Mortgages [Member]
Schedule of Equity Method Investments [Line Items]
Total mortgage notes payable, net	$ 600,553
Mortgages [Member] | Wholly Owned Properties [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding Balance	201,053		$ 546,265
Net deferred financing costs and net debt premium (discount)	(2,940)		5,608
Total mortgage notes payable, net	$ 198,113		551,873
Mortgages [Member] | Wholly Owned Properties [Member] | Strategic Office Partners Portfolio [Member] | Strategic Office Partners [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	4.23%
Outstanding Balance	$ 162,080		125,000
Number of real estate properties pledged under debt | Property	9
Mortgages [Member] | Wholly Owned Properties [Member] | Durrholz [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.52%
Outstanding Balance	$ 0		12,289
Mortgages [Member] | Wholly Owned Properties [Member] | Venray [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	3.32%
Outstanding Balance	$ 0		13,015
Mortgages [Member] | Wholly Owned Properties [Member] | Lille [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	3.13%
Outstanding Balance	$ 0		27,081
Mortgages [Member] | Wholly Owned Properties [Member] | Carlisle [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	3.32%
Outstanding Balance	$ 0		10,443
Mortgages [Member] | Wholly Owned Properties [Member] | Oud-Beijerland [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	2.09%
Outstanding Balance	$ 0		8,077
Mortgages [Member] | Wholly Owned Properties [Member] | Zaandam [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	2.08%
Outstanding Balance	$ 0		11,647
Mortgages [Member] | Wholly Owned Properties [Member] | Kerkrade [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	2.08%
Outstanding Balance	$ 0		9,622
Mortgages [Member] | Wholly Owned Properties [Member] | Friedrichspark [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	2.08%
Outstanding Balance	$ 0		8,694
Mortgages [Member] | Wholly Owned Properties [Member] | Fredersdorf [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	2.08%
Outstanding Balance	$ 0		11,247
Mortgages [Member] | Wholly Owned Properties [Member] | Breda [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.90%
Outstanding Balance	$ 0		9,948
Mortgages [Member] | Wholly Owned Properties [Member] | Juechen [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.89%
Outstanding Balance	$ 0		18,852
Mortgages [Member] | Wholly Owned Properties [Member] | Piaseczno [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.98%
Outstanding Balance	$ 0		8,141
Mortgages [Member] | Wholly Owned Properties [Member] | Strykow [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.98%
Outstanding Balance	$ 0		19,167
Mortgages [Member] | Wholly Owned Properties [Member] | Uden [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.98%
Outstanding Balance	$ 0		8,913
Mortgages [Member] | Wholly Owned Properties [Member] | Rotterdam [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.89%
Outstanding Balance	$ 0		7,633
Mortgages [Member] | Wholly Owned Properties [Member] | Frechen [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.49%
Outstanding Balance	$ 0		6,043
Mortgages [Member] | Wholly Owned Properties [Member] | Meerane [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.35%
Outstanding Balance	$ 0		10,138
Mortgages [Member] | Wholly Owned Properties [Member] | Amsterdam [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.59%
Outstanding Balance	$ 0		3,093
Mortgages [Member] | Wholly Owned Properties [Member] | Tiel [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.59%
Outstanding Balance	$ 0		9,174
Mortgages [Member] | Wholly Owned Properties [Member] | Netherlands Portfolio [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	3.02%
Outstanding Balance	$ 0		13,409
Mortgages [Member] | Wholly Owned Properties [Member] | Kutno [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.91%
Outstanding Balance	$ 0		5,890
Mortgages [Member] | Wholly Owned Properties [Member] | European Facility [Member] | Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Number of real estate properties pledged under debt | Property	8
Mortgages [Member] | Wholly Owned Properties [Member] | European Facility 1 [Member] | Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	0.90%
Outstanding Balance	$ 0		31,551
Mortgages [Member] | Wholly Owned Properties [Member] | European Facility 2 [Member] | Goodman Europe JV [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	1.75%
Outstanding Balance	$ 0		106,917
Mortgages [Member] | Wholly Owned Properties [Member] | Worksop [Member] | Gramercy European Property Fund [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding Balance	0		10,551
Mortgages [Member] | Wholly Owned Properties [Member] | Somerset [Member] | Phillips JV [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding Balance	$ 38,973		$ 39,730

Unconsolidated Equity Investm58

Unconsolidated Equity Investments (Combined Income Statement for the Company's Joint Ventures) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Investments in and Advances to Affiliates [Line Items]
Gain (loss) from disposal of Company's interest	$ 0	$ 0	$ 0	$ 7,229
Company’s equity in net income (loss) within continuing operations	$ 48,730	(1,138)	48,884	(4,061)
Distributions received from unconsolidated equity investments			$ 9,205	48,235
Gramercy Europe Asset Management - European Fund Carry Co [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership %	25.00%		25.00%
Gramercy European Property Fund [Member]
Investments in and Advances to Affiliates [Line Items]
Gain (loss) from disposal of Company's interest	$ 27,613
Ownership %	14.20%		14.20%		14.20%
Strategic Office Partners [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership %	25.00%		25.00%
Distributions received from unconsolidated equity investments	$ 2,710		$ 2,710
Goodman UK JV [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership %	80.00%		80.00%
CBRE Strategic Partners Asia [Member]
Investments in and Advances to Affiliates [Line Items]
Ownership %	5.07%		5.07%
Distributions received from unconsolidated equity investments			$ 812
Corporate Joint Venture [Member] | Strategic Office Partners [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	$ 8,451	1,291	21,151	1,291
Operating expenses	2,828	280	6,618	280
Acquisition expenses		664		664
Interest expense	2,432	410	5,997	410
Depreciation and amortization	3,969	898	9,324	898
Total expenses	9,229	2,252	21,939	2,252
Net income (loss) from operations	(778)	(961)	(788)	(961)
Gain (loss) on derivatives	(144)	(129)	(906)	(129)
Loss on extinguishment of debt	(937)		(937)	0
Net gain on disposals	9,923	0	9,923	0
Provision for taxes	0	0	0	0
Net income (loss)	8,064	(1,090)	7,292	(1,090)
Company's share in net income (loss)	2,125	(273)	2,074	(273)
Adjustments for REIT basis	0	0	0	0
Gain (loss) from disposal of Company's interest	0		0
Corporate Joint Venture [Member] | Strategic Office Partners [Member] | Continuing Operations [Member]
Investments in and Advances to Affiliates [Line Items]
Company’s equity in net income (loss) within continuing operations	2,125	(273)	2,074	(273)
Corporate Joint Venture [Member] | Goodman UK JV [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	25	557	613	5,477
Operating expenses	82	225	609	698
Acquisition expenses		0		0
Interest expense	0	0	0	0
Depreciation and amortization	204	339	840	1,461
Total expenses	286	564	1,449	2,159
Net income (loss) from operations	(261)	(7)	(836)	3,318
Gain (loss) on derivatives	0	0	0	0
Loss on extinguishment of debt	0		0	0
Net gain on disposals	7,871	0	7,871	0
Provision for taxes	30	0	2	0
Net income (loss)	7,640	(7)	7,037	3,318
Company's share in net income (loss)	6,112	(6)	5,629	2,655
Adjustments for REIT basis	(2,159)	(183)	(2,288)	(461)
Gain (loss) from disposal of Company's interest	0		0
Corporate Joint Venture [Member] | Goodman UK JV [Member] | Continuing Operations [Member]
Investments in and Advances to Affiliates [Line Items]
Company’s equity in net income (loss) within continuing operations	3,953	(189)	3,341	2,194
Corporate Joint Venture [Member] | Duke Joint Venture [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues		417		19,812
Operating expenses		191		5,309
Acquisition expenses		0		0
Interest expense		0		602
Depreciation and amortization		0		7,154
Total expenses		191		13,065
Net income (loss) from operations		226		6,747
Gain (loss) on derivatives		0		0
Loss on extinguishment of debt				(7,962)
Net gain on disposals		28,170		66,705
Provision for taxes		0		0
Net income (loss)		28,396		65,490
Company's share in net income (loss)		20,749		50,424
Adjustments for REIT basis		(20,897)		(54,390)
Corporate Joint Venture [Member] | Duke Joint Venture [Member] | Continuing Operations [Member]
Investments in and Advances to Affiliates [Line Items]
Company’s equity in net income (loss) within continuing operations		(148)		(3,966)
Corporate Joint Venture [Member] | CBRE Strategic Partners Asia [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	(7,766)	(11,557)	(9,981)	(11,315)
Operating expenses	295	341	996	1,208
Acquisition expenses		0		0
Interest expense	0	0	0	0
Depreciation and amortization	0	0	0	0
Total expenses	295	341	996	1,208
Net income (loss) from operations	(8,061)	(11,898)	(10,977)	(12,523)
Gain (loss) on derivatives	0	0	0	0
Loss on extinguishment of debt	0		0	0
Net gain on disposals	0	0	0	0
Provision for taxes	0	0	0	0
Net income (loss)	(8,061)	(11,898)	(10,977)	(12,523)
Company's share in net income (loss)	(411)	(605)	(561)	(641)
Adjustments for REIT basis	0	0	0	0
Gain (loss) from disposal of Company's interest	0		0
Corporate Joint Venture [Member] | CBRE Strategic Partners Asia [Member] | Continuing Operations [Member]
Investments in and Advances to Affiliates [Line Items]
Company’s equity in net income (loss) within continuing operations	(411)	(605)	(561)	(641)
Corporate Joint Venture [Member] | Other [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	36,224	1,080	38,432	3,245
Operating expenses	170	129	444	342
Acquisition expenses		0		27
Interest expense	690	698	2,031	2,131
Depreciation and amortization	333	333	999	998
Total expenses	1,193	1,160	3,474	3,498
Net income (loss) from operations	35,031	(80)	34,958	(253)
Gain (loss) on derivatives	0	0	0	0
Loss on extinguishment of debt	0		0	0
Net gain on disposals	0	0	0	0
Provision for taxes	0	0	0	0
Net income (loss)	35,031	(80)	34,958	(253)
Company's share in net income (loss)	8,777	(4)	8,777	0
Adjustments for REIT basis	0	0	0	0
Gain (loss) from disposal of Company's interest	0		0
Corporate Joint Venture [Member] | Other [Member] | Continuing Operations [Member]
Investments in and Advances to Affiliates [Line Items]
Company’s equity in net income (loss) within continuing operations	8,777	(4)	8,777	0
Europe [Member] | Corporate Joint Venture [Member] | Gramercy Europe Asset Management - European Fund Carry Co [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	35,127		35,127
Total expenses	62		77
Net income (loss)	8,766		8,763
Europe [Member] | Corporate Joint Venture [Member] | Gramercy European Property Fund [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	896	13,524	32,771	36,659
Operating expenses	(1,255)	2,295	6,365	5,560
Acquisition expenses		2,141		9,638
Interest expense	181	1,791	4,739	5,551
Depreciation and amortization	357	6,076	14,197	15,539
Total expenses	(717)	12,303	25,301	36,288
Net income (loss) from operations	1,613	1,221	7,470	371
Gain (loss) on derivatives	(22)	(1,124)	2,248	(6,428)
Loss on extinguishment of debt	0		0	0
Net gain on disposals	230,392	0	230,392	0
Provision for taxes	(106)	(284)	(416)	(876)
Net income (loss)	231,877	(187)	239,694	(6,933)
Company's share in net income (loss)	32,931	70	33,971	(1,830)
Adjustments for REIT basis	0	11	(73)	455
Gain (loss) from disposal of Company's interest	1,355		1,355
Europe [Member] | Corporate Joint Venture [Member] | Gramercy European Property Fund [Member] | Continuing Operations [Member]
Investments in and Advances to Affiliates [Line Items]
Company’s equity in net income (loss) within continuing operations	$ 34,286	$ 81	$ 35,253	$ (1,375)

Debt Obligations (Secured Debt)

Debt Obligations (Secured Debt) (Narrative) (Details) $ in Thousands	3 Months Ended			9 Months Ended					12 Months Ended
	Sep. 30, 2017USD ($)	Mar. 31, 2017Property	Sep. 30, 2016USD ($)Property	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)Property	Sep. 30, 2017USD ($)land_parcel	Sep. 30, 2017USD ($)mortgage	Sep. 30, 2016USD ($)Propertymortgage	Dec. 31, 2016USD ($)Property
Debt Instrument [Line Items]
Number of Acquisitions		21			74	2
Number of real estate properties in which secured debt repaid | Property					2
Loss on extinguishment of debt	$ (6,751)		$ (13,777)	$ (6,691)				$ (20,890)
Gain on extinguishment of debt, discontinued operations	0		$ 0	0				$ 1,930
Mortgages [Member]
Debt Instrument [Line Items]
Number of real estate properties in which secured debt repaid | Property			14		2			22
Refinance amount				10,456
Mortgages transferred | mortgage							2	1
Loss on extinguishment of debt	0			(60)
Series of Individually Immaterial Business Acquisitions [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Non-recourse debt	$ 114,649			$ 114,649	$ 114,649	$ 114,649	$ 114,649		$ 244,188
Number of Acquisitions | Property					5				27
Mortgages [Member]
Debt Instrument [Line Items]
Debt amount extinguished			$ 124,605
Properties in which debt was released | Property			11
US Treasury Securities [Member]
Debt Instrument [Line Items]
Treasury securities, value			$ 144,063					$ 144,063

Debt Obligations (Schedule of M

Debt Obligations (Schedule of Mortgage Notes Payable) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)PropertySecurityLoan	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Number of loans cross collateralized by properties | SecurityLoan	5
Number of real estate properties in which secured debt repaid | Property	2
Mortgage Notes Payable [Member]
Debt Instrument [Line Items]
Outstanding Balance	$ 600,553	$ 555,484
Net deferred financing costs and net debt premium (discount)	6,345	3,158
Total mortgage notes payable, net	$ 606,898	558,642
Mortgage Notes Payable [Member] | Dallas [Member]
Debt Instrument [Line Items]
Interest Rate	3.05%
Outstanding Balance	$ 9,372	9,540
Mortgage Notes Payable [Member] | Jacksonville [Member]
Debt Instrument [Line Items]
Interest Rate	3.05%
Outstanding Balance	$ 6,732	6,852
Mortgage Notes Payable [Member] | Cincinnati [Member]
Debt Instrument [Line Items]
Interest Rate	3.29%
Outstanding Balance	$ 6,512	6,628
Mortgage Notes Payable [Member] | Minneapolis [Member]
Debt Instrument [Line Items]
Interest Rate	3.05%
Outstanding Balance	$ 5,896	6,001
Mortgage Notes Payable [Member] | Phoenix [Member]
Debt Instrument [Line Items]
Interest Rate	3.05%
Outstanding Balance	$ 4,048	4,120
Mortgage Notes Payable [Member] | Ames [Member]
Debt Instrument [Line Items]
Interest Rate	5.05%
Outstanding Balance	$ 16,069	16,436
Mortgage Notes Payable [Member] | Columbus [Member]
Debt Instrument [Line Items]
Interest Rate	4.01%
Outstanding Balance	$ 19,006	19,708
Mortgage Notes Payable [Member] | Greenwood [Member]
Debt Instrument [Line Items]
Interest Rate	3.59%
Outstanding Balance	$ 7,302	7,436
Mortgage Notes Payable [Member] | Greenfield [Member]
Debt Instrument [Line Items]
Interest Rate	3.63%
Outstanding Balance	$ 5,902	6,010
Mortgage Notes Payable [Member] | Logistics Portfolio - Pool 3 [Member]
Debt Instrument [Line Items]
Interest Rate	3.96%
Outstanding Balance	$ 43,300	43,300
Number of real estate properties pledged under debt | Property	2
Mortgage Notes Payable [Member] | Philadelphia [Member]
Debt Instrument [Line Items]
Interest Rate	4.99%
Outstanding Balance	$ 12,041	12,328
Mortgage Notes Payable [Member] | Columbus [Member]
Debt Instrument [Line Items]
Interest Rate	3.94%
Outstanding Balance	$ 5,768	5,908
Mortgage Notes Payable [Member] | Bridgeview [Member]
Debt Instrument [Line Items]
Interest Rate	3.90%
Outstanding Balance	$ 5,883	6,014
Mortgage Notes Payable [Member] | Spartanburg [Member]
Debt Instrument [Line Items]
Interest Rate	3.20%
Outstanding Balance	$ 732	1,025
Mortgage Notes Payable [Member] | Charleston [Member]
Debt Instrument [Line Items]
Interest Rate	3.11%
Outstanding Balance	$ 591	986
Mortgage Notes Payable [Member] | Lawrence [Member]
Debt Instrument [Line Items]
Interest Rate	5.02%
Outstanding Balance	$ 20,224	20,703
Mortgage Notes Payable [Member] | Charlotte [Member]
Debt Instrument [Line Items]
Interest Rate	3.28%
Outstanding Balance	$ 1,711	2,217
Mortgage Notes Payable [Member] | Hawthorne [Member]
Debt Instrument [Line Items]
Interest Rate	3.52%
Outstanding Balance	$ 17,327	17,638
Mortgage Notes Payable [Member] | Charleston [Member]
Debt Instrument [Line Items]
Interest Rate	3.32%
Outstanding Balance	$ 820	1,001
Mortgage Notes Payable [Member] | Charleston [Member]
Debt Instrument [Line Items]
Interest Rate	2.97%
Outstanding Balance	$ 806	984
Mortgage Notes Payable [Member] | Charleston [Member]
Debt Instrument [Line Items]
Interest Rate	3.37%
Outstanding Balance	$ 806	984
Mortgage Notes Payable [Member] | Charlotte [Member]
Debt Instrument [Line Items]
Interest Rate	3.38%
Outstanding Balance	$ 700	853
Mortgage Notes Payable [Member] | Des Plaines [Member]
Debt Instrument [Line Items]
Interest Rate	5.54%
Outstanding Balance	$ 2,405	2,463
Mortgage Notes Payable [Member] | Waco [Member]
Debt Instrument [Line Items]
Interest Rate	4.75%
Outstanding Balance	$ 14,964	15,187
Mortgage Notes Payable [Member] | Deerfield [Member]
Debt Instrument [Line Items]
Interest Rate	3.71%
Outstanding Balance	$ 10,538	10,804
Mortgage Notes Payable [Member] | Winston-Salem [Member]
Debt Instrument [Line Items]
Interest Rate	3.41%
Outstanding Balance	$ 3,569	4,199
Mortgage Notes Payable [Member] | Winston-Salem [Member]
Debt Instrument [Line Items]
Interest Rate	3.42%
Outstanding Balance	$ 1,184	1,388
Mortgage Notes Payable [Member] | Logistics Portfolio - Pool 1 [Member]
Debt Instrument [Line Items]
Interest Rate	4.27%
Outstanding Balance	$ 38,355	39,002
Number of real estate properties pledged under debt | Property	3
Mortgage Notes Payable [Member] | CCC Portfolio [Member]
Debt Instrument [Line Items]
Interest Rate	4.24%
Outstanding Balance	$ 22,933	23,280
Number of real estate properties pledged under debt | Property	5
Mortgage Notes Payable [Member] | Logistics Portfolio - Pool 4 [Member]
Debt Instrument [Line Items]
Interest Rate	4.36%
Outstanding Balance	$ 79,500	79,500
Number of real estate properties pledged under debt | Property	6
Mortgage Notes Payable [Member] | KIK USA Portfolio [Member]
Debt Instrument [Line Items]
Interest Rate	4.31%
Outstanding Balance	$ 7,230	7,450
Number of real estate properties pledged under debt | Property	3
Mortgage Notes Payable [Member] | Yuma [Member]
Debt Instrument [Line Items]
Interest Rate	5.27%
Outstanding Balance	$ 11,909	12,058
Mortgage Notes Payable [Member] | Allentown [Member]
Debt Instrument [Line Items]
Interest Rate	5.16%
Outstanding Balance	$ 22,790	23,078
Mortgage Notes Payable [Member] | Spartanburg [Member]
Debt Instrument [Line Items]
Interest Rate	3.72%
Outstanding Balance	$ 5,821	6,360
Mortgage Notes Payable [Member] | Maple Grove [Member]
Debt Instrument [Line Items]
Interest Rate	3.88%
Outstanding Balance	$ 16,468	0
Mortgage Notes Payable [Member] | Curtis Bay [Member]
Debt Instrument [Line Items]
Interest Rate	4.31%
Outstanding Balance	$ 13,500	0
Mortgage Notes Payable [Member] | Rialto [Member]
Debt Instrument [Line Items]
Interest Rate	3.91%
Outstanding Balance	$ 54,940	0
Mortgage Notes Payable [Member] | Durham [Member]
Debt Instrument [Line Items]
Interest Rate	4.02%
Outstanding Balance	$ 3,648	0
Mortgage Notes Payable [Member] | Houston [Member]
Debt Instrument [Line Items]
Interest Rate	3.68%
Outstanding Balance	$ 26,000	0
Mortgage Notes Payable [Member] | Charleston [Member]
Debt Instrument [Line Items]
Interest Rate	3.80%
Outstanding Balance	$ 6,169	6,658
Mortgage Notes Payable [Member] | Hackettstown [Member]
Debt Instrument [Line Items]
Interest Rate	5.49%
Outstanding Balance	$ 9,488	9,550
Mortgage Notes Payable [Member] | Hutchins [Member]
Debt Instrument [Line Items]
Interest Rate	5.41%
Outstanding Balance	$ 21,883	22,764
Mortgage Notes Payable [Member] | Logistics Portfolio - Pool 2 [Member]
Debt Instrument [Line Items]
Interest Rate	4.48%
Outstanding Balance	$ 35,711	36,279
Number of real estate properties pledged under debt | Property	5
Mortgage Notes Payable [Member] | Buford [Member]
Debt Instrument [Line Items]
Interest Rate	4.67%
Outstanding Balance	$ 0	15,512
Mortgage Notes Payable [Member] | Woodcliff Lake [Member]
Debt Instrument [Line Items]
Interest Rate	3.04%
Outstanding Balance	$ 0	35,366
Mortgage Notes Payable [Member] | KIK Canada Portfolio [Member]
Debt Instrument [Line Items]
Interest Rate	3.57%
Outstanding Balance	$ 0	$ 7,914
Number of real estate properties in which secured debt repaid | Property	2

Debt Obligations (Unsecured Deb

Debt Obligations (Unsecured Debt) (Narrative) (Details)	1 Months Ended	9 Months Ended
	Dec. 31, 2015USD ($)	Sep. 30, 2017extension	Dec. 31, 2016USD ($)
Unsecured Debt [Member] | 2015 Revolving Credit Facility - U.S. Dollar Tranche [Member]
Debt Instrument [Line Items]
Interest Rate		2.20%
Unsecured Debt [Member] | 2015 Revolving Credit Facility - Multicurrency Tranche [Member]
Debt Instrument [Line Items]
Interest Rate		1.20%
Unsecured Debt [Member] | 3-Year Term Loan [Member]
Debt Instrument [Line Items]
Interest Rate		2.35%
Unsecured Debt [Member] | 7-Year Term Loan [Member]
Debt Instrument [Line Items]
Interest Rate		2.76%
Unsecured Debt [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Face amount			$ 500,000,000
JPMorgan Chase Bank [Member] | 2015 Revolving Credit Facility - U.S. Dollar Tranche [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,900,000,000
Line of credit facility, number of extensions | extension		2
JPMorgan Chase Bank [Member] | Term Loans [Member] | 3-Year Term Loan [Member]
Debt Instrument [Line Items]
Face amount	300,000,000
JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, number of extensions | extension		1
JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.50%
JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member] | LIBOR 30-Day [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.00%
JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Face amount	850,000,000
JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | 2015 Revolving Credit Facility - US Dollars Tranche [Member]
Debt Instrument [Line Items]
Face amount	750,000,000
JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | 2015 Revolving Credit Facility - Multicurrency Tranche [Member]
Debt Instrument [Line Items]
Face amount	100,000,000
JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | Term Loans [Member] | Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Face amount	1,050,000,000
Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member]
Debt Instrument [Line Items]
Face amount	$ 175,000,000
Term of debt	7 years
Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.50%
Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member] | LIBOR 30-Day [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.00%
Minimum [Member] | Unsecured Debt [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Interest Rate			3.89%
Minimum [Member] | JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.90%
Minimum [Member] | JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.00%
Minimum [Member] | JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Commitment fee percentage		0.125%
Minimum [Member] | JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.875%
Minimum [Member] | JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.00%
Minimum [Member] | Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.30%
Minimum [Member] | Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.30%
Maximum [Member] | Unsecured Debt [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Interest Rate			4.97%
Maximum [Member] | JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.75%
Maximum [Member] | JPMorgan Chase Bank [Member] | Term Loans [Member] | JPM Term Loan [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.75%
Maximum [Member] | JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Commitment fee percentage		0.30%
Maximum [Member] | JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.55%
Maximum [Member] | JPMorgan Chase Bank [Member] | Revolving Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.55%
Maximum [Member] | Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.10%
Maximum [Member] | Capital One [Member] | Term Loans [Member] | 7-Year Term Loan [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.10%

Debt Obligations (Exchangeable

Debt Obligations (Exchangeable Senior Notes) (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Mar. 18, 2014
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ 6,751	$ 13,777	$ 6,691	$ 20,890
Reclassification of fair value of embedded exchange option on 3.75% exchangeable senior notes				$ 11,726
Convertible Debt [Member] | Exchangeable Senior Notes 3.75% [Member]
Debt Instrument [Line Items]
Face amount							$ 115,000
Interest Rate	3.75%	3.75%		3.75%
Percent of instrument converted	100.00%
Shares issued in conversion (in shares)	5,258,420
Debt, fair value	$ 117,450	$ 117,450		$ 117,450			$ 106,689
Loss on extinguishment of debt				6,751
Adjustment to APIC related to extinguishment of exchangeable notes		$ (42,065)		$ (42,065)
Carrying value of discount						$ 108,832
Unamortized discount and deferred financing costs						$ 6,168

Debt Obligations (Schedule of C

Debt Obligations (Schedule of Credit Facilities and Term Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
2015 Revolving Credit Facility - U.S. Dollar Tranche [Member]
Line of Credit Facility [Line Items]
Long-term Debt	$ 615,097
Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Outstanding Balance	2,340,097	$ 1,905,837
Unamortized discount and deferred financing costs	(3,316)	(9,704)
Long-term Debt	$ 2,336,781	1,896,133
Unsecured Debt [Member] | 2015 Revolving Credit Facility - U.S. Dollar Tranche [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	2.20%
Effective Interest Rate	2.20%
Outstanding Balance	$ 595,000	0
Unsecured Debt [Member] | 2015 Revolving Credit Facility - Multicurrency Tranche [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	1.20%
Effective Interest Rate	1.20%
Outstanding Balance	$ 20,097	65,837
Unsecured Debt [Member] | 3-Year Term Loan [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	2.35%
Effective Interest Rate	2.33%
Outstanding Balance	$ 300,000	300,000
Unsecured Debt [Member] | 5-Year Term Loan [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	2.35%
Effective Interest Rate	2.70%
Outstanding Balance	$ 750,000	750,000
Unsecured Debt [Member] | 7-Year Term Loan [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	2.76%
Effective Interest Rate	3.34%
Outstanding Balance	$ 175,000	175,000
Unsecured Debt [Member] | 2015 Senior Notes Due 2024 [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	4.97%
Effective Interest Rate	5.07%
Outstanding Balance	$ 150,000	150,000
Unsecured Debt [Member] | 2016 Senior Notes Due 2022 [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	3.89%
Effective Interest Rate	4.00%
Outstanding Balance	$ 150,000	150,000
Unsecured Debt [Member] | 2016 Senior Notes Due 2025 [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	4.26%
Effective Interest Rate	4.38%
Outstanding Balance	$ 100,000	100,000
Unsecured Debt [Member] | 2016 Senior Notes Due 2026 [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	4.32%
Effective Interest Rate	4.43%
Outstanding Balance	$ 100,000	100,000
Unsecured Debt [Member] | Exchangeable Senior Notes [Member]
Line of Credit Facility [Line Items]
Stated Interest Rate	3.75%
Effective Interest Rate	6.36%
Outstanding Balance	$ 0	$ 115,000

Debt Obligations (Schedule of64

Debt Obligations (Schedule of Maturities of Long-term Debt) (Details) $ in Thousands	Sep. 30, 2017USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
Above market interest	$ 3,029
Long-term Debt, Interest Payments, Fiscal Year Maturity [Abstract]
October 1 to December 31, 2017, interest	28,780
2018, interest	94,453
2019, interest	86,650
2020, interest	69,801
2021, interest	44,158
Thereafter, interest	43,378
Interest payments, total	370,249
Long-term Debt and Interest, Fiscal Year Maturity [Abstract]
October 1 to December 31, 2017, total	32,853
2018, total	266,441
2019, total	421,653
2020, total	746,701
2021, total	812,311
Thereafter, total	1,027,911
Net premium, total	3,310,899
2015 Revolving Credit Facility [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
October 1 to December 31, 2017	0
2,018	0
2,019	0
2,020	615,097
2,021	0
Thereafter	0
Above market interest	0
Long-term Debt	615,097
Senior Unsecured Notes [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
October 1 to December 31, 2017	0
2,018	0
2,019	0
2,020	0
2,021	0
Thereafter	500,000
Above market interest	0
Long-term Debt	500,000
Term Loans [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
October 1 to December 31, 2017	0
2,018	0
2,019	300,000
2,020	0
2,021	750,000
Thereafter	175,000
Above market interest	0
Long-term Debt	1,225,000
Mortgage Notes Payable [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
October 1 to December 31, 2017	4,073
2,018	171,988
2,019	35,003
2,020	61,803
2,021	18,153
Thereafter	309,533
Above market interest	0
Long-term Debt	$ 600,553

Leasing Agreements (Schedule of

Leasing Agreements (Schedule of Future Minimum Rental Payments) (Details) $ in Thousands	Sep. 30, 2017USD ($)
Leases, Operating [Abstract]
October 1 to December 31, 2017	$ 112,429
2,018	450,096
2,019	424,686
2,020	396,516
2,021	362,870
Thereafter	1,973,979
Total minimum lease rental income	$ 3,720,576

Transactions with Trustee Rel66

Transactions with Trustee Related Entities and Related Parties (Narrative) (Details) € in Thousands, $ in Thousands	Jun. 30, 2016USD ($)	Jun. 30, 2016EUR (€)	May 31, 2016ft²Property	Jul. 31, 2017USD ($)Property	Jul. 31, 2017EUR (€)Property	Dec. 31, 2016USD ($)Property	Dec. 31, 2016EUR (€)	Sep. 30, 2017USD ($)Propertydirector	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Propertydirector	Sep. 30, 2016USD ($)	Sep. 30, 2017EUR (€)Propertydirector	Dec. 31, 2014
Related Party Transaction [Line Items]
Number of Properties | Property						46		15		15		15
Proceeds from sale of investment										$ 87,229	$ 84,588
Gain on sale of investment								$ 0	$ 0	0	7,229
Investments in joint ventures						$ 101,807		73,163		73,163
Duke Realty [Member]
Related Party Transaction [Line Items]
Amount of related party transaction											$ 333
Lille [Member] | Gramercy European Property Fund [Member]
Related Party Transaction [Line Items]
Proceeds from sale of real estate						$ 2,662	€ 2,563
Minnesota [Member] | Duke Realty [Member]
Related Party Transaction [Line Items]
Real estate properties partially leased | Property			1			1
Area of property leased | ft²			30,777
Area of real estate property | ft²			322,551
The Company [Member] | Gramercy Europe [Member]
Related Party Transaction [Line Items]
Initial equity capital available								55,892		55,892		€ 50,000
Chief Executive Officer [Member] | Gramercy Europe [Member]
Related Party Transaction [Line Items]
Investments in joint ventures								1,388		1,388		1,250
Managing Directors [Member] | Gramercy Europe [Member]
Related Party Transaction [Line Items]
Investments in joint ventures								$ 1,388		$ 1,388		€ 1,250
Goodman Europe JV [Member]
Related Party Transaction [Line Items]
Ownership %				5.10%	5.10%	5.10%		0.00%	80.00%	0.00%	80.00%	0.00%
Number of Properties | Property				8	8	8		0		0		0
Proceeds from sale of investment	$ 148,884	€ 134,336
Gain on sale of investment	$ 5,341							$ 6,458
Goodman Europe JV [Member] | Gramercy European Property Fund [Member]
Related Party Transaction [Line Items]
Ownership %						94.90%		94.90%		94.90%		94.90%
Ownership percentage acquired			20.00%						74.90%
Goodman Europe JV [Member] | Lille [Member]
Related Party Transaction [Line Items]
Number of Properties | Property						1
Gramercy European Property Fund [Member]
Related Party Transaction [Line Items]
Ownership %						14.20%		14.20%		14.20%		14.20%
Number of Properties | Property				30	30	26		0		0		0
Ownership interest sold				100.00%	100.00%
Proceeds from sale of investment				$ 101,930	€ 89,366
Gain on sale of investment								$ 27,613
Gramercy Europe Asset [Member]
Related Party Transaction [Line Items]
Ownership %													50.00%
Number of managing directors | director								2		2		2

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)Property	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Property	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)Property
Fair Value Disclosures [Abstract]
Change in net unrealized gain (loss) on derivative instruments	$ 2,959	$ 7,653	$ 4,645	$ (25,996)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties impaired | Property	4		4		1
Held for Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties impaired | Property	2		2
Assets Held-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties impaired | Property	2		2
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset value	$ 31,743		$ 31,743		$ 22,233
Real Estate Investments [Member] | Estimate of Fair Value Measurement [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset value	$ 14,561		$ 14,561		2,413
Real Estate Investments [Member] | Estimate of Fair Value Measurement [Member] | Investments [Member] | Held for Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset value					10,400
Real Estate Investments [Member] | Estimate of Fair Value Measurement [Member] | Investments [Member] | Assets Held-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset value					$ 4,161

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Carrying Value and Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Retained CDO Bonds [Member]
Financial assets:
Investments	$ 6,167
Carrying Value [Member]
Long-term debt
2015 Revolving Credit Facility	615,097	$ 65,837
Mortgage notes payable	606,898	558,642
Carrying Value [Member] | 3-Year Term Loan [Member]
Long-term debt
Term loans	300,000	300,000
Carrying Value [Member] | 5-Year Term Loan [Member]
Long-term debt
Term loans	750,000	750,000
Carrying Value [Member] | 7-Year Term Loan [Member]
Long-term debt
Term loans	175,000	175,000
Carrying Value [Member] | Senior Unsecured Notes [Member]
Long-term debt
Senior notes	496,684	496,464
Carrying Value [Member] | Exchangeable Senior Notes [Member]
Long-term debt
Senior notes	0	108,832
Carrying Value [Member] | Interest Rate Swap [Member]
Financial assets:
Interest rate swaps	8,243	3,769
Financial liabilities:
Interest rate swaps	391	700
Carrying Value [Member] | Retained CDO Bonds [Member]
Financial assets:
Investments	6,167	11,906
Carrying Value [Member] | Investment in CBRE Strategic Partners Asia [Member]
Financial assets:
Investments	2,772	4,145
Carrying Value [Member] | Real Estate Investments [Member]
Financial assets:
Investments	14,561	2,413
Fair Value [Member]
Long-term debt
2015 Revolving Credit Facility	612,120	65,897
Mortgage notes payable	618,097	567,705
Fair Value [Member] | 3-Year Term Loan [Member]
Long-term debt
Term loans	299,180	300,213
Fair Value [Member] | 5-Year Term Loan [Member]
Long-term debt
Term loans	744,851	750,959
Fair Value [Member] | 7-Year Term Loan [Member]
Long-term debt
Term loans	176,516	172,850
Fair Value [Member] | Senior Unsecured Notes [Member]
Long-term debt
Senior notes	508,547	498,650
Fair Value [Member] | Exchangeable Senior Notes [Member]
Long-term debt
Senior notes	0	115,625
Fair Value [Member] | Interest Rate Swap [Member]
Financial assets:
Interest rate swaps	8,243	3,769
Financial liabilities:
Interest rate swaps	391	700
Fair Value [Member] | Retained CDO Bonds [Member]
Financial assets:
Investments	6,167	11,906
Fair Value [Member] | Investment in CBRE Strategic Partners Asia [Member]
Financial assets:
Investments	2,772	4,145
Fair Value [Member] | Real Estate Investments [Member]
Financial assets:
Investments	$ 14,561	$ 2,413

Fair Value Measurements (Sche69

Fair Value Measurements (Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis) (Details) - Estimate of Fair Value Measurement [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	$ 31,743	$ 22,233
Financial Liabilities:	(391)	(700)
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities:	(391)	(700)
Retained CDO Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	6,167	11,906
Investments [Member] | Real Estate Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	14,561	2,413
Investments [Member] | Investment in CBRE Strategic Partners Asia [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	2,772	4,145
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	8,243	3,769
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Financial Liabilities:	0	0
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities:	0	0
Fair Value, Inputs, Level 1 [Member] | Retained CDO Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 1 [Member] | Investments [Member] | Real Estate Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 1 [Member] | Investments [Member] | Investment in CBRE Strategic Partners Asia [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Financial Liabilities:	0	0
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities:	0	0
Fair Value, Inputs, Level 2 [Member] | Retained CDO Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 2 [Member] | Investments [Member] | Real Estate Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 2 [Member] | Investments [Member] | Investment in CBRE Strategic Partners Asia [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	31,743	22,233
Financial Liabilities:	(391)	(700)
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities:	(391)	(700)
Fair Value, Inputs, Level 3 [Member] | Retained CDO Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	6,167	11,906
Fair Value, Inputs, Level 3 [Member] | Investments [Member] | Real Estate Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	14,561	2,413
Fair Value, Inputs, Level 3 [Member] | Investments [Member] | Investment in CBRE Strategic Partners Asia [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	2,772	4,145
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets:	$ 8,243	$ 3,769

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value, Assets and Liabilities Measured on Recurring Basis, Valuation Techniques) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liabilities fair value	$ 391	$ 700
CBRE Strategic Partners Asia [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value	$ 2,772
Discount rate	20.00%
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Fair Value	$ 7,852
Interest Rate Swap [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liabilities fair value	$ 391	700
Minimum [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	1.35%
Maximum [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	2.05%
Non-investment grade, subordinate CDO bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value	$ 6,167
Discount rate	16.50%
Non-investment grade, subordinate CDO bonds [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value	$ 6,167	$ 11,906

Fair Value Measurements (Fair71

Fair Value Measurements (Fair Value, Assets (Liabilities) Measured on Recurring Basis, Unobservable Input Reconciliation) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 19,120
Amortization of discounts or premiums	1,353
Adjustments to fair value:
Unrealized loss in other comprehensive income from fair value adjustment	(2,202)
Other-than-temporary impairments	(4,890)
Total loss on fair value adjustments	(561)
Distributions from financial assets	(812)
Ending balance	16,791
Adjustments To Fair Value, Assets (Liabilities) [Abstract]
Ineffective portion of change in derivative instruments	138
Unrealized gain on derivatives	4,645
Interest Rate Swap [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3,069
Adjustments To Fair Value, Assets (Liabilities) [Abstract]
Ineffective portion of change in derivative instruments	138
Unrealized gain on derivatives	4,645
Ending balance	7,852
Investment in CBRE Strategic Partners Asia [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	4,145
Adjustments to fair value:
Total loss on fair value adjustments	(561)
Distributions from financial assets	(812)
Ending balance	2,772
Retained CDO Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	11,906
Amortization of discounts or premiums	1,353
Adjustments to fair value:
Unrealized loss in other comprehensive income from fair value adjustment	(2,202)
Other-than-temporary impairments	(4,890)
Ending balance	$ 6,167

Derivatives and Non-Derivativ72

Derivatives and Non-Derivative Hedging Instruments (Schedule of Derivative Instruments) (Details) - Sep. 30, 2017 £ in Thousands, $ in Thousands	USD ($)instrument	GBP (£)instrument
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Fair Value	$ 7,852
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 4.55% [Member]
Derivative [Line Items]
Notional Value	$ 14,964
Strike Rate	4.55%	4.55%
Fair Value	$ (313)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.78% [Member]
Derivative [Line Items]
Notional Value	$ 19,006
Strike Rate	1.78%	1.78%
Fair Value	$ (48)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.95% [Member]
Derivative [Line Items]
Notional Value	$ 5,768
Strike Rate	1.95%	1.95%
Fair Value	$ (31)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.22% [Member]
Derivative [Line Items]
Notional Value	$ 100,000
Strike Rate	1.22%	1.22%
Fair Value	$ 375
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.23% [Member]
Derivative [Line Items]
Notional Value	$ 100,000
Strike Rate	1.23%	1.23%
Fair Value	$ 370
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.24% [Member]
Derivative [Line Items]
Notional Value	$ 100,000
Strike Rate	1.24%	1.24%
Fair Value	$ 357
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.60% [Member]
Derivative [Line Items]
Notional Value	$ 750,000
Strike Rate	1.60%	1.60%
Fair Value	$ 4,352
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Strike Rate 1.82% [Member]
Derivative [Line Items]
Notional Value	$ 175,000
Strike Rate	1.82%	1.82%
Fair Value	$ 739
Not Designated as Hedging Instrument [Member] | Forward Starting Swap [Member]
Derivative [Line Items]
Notional Value	$ 250,000
Strike Rate	2.23%	2.23%
Fair Value	$ 2,051
Not Designated as Hedging Instrument [Member] | Net Investment Hedge in GBP-denominated Investments [Member]
Derivative [Line Items]
Notional Value | £		£ 15,000
Fair Value	$ 0
Designated as Hedging Instrument [Member] | Forward Starting Swap [Member]
Derivative [Line Items]
Number of derivative instruments | instrument	1	1

Derivatives and Non-Derivativ73

Derivatives and Non-Derivative Hedging Instruments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)instrument	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)instrument	Sep. 30, 2016USD ($)
Derivative [Line Items]
Gain on derivative	$ 92	$ 83	$ 138	$ 817
Interest expense	24,266	18,409	70,561	57,271
Reclassification of unrealized gain of non-derivative net investment hedge into earnings	1,851	0	1,851	0
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative asset, fair value	8,243		8,243
Net liability of derivative	(391)		(391)
Interest expense	273	274	812	905
Amounts reclassified from OCI			1,883
Interest expense to be recognized			1,837
Remaining AOCI balance related to swap to be reclassified in the next twelve months	1,087		1,087
Net Investment Hedge in GBP-denominated Investments [Member]
Derivative [Line Items]
Net liability of derivative	(20,097)		(20,097)
Reclassification of unrealized gain of non-derivative net investment hedge into earnings			1,851
Net gain (loss) on hedge ineffectiveness	$ 891	$ (109)	$ (4,228)	$ (175)
Designated as Hedging Instrument [Member] | Forward Starting Swap [Member]
Derivative [Line Items]
Number of derivative instruments | instrument	1		1

Shareholders' Equity (Deficit74

Shareholders' Equity (Deficit) of the Company (Narrative) (Details)	1 Months Ended					3 Months Ended	9 Months Ended
	Sep. 30, 2017$ / sharesshares	Apr. 30, 2017USD ($)$ / sharesshares	Dec. 31, 2016$ / sharesshares	Jul. 31, 2016USD ($)	Jun. 30, 2016shares	Sep. 30, 2017USD ($)$ / sharesshares	Sep. 30, 2017USD ($)$ / sharesshares	Sep. 30, 2016USD ($)	Feb. 29, 2016USD ($)	Mar. 18, 2014USD ($)
Class of Stock [Line Items]
Capital units, authorized (in shares)	500,000,000		500,000,000			500,000,000	500,000,000
Common stock, par value (in usd per share) | $ / shares	$ 0.01		$ 0.01			$ 0.01	$ 0.01
Capital stock, par value (in usd per share) | $ / shares			$ 0.01
Common stock, shares authorized (in shares)	490,000,000		490,000,000			490,000,000	490,000,000
Preferred stock, shares authorized (in shares)	10,000,000		10,000,000			10,000,000	10,000,000
Preferred stock, shares outstanding (in shares)	3,500,000					3,500,000	3,500,000
Common stock, shares issued (in shares)	160,669,468		140,647,971			160,669,468	160,669,468
Sales price (in usd per share) | $ / shares		$ 27.60
Proceeds from sale of common shares | $		$ 274,234,000					$ 410,736,000	$ 0
Stock split conversion ratio			0.3333
ESPP shares authorized (in shares)	250,000					250,000	250,000
ESPP purchase discount percent	85.00%					85.00%	85.00%
Shares registered for DRIP (in shares)					3,333,333
Dividend reinvestment program proceeds (in shares)							5,410
Shares available for issuance under DRIP (in shares)	3,327,226					3,327,226	3,327,226
Authorized repurchase amount | $									$ 100,000,000
At-the-market offering | $				$ 375,000,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	3,500,000		3,500,000			3,500,000	3,500,000
Preferred stock, shares outstanding (in shares)	3,500,000		3,500,000			3,500,000	3,500,000
Preferred stock, shares issued (in shares)	3,500,000		3,500,000			3,500,000	3,500,000
IPO [Member]
Class of Stock [Line Items]
Shares issued in public offering (in shares)		10,350,000
Over-Allotment Option [Member]
Class of Stock [Line Items]
Shares issued in public offering (in shares)		1,350,000
At Market Offering Program [Member]
Class of Stock [Line Items]
Issuance of shares (in shares)						3,488,525	4,219,978
Proceeds from sale of stock | $						$ 103,351,000	$ 123,051,000
Exchangeable Senior Notes 3.75% [Member] | Convertible Debt [Member]
Class of Stock [Line Items]
Shares issued in conversion (in shares)	5,258,420
Face amount | $										$ 115,000,000
Percent of instrument converted	100.00%

Shareholders' Equity (Deficit75

Shareholders' Equity (Deficit) of the Company (Dividends Paid) (Details) - $ / shares	3 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017
Equity [Abstract]
Dividends declared (in usd per share)	$ 0.375	$ 0.375	$ 0.375

Shareholders' Equity (Deficit76

Shareholders' Equity (Deficit) of the Company (Preferred Stock) (Narrative) (Details) - $ / shares	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	3,500,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	3,500,000	3,500,000
Preferred stock, redemption price per share (in usd per share)	$ 25
7.125% Series A Preferred Stock [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock	7.125%
Preferred stock, dividend rate (in usd per share)	$ 1.78125

Shareholders' Equity (Deficit77

Shareholders' Equity (Deficit) of the Company (Equity Plan Summaries and Earnings Per Share) (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2017	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Outside Interests in Operating Partnership [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive securities (in shares)			1,352,609		849,338
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted shares outstanding (in shares)	352,378		352,378		352,378		318,807
2016 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)	2,734,009		2,734,009		2,734,009
LTIP units issued under plan (in shares)		596,460
Aggregate fair value of units issued		$ 7,800
Grants in period (in shares)					1,037,759
Shares vesting percentage					66.60%
Share-based compensation expense			$ 655	$ 614	$ 2,227	$ 1,701
2016 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense, not yet recognized	$ 4,419		4,419		$ 4,419
Share based compensation expense, not yet recognized, period of recognition					29 months
Outperformance Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			1,158	$ 488	$ 3,284	$ 1,464
Share based compensation expense, not yet recognized	$ 12,537		$ 12,537		$ 12,537
Share based compensation expense, not yet recognized, period of recognition					41 months
Vesting on June 30, 2020 [Member] | 2016 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		50.00%
Vesting on June 30, 2021 [Member] | 2016 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		50.00%
Exchangeable Senior Notes 3.75% [Member] | Convertible Debt [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of instrument converted	100.00%

Shareholders' Equity (Deficit78

Shareholders' Equity (Deficit) of the Company (Schedule of Calculation of Numerator and Denominator in Earnings Per Share) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator - Income (loss)
Net income (loss) from continuing operations	$ 45,607	$ (3,411)	$ 43,520	$ 14,461
Net income (loss) from discontinued operations	(24)	347	(76)	5,045
Net income (loss) before net gain on disposals	45,583	(3,064)	43,444	19,506
Net gain on disposals	4,879	2,336	24,258	2,336
Gain on sale of European unconsolidated equity investment interests held with a related party	0	0	0	5,341
Net Income (loss)	50,462	(728)	67,702	27,183
Net income attributable to noncontrolling interest	(333)	(221)	(374)	(152)
Less: Nonforfeitable dividends allocated to participating shareholders	(191)	(196)	(766)	(596)
Less: Preferred share dividends	(1,559)	(1,559)	(4,676)	(4,676)
Net income (loss) available to common shares outstanding - basic	48,379	(2,704)	61,886	21,759
Plus: Interest expense on Exchangeable Senior Notes	1,462	0	0	0
Net income (loss) available to common shares outstanding - diluted	$ 49,841	$ (2,704)	$ 61,886	$ 21,759
Denominator – Weighted average shares
Weighted average basic shares outstanding (in shares)	152,619,352	140,257,503	147,399,457	141,180,822
Effect of dilutive securities
Unvested non-participating share based payment awards (in shares)	15,052	0	12,709	137,803
Option (in shares)	21,015	0	18,716	13,802
Outside interests in the Operating Partnership (in shares)	0	0	0	399,771
Exchangeable Senior Notes (in shares)	4,851,794	0	0	655,511
Diluted shares (in shares)	157,507,213	140,257,503	147,430,882	142,387,709

Shareholders' Equity (Deficit79

Shareholders' Equity (Deficit) of the Company (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Equity [Abstract]
Net unrealized gain (loss) on derivative securities	$ 4,205	$ (440)
Net unrealized gain on debt instruments	1,497	3,699
Foreign currency translation adjustments:
Net gain on non-derivative net investment hedges	288	4,516
Other foreign currency translation adjustments	(5,826)	(13,045)
Reclassification of swap gain into interest expense	1,954	1,142
Total accumulated other comprehensive income (loss)	2,118	(4,128)
Write-off on non-derivative net investment hedge	$ 1,851	$ 652

Partners' Capital of the Oper80

Partners' Capital of the Operating Partnership (Narrative) (Details) - GPT Operating Partnership LP [Member]	Sep. 30, 2017shares
Limited Partners' Capital Account [Line Items]
Partnership units (in units)	160,324,288
Ownership interest in Operating Partnership	98.08%
Ownership percentage by noncontrolling owners	1.92%
Noncontrolling Interest [Member]
Limited Partners' Capital Account [Line Items]
Partnership units (in units)	3,131,636

Partners' Capital of the Oper81

Partners' Capital of the Operating Partnership (Calculation of Earnings Per Share) (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Sep. 30, 2017USD ($)shares	Sep. 30, 2016USD ($)shares	Sep. 30, 2017USD ($)shares	Sep. 30, 2016USD ($)shares
Numerator - Income (loss)
Net income (loss) from continuing operations		$ 45,607	$ (3,411)	$ 43,520	$ 14,461
Net income (loss) from discontinued operations		(24)	347	(76)	5,045
Net income (loss) before net gain on disposals		45,583	(3,064)	43,444	19,506
Net gain on disposals		4,879	2,336	24,258	2,336
Gain on sale of European unconsolidated equity investment interests held with a related party		0	0	0	5,341
Net Income (loss)		50,462	(728)	67,702	27,183
Less: Nonforfeitable dividends allocated to participating unitholders		(191)	(196)	(766)	(596)
Less: Preferred unit distributions		(1,559)	(1,559)	(4,676)	(4,676)
Plus: Interest expense on Exchangeable Senior Notes		$ 1,462	$ 0	$ 0	$ 0
Effect of dilutive securities
Unvested non-participating unit based payment awards (in units) | shares		15,052	0	12,709	137,803
Option (in units) | shares		21,015	0	18,716	13,802
Exchangeable Senior Notes (in units) | shares		4,851,794	0	0	655,511
Stock split conversion ratio	0.3333
GPT Operating Partnership LP [Member]
Numerator - Income (loss)
Net income (loss) from continuing operations		$ 45,607	$ (3,411)	$ 43,520	$ 14,461
Net income (loss) from discontinued operations		(24)	347	(76)	5,045
Net income (loss) before net gain on disposals		45,583	(3,064)	43,444	19,506
Net gain on disposals		4,879	2,336	24,258	2,336
Gain on sale of European unconsolidated equity investment interests held with a related party		0	0	0	5,341
Net Income (loss)		50,462	(728)	67,702	27,183
Less: Net (gain) loss attributable to noncontrolling interest in other partnerships		97	(229)	114	(90)
Less: Nonforfeitable dividends allocated to participating unitholders		(191)	(196)	(766)	(596)
Less: Preferred unit distributions		(1,559)	(1,559)	(4,676)	(4,676)
Net income (loss) available to common units outstanding - basic		48,809	(2,712)	62,374	21,821
Plus: Interest expense on Exchangeable Senior Notes		1,462	0	0	0
Net income available to common unitholders		$ 50,271	$ (2,712)	$ 62,374	$ 21,821
Denominator – Weighted average shares
Weighted average basic units outstanding (in units) | shares		153,971,961	140,596,612	148,248,795	141,580,593
Effect of dilutive securities
Unvested non-participating unit based payment awards (in units) | shares		15,052	0	12,709	137,803
Option (in units) | shares		21,015	0	18,716	13,802
Exchangeable Senior Notes (in units) | shares		4,851,794	0	0	655,511
Diluted shares (in shares) | shares		158,859,822	140,596,612	148,280,220	142,387,709

Noncontrolling Interests (Narra

Noncontrolling Interests (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended			12 Months Ended
	Sep. 30, 2017USD ($)Propertyshares	Mar. 31, 2017Property	Sep. 30, 2017USD ($)shares	Sep. 30, 2017USD ($)Propertyshares	Sep. 30, 2017USD ($)land_parcelshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Units issued to acquire properties (in units)	2,265,829
Number of Acquisitions		21		74	2
Noncontrolling interest in operating partnership (in usd) | $	$ 75,139		$ 75,139	$ 75,139	$ 75,139	$ 8,643
Noncontrolling interest in other partnerships | $	$ 0		$ 0	$ 0	$ 0	$ (321)
Operating Partnership Units [Member]
Noncontrolling Interest [Line Items]
Shares outstanding (in shares)	2,472,121		2,472,121	2,472,121	2,472,121
Capital shares reserved for future issuance (in shares)	2,472,121		2,472,121	2,472,121	2,472,121
Shares converted			107,547			156,452
Gramercy Europe Asset [Member]
Noncontrolling Interest [Line Items]
Ownership %							50.00%
Long-term Incentive Plan Units [Member]
Noncontrolling Interest [Line Items]
Capital shares reserved for future issuance (in shares)	659,515		659,515	659,515	659,515
Shares vested (in shares)			659,515
GPT Operating Partnership LP [Member]
Noncontrolling Interest [Line Items]
Ownership percentage by noncontrolling owners	1.92%		1.92%	1.92%	1.92%
Noncontrolling interest in operating partnership (in usd) | $	$ 75,139		$ 75,139	$ 75,139	$ 75,139	$ 8,643
Acquired By Issuance of OP Units [Member]
Noncontrolling Interest [Line Items]
Number of Acquisitions | Property	6

Noncontrolling Interests (Nonco

Noncontrolling Interests (Noncontrolling Interest in the Operating Partnership) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance at beginning of period	$ 8,643
Issuance of noncontrolling interests in the Operating Partnership	68,898
Redemption of noncontrolling interests in the Operating Partnership	(2,987)
Net income attribution	488
Fair value adjustments	1,191
Dividends	(1,094)
Balance at end of period	$ 75,139

Commitments and Contingencies84

Commitments and Contingencies (Narrative) (Details) € in Thousands, $ in Thousands	1 Months Ended
	Jul. 31, 2017	Feb. 28, 2017USD ($)	Sep. 30, 2017USD ($)Property	Sep. 30, 2017EUR (€)Property	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Round Rock [Member]
Commitments And Contingencies [Line Items]
Real Estate Assets					$ 29,605
Commitment amount			$ 46,303
The Company [Member] | Gramercy Europe [Member]
Commitments And Contingencies [Line Items]
Initial equity capital available			55,892	€ 50,000
Minimum [Member]
Commitments And Contingencies [Line Items]
Estimate of possible loss			0
Maximum [Member]
Commitments And Contingencies [Line Items]
Estimate of possible loss			360
Chambers Street Properties [Member]
Commitments And Contingencies [Line Items]
Estimate of possible loss			360
Gramercy European Property Fund [Member]
Commitments And Contingencies [Line Items]
Ownership interest sold	100.00%
Strategic Office Partners [Member]
Commitments And Contingencies [Line Items]
Commitment amount			400,000
Investment in unconsolidated equity investment			36,802			$ 16,027
Strategic Office Partners [Member] | Parent Company [Member]
Commitments And Contingencies [Line Items]
Commitment amount			$ 100,000
Operating expense reimbursement audits [Member] | Settled Litigation [Member]
Commitments And Contingencies [Line Items]
Payments for settlement		$ 3,500
Build-to-suit Property [Member] | Round Rock [Member]
Commitments And Contingencies [Line Items]
Properties obligated to build | Property			3	3

Commitments and Contingencies85

Commitments and Contingencies (Schedule of Future Minimum Rental Payments) (Details) $ in Thousands	Sep. 30, 2017USD ($)
Ground Leases - Operating
October 1 to December 31, 2017, operating	$ 562
2018, operating	2,262
2019, operating	2,295
2020, operating	2,295
2021, operating	2,262
Thereafter, operating	62,839
Total minimum rent expense, operating	72,515
Ground Leases - Capital
October 1 to December 31, 2017, capital	0
2018, capital	1
2019, capital	0
2020, capital	0
2021, capital	0
Thereafter, capital	329
Total minimum rent expense, capital	330
Total
October 1 to December 31, 2017	562
2,018	2,263
2,019	2,295
2,020	2,295
2,021	2,262
Thereafter	63,168
Total	$ 72,845

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ (598)	$ 331	$ (647)	$ 3,734

Supplemental Cash Flow Inform87

Supplemental Cash Flow Information (Non-Cash Activities Recognized in Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Interest paid	$ 62,024	$ 59,700
Income taxes paid	663	2,614
Proceeds from 1031 exchanges from sale of real estate	176,924	617,538
Use of funds from 1031 exchanges for acquisitions of real estate	(176,924)	(460,191)
Non-cash activity:
Fair value adjustment to noncontrolling interest in the Operating Partnership	1,191	2,741
Debt assumed in acquisition of real estate	114,649	(45,958)
Debt transferred in disposition of real estate	(10,456)	(101,432)
Non-cash acquisition of consolidated VIE	24,930	0
Dividend reinvestment plan proceeds	151	0
Distribution of real estate assets from unconsolidated equity investment	0	263,015
Treasury securities transferred in connection with defeasance of notes payable	0	(144,063)
Transfer of defeased note payable	0	124,605
Contribution of real estate assets as investment in unconsolidated equity investments	0	(182,168)
Redemption of units of noncontrolling interest in the Operating Partnership for common shares	(2,987)	(4,159)
Real estate acquired for units of noncontrolling interest in the Operating Partnership	68,898	0
Redemption of Exchangeable Senior Notes for common shares	$ 117,450	$ 0

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) $ / shares in Units, € in Thousands

1 Months Ended

3 Months Ended

9 Months Ended

Nov. 01, 2017ft²shares

Nov. 01, 2017USD ($)ft²

Nov. 01, 2017ft²Property

Nov. 01, 2017ft²encumbered_property

Oct. 31, 2017USD ($)extension$ / shares

Sep. 30, 2017shares

Dec. 31, 2015USD ($)

Sep. 30, 2017Property$ / shares

Jun. 30, 2017$ / shares

Mar. 31, 2017Property$ / shares

Sep. 30, 2016Property

Sep. 30, 2017

Sep. 30, 2017Property

Sep. 30, 2017land_parcel

Sep. 30, 2016Property

Oct. 31, 2017EUR (€)extension

Subsequent Event [Line Items]

Dividends declared (in usd per share) | $ / shares

$ 0.375

$ 0.375

$ 0.375

Number of Acquisitions

21

74

2

Units issued to acquire properties (in units) | shares

2,265,829

Number of real estate properties sold | Property

10

20

Subsequent Event [Member]

Subsequent Event [Line Items]

Dividends declared (in usd per share) | $ / shares

$ 0.375

Dividends declared (in usd per share) | $ / shares

$ 0.44531

7.125% Series A Preferred Stock [Member]

Subsequent Event [Line Items]

Dividend rate on preferred stock

7.125%

Series of Individually Immaterial Business Acquisitions [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Area of real estate property | ft²

587,680

587,680

587,680

587,680

Occupancy rate

100.00%

100.00%

100.00%

100.00%

Real estate acquisitions

$ 106,360,000

Units issued to acquire properties (in units) | shares

1,294,359

Industrial Property [Member] | Series of Individually Immaterial Business Acquisitions [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Number of Acquisitions

3

2

Assumption of debt in acquisitions

$ 66,458,000

Build-to-suit Property [Member]

Subsequent Event [Line Items]

Number of Acquisitions | Property

1

Build-to-suit Property [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Area of real estate property | ft²

432,100

432,100

432,100

432,100

Occupancy rate

100.00%

100.00%

100.00%

100.00%

Disposed by Sale [Member]

Subsequent Event [Line Items]

Number of real estate properties sold | Property

8

25

Disposed by Sale [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Area of real estate property | ft²

78,767

78,767

78,767

78,767

Proceeds from sale of real estate

$ 10,030,000

Disposed by Sale [Member] | Offices [Member]

Subsequent Event [Line Items]

Number of real estate properties sold | Property

2

Disposed by Sale [Member] | Offices [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Number of real estate properties sold | Property

2

7-Year Term Loan [Member] | Capital One [Member] | Term Loans [Member]

Subsequent Event [Line Items]

Term of debt

7 years

Face amount

$ 175,000,000

7-Year Term Loan [Member] | Capital One [Member] | Term Loans [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Term of debt

7 years

Face amount

$ 400,000,000

Swapped fixed rate

3.00%

3.00%

Decrease in basis points

0.34%

Mezzanine Construction Loan Facility [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Maximum borrowing balance

$ 250,000,000

Facility term

5 years

Number of extensions | extension

2

2

Term of extensions

1 year

Outstanding facility balance

$ 15,918,000

Minimum [Member] | Mezzanine Construction Loan Facility [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Interest rate on facility

9.00%

9.00%

Maximum [Member] | Mezzanine Construction Loan Facility [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Interest rate on facility

12.00%

12.00%

European Investment Fund [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Initial capital contributions

$ 310,262,000

€ 262,622

European Investment Fund [Member] | Gramercy Property Trust [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Initial capital contributions

$ 61,654,000

€ 52,187

Uncategorized Items - gpt-20170

Label	Element	Value
GPT Operating Partnership LP [Member] | AOCI Attributable to Parent [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Net Investment Hedges, Net of Tax	gpt_OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonNetInvestmentHedgesNetofTax	$ 1,851,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax	1,362,000
GPT Operating Partnership LP [Member] | Operating Partnership (Including Noncontrolling Interest) [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Net Investment Hedges, Net of Tax	gpt_OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonNetInvestmentHedgesNetofTax	1,851,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax	1,362,000
Goodman Europe Joint Venture [Member] | Corporate Joint Venture [Member]
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	0
Gramercy European Property Fund (excluding legacy Goodman Europe Joint Venture) [Member] | Corporate Joint Venture [Member]
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	0
Europe [Member] | Goodman Europe Joint Venture [Member] | Corporate Joint Venture [Member]
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	0
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	3,276,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	7,907,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	120,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	4,165,000
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	1,590,000
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	631,000
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	121,000
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	3,201,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	6,195,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	18,389,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	303,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	10,581,000
Equity Method Investment, Realized Gain (Loss) on Disposal	us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal	6,458,000
Equity Method Investment, Realized Gain (Loss) on Disposal	us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal	6,458,000
Equity Method Investment, Summarized Financial Information, Acquisition and Related Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationAcquisitionandRelatedExpense	0
Equity Method Investment, Summarized Financial Information, Acquisition and Related Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationAcquisitionandRelatedExpense	4,960,000
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	(11,000)
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	(455,000)
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	0
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	73,000
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	676,000
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	2,372,000
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	33,000
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	1,900,000
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	1,590,000
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	631,000
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	83,000
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	3,131,000
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Extinguishment of Debt	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonExtinguishmentofDebt	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Extinguishment of Debt	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonExtinguishmentofDebt	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Extinguishment of Debt	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonExtinguishmentofDebt	0
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	4,605,000
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	17,758,000
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	182,000
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	7,380,000
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	0
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	0
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	38,000
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	70,000
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	0
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	322,000
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	(444,000)
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	4,000
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	159,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	653,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	2,519,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	29,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	1,315,000
Europe [Member] | Goodman Europe Joint Venture [Member] | Continuing Operations [Member] | Corporate Joint Venture [Member]
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	333,000
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	11,000
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	6,462,000
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	6,544,000
Europe [Member] | Gramercy European Property Fund (excluding legacy Goodman Europe Joint Venture) [Member] | Corporate Joint Venture [Member]
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	230,392,000
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Disposals	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDisposals	230,392,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	2,800,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	7,632,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	237,000
Equity Method Investment Summarized Financial Information Depreciation and Amortization	gpt_EquityMethodInvestmentSummarizedFinancialInformationDepreciationandAmortization	10,032,000
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	(369,000)
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	(260,000)
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	1,492,000
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationGrossProfitLoss	4,269,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	7,329,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	18,270,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	593,000
Equity Method Investment, Summarized Financial Information, Revenue	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationRevenue	22,190,000
Equity Method Investment, Realized Gain (Loss) on Disposal	us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal	(5,103,000)
Equity Method Investment, Realized Gain (Loss) on Disposal	us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal	(5,103,000)
Equity Method Investment, Summarized Financial Information, Acquisition and Related Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationAcquisitionandRelatedExpense	2,141,000
Equity Method Investment, Summarized Financial Information, Acquisition and Related Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationAcquisitionandRelatedExpense	4,678,000
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	0
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	0
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	0
Income (Loss) from Equity Method Investments, Adjustments for REIT Basis	gpt_IncomeLossfromEquityMethodInvestmentsAdjustmentsforREITBasis	0
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	1,619,000
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	3,188,000
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	(1,288,000)
Equity Method Investment, Summarized Financial Information, Operating Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationOperatingExpenses	4,465,000
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	(1,777,000)
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	(7,564,000)
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	231,794,000
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss	236,563,000
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Extinguishment of Debt	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonExtinguishmentofDebt	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Extinguishment of Debt	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonExtinguishmentofDebt	0
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Extinguishment of Debt	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonExtinguishmentofDebt	0
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	7,698,000
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	18,530,000
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	(899,000)
Equity Method Investment Summarized Financial Information Expenses	gpt_EquityMethodInvestmentSummarizedFinancialInformationExpenses	17,921,000
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	284,000
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	876,000
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	68,000
Equity Method Investment, Summarized Financial Information, Income Tax Expense (Benefit)	gpt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTaxExpenseBenefit	346,000
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	(1,124,000)
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	(6,428,000)
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	(22,000)
Equity Method Investment, Summarized Financial Information, Gain (Loss) on Derivatives	gpt_EquityMethodInvestmentSummarizedFinancialInformationGainLossonDerivatives	2,248,000
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	(252,000)
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	(1,386,000)
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	32,927,000
Income Loss From Equity Method Investments Prior To Adjustments For Reit Basis	gpt_IncomeLossFromEquityMethodInvestmentsPriorToAdjustmentsForReitBasis	33,812,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	1,138,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	3,032,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	152,000
Equity Method Investment Summarized Financial Information Interest Expense	gpt_EquityMethodInvestmentSummarizedFinancialInformationInterestExpense	3,424,000
Europe [Member] | Gramercy European Property Fund (excluding legacy Goodman Europe Joint Venture) [Member] | Continuing Operations [Member] | Corporate Joint Venture [Member]
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	(252,000)
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	(1,386,000)
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	27,824,000
Income (Loss) from Equity Method Investments	us-gaap_IncomeLossFromEquityMethodInvestments	28,709,000
Parent [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Net Investment Hedges, Net of Tax	gpt_OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonNetInvestmentHedgesNetofTax	1,851,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax	1,362,000
AOCI Attributable to Parent [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Net Investment Hedges, Net of Tax	gpt_OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonNetInvestmentHedgesNetofTax	1,851,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax	$ 1,362,000