Peakstone Realty Trust (PKST) S-4/A 15 Jan 19 Registration of securities issued in business combination transactions (amended) Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Griffin Capital Essential Asset REIT II, Inc.
Entity Central Index Key	1,600,626
Document Type	S4
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Small Business	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 33,786	$ 33,164	$ 49,340
Restricted cash	14,642	12,886	14,221
Real estate:
Land	122,482	122,482	117,569
Building and improvements	819,079	815,721	787,999
Tenant origination and absorption cost	240,364	240,364	227,407
Construction in progress	132	299	80
Total real estate	1,182,057	1,178,866	1,133,055
Less: accumulated depreciation and amortization	(117,288)	(83,905)	(39,955)
Total real estate, net	1,064,769	1,094,961	1,093,100
Intangible assets, net	3,016	3,294	3,528
Due from affiliates	1,128	686	0
Deferred rent	29,851	22,733	5,424
Other assets	6,862	12,224	18,862
Total assets	1,154,054	1,179,948	1,184,475
LIABILITIES AND EQUITY
Debt, net	481,573	481,848	456,472
Long-term Line of Credit		355,561	330,272
Notes Payable		126,287	126,200
Restricted reserves	13,310	13,368	55,797
Distributions payable	1,772	1,689	1,494
Due to affiliates	18,988	16,896	22,481
Below market leases, net	47,506	51,295	55,319
Accrued expenses and other liabilities	21,765	19,903	21,527
Total liabilities	584,914	584,999	613,090
Commitments and contingencies
Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests	37,401	32,405	16,930
Stockholders’ equity:
Common Stock, $0.001 par value; 700,000,000 shares authorized; 166,253,534 and 170,906,111 shares outstanding, as of September 30, 2018 and December 31, 2017, respectively	77	76	71
Additional paid-in capital	657,756	656,705	615,653
Cumulative distributions	(114,510)	(82,590)	(38,406)
Accumulated earnings	(13,102)	(12,672)	(23,788)
Accumulated other comprehensive income	310	949	841
Total stockholders’ equity	530,531	562,468	554,371
Stockholders' Equity Attributable to Noncontrolling Interest	1,208	76	84
Total equity	531,739	562,544	554,455
Total liabilities and equity	1,154,054	1,179,948	1,184,475
Griffin Capital Essential Asset REIT, Inc. [Member]
ASSETS
Cash and cash equivalents	47,946	40,735	43,442
Restricted cash	22,365	174,132	13,420
Real estate:
Land	352,419	341,432	374,557
Building and improvements	2,172,884	2,022,372	2,102,785
Tenant origination and absorption cost	532,207	494,871	541,646
Construction in progress	20,251	7,078	5,401
Total real estate	3,077,761	2,865,753	3,024,389
Less: accumulated depreciation and amortization	(512,929)	(425,958)	(338,552)
Total real estate, net	2,564,832	2,439,795	2,685,837
Intangible assets, net	11,671	16,123	26,876
Real estate assets and other assets held for sale, net	2,711	2,959
Investments in unconsolidated entities	33,360	37,114	46,313
Intangible assets, net	13,796	18,269	29,048
Deferred rent	56,801	46,591	43,900
Deferred leasing costs, net	25,310	19,755	14,139
Other assets	29,510	24,060	18,704
Total assets	2,796,631	2,803,410	2,894,803
LIABILITIES AND EQUITY
Debt, net	1,354,350	1,386,084	1,447,535
Mortgage Payable and Premium		666,920	343,461
Senior Notes		711,697	710,489
Long-term Line of Credit		7,467	393,585
Restricted reserves	8,674	8,701	9,437
Redemptions payable	6,653	20,382	11,565
Distributions payable	7,527	6,409	6,377
Due to affiliates	4,018	3,535	2,719
Below market leases, net	24,703	23,581	31,636
Liabilities of real estate assets held for sale	293	537
Accrued expenses and other liabilities	74,934	63,606	65,005
Total liabilities	1,481,152	1,512,835	1,574,274
Commitments and contingencies
Noncontrolling interests subject to redemption; 531,000 units eligible towards redemption as of September 30, 2018 and December 31, 2017	4,887	4,887	4,887
Common stock subject to redemption and perpetual convertible preferred stock		33,877	92,058
Stockholders’ equity:
Common Stock, $0.001 par value; 700,000,000 shares authorized; 166,253,534 and 170,906,111 shares outstanding, as of September 30, 2018 and December 31, 2017, respectively	166	171	176
Additional paid-in capital	1,557,009	1,561,694	1,561,516
Cumulative distributions	(541,913)	(454,526)	(333,829)
Accumulated earnings	127,511	110,907	(29,750)
Accumulated other comprehensive income	9,736	2,460	(4,643)
Total stockholders’ equity	1,152,509	1,220,706	1,193,470
Stockholders' Equity Attributable to Noncontrolling Interest	28,723	31,105
Noncontrolling interests	28,723	31,105	30,114
Total equity	1,181,232	1,251,811	1,223,584
Total liabilities and equity	2,796,631	2,803,410	$ 2,894,803
Griffin Capital Essential Asset REIT, Inc. [Member] | Common stock subject to redemption
LIABILITIES AND EQUITY
Common stock subject to redemption and perpetual convertible preferred stock	4,360	33,877
Griffin Capital Essential Asset REIT, Inc. [Member] | Perpetual convertible preferred shares
LIABILITIES AND EQUITY
Common stock subject to redemption and perpetual convertible preferred stock	$ 125,000	$ 0

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Common Stock, par value (in usd per share)	$ 0.001	$ 0.001
Common Stock, shares authorized (in shares)	800,000,000	700,000,000
Number of shares outstanding (in shares)	77,175,283	70,939,647
Griffin Capital Essential Asset REIT, Inc. [Member]
Noncontrolling interest, units eligible towards redemption (in shares)	531,000	531,000
Common Stock, par value (in usd per share)	$ 0.001	$ 0.001
Common Stock, shares authorized (in shares)	700,000,000	700,000,000
Number of shares outstanding (in shares)	170,906,111	176,032,871

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Rental income	$ 21,928	$ 22,926	$ 65,854	$ 67,211	$ 89,797	$ 51,403	$ 21,216
Property expense recoveries	4,785	4,423	13,945	12,671	17,584	11,409	3,933
Total revenue	26,713	27,349	79,799	79,882	107,381	62,812	25,149
Expenses:
Asset management fees to affiliates	0	2,485	0	8,026	8,027	6,413	2,624
Property management fees to affiliates	456	452	1,365	1,347	1,799	1,052	333
Advisory fees to affiliates	2,346	273	6,970	273	2,550	0	0
Property operating expense	1,866	1,787	5,598	4,886	6,724	4,428	1,317
Property tax expense	2,449	2,511	7,521	7,244	10,049	7,046	2,713
Acquisition fees and expenses to non-affiliates					0	1,113	3,058
Performance distribution to affiliates	2,084	213	6,200	213	2,394	0	0
Acquisition fees and expenses to affiliates					0	6,176	10,876
General and administrative expenses	775	831	2,446	2,736	3,445	2,804	1,883
Corporate operating expenses to affiliates	806	566	2,168	1,679	2,336	1,622	1,937
Depreciation and amortization	11,252	11,236	33,383	32,710	43,950	27,894	12,061
Total expenses	22,034	20,354	65,651	59,114	81,274	58,548	36,802
Income before other income and (expenses)	4,679	6,995	14,148	20,768	26,107	4,264	(11,653)
Other income (expenses):
Interest expense	(5,464)	(3,997)	(14,775)	(11,445)	(15,519)	(10,384)	(4,851)
Other income, net	28	101	196	265	531	13	0
Net income	(757)	3,099	(431)	9,588	11,119	(6,107)	(16,504)
Preferred units redemption premium					0	0	(375)
Net (income) attributable to noncontrolling interests	1	(1)	1	(3)	(3)	3	30
Distributions to redeemable noncontrolling interests attributable to common stockholders					0	0	(398)
Net income attributable to common stockholders	$ (756)	$ 3,098	$ (430)	$ 9,585	$ 11,116	$ (6,104)	$ (17,247)
Net income attributable to common stockholders per share, basic and diluted (in usd per share)	$ (0.01)	$ 0.04	$ (0.01)	$ 0.13	$ 0.15	$ (0.12)	$ (1.19)
Weighted average number of common shares outstanding, basic and diluted (in shares)	78,034,852	76,157,963	77,594,234	75,441,620	75,799,415	50,712,589	14,479,960
Distributions declared per common share (in usd per share)	$ 0.14	$ 0.14	$ 0.42	$ 0.42
Griffin Capital Essential Asset REIT, Inc. [Member]
Revenue:
Rental income	$ 66,028	$ 66,437	$ 187,601	$ 197,647	$ 257,465	$ 267,654	$ 226,174
Lease termination income	84	0	9,090	12,845	14,604	1,211	8,974
Property expense recoveries	18,929	18,695	54,740	54,120	74,421	75,409	57,705
Total revenue	85,041	85,132	251,431	264,612	346,490	344,274	292,853
Expenses:
Asset management fees to affiliates	6,015	5,921	17,670	17,786	23,499	23,530	19,389
Property management fees to affiliates	2,503	2,453	7,049	7,519	9,782	9,740	7,622
Property operating expense	13,055	13,507	36,060	37,261	50,349	50,946	40,682
Property tax expense	11,301	10,916	33,460	33,465	44,980	45,789	34,733
Acquisition fees and expenses to non-affiliates					0	541	2,730
Acquisition fees and expenses to affiliates					0	1,239	32,245
General and administrative expenses	2,111	1,030	5,042	5,274	7,891	6,584	5,987
Corporate operating expenses to affiliates	948	676	2,630	1,983	2,652	1,525	1,608
Depreciation and amortization	30,096	28,235	89,258	88,783	116,583	130,849	112,748
Impairment provision	0	0	0	5,675	8,460	0	0
Total expenses	66,029	62,738	191,169	197,746	264,196	270,743	257,744
Income before other income and (expenses)	19,012	22,394	60,262	66,866	82,294	73,531	35,109
Other income (expenses):
Interest expense	(14,161)	(12,692)	(41,251)	(37,232)	(51,015)	(48,850)	(33,402)
Other income	57	260	217	495	537	2,848	1,576
Loss from investment in unconsolidated entities	(579)	(517)	(1,617)	(1,511)	(2,065)	(1,640)	(1,475)
Gain on acquisition of unconsolidated entity					0	666	0
Gain from disposition of assets	0	0	1,158	4,293	116,382	0	13,813
Net income	4,329	9,445	18,769	32,911	146,133	26,555	15,621
Preferred units redemption premium					0	0	(9,905)
Distributions to redeemable preferred unit holders					0	0	(9,245)
Distributions to redeemable preferred shareholders	(1,228)	0	(1,228)	0
Net (income) attributable to noncontrolling interests	(157)	(326)	(671)	(1,134)	(5,120)	(912)	138
Net income attributable to controlling interest	2,944	9,119	16,870	31,777	141,013	25,643	(3,391)
Distributions to redeemable noncontrolling interests attributable to common stockholders	(90)	(90)	(266)	(266)	(356)	(358)	(359)
Net income attributable to common stockholders	$ 2,854	$ 9,029	$ 16,604	$ 31,511	$ 140,657	$ 25,285	$ (3,750)
Net income attributable to common stockholders per share, basic and diluted (in usd per share)	$ 0.02	$ 0.05	$ 0.10	$ 0.18	$ 0.81	$ 0.14	$ (0.02)
Weighted average number of common shares outstanding, basic and diluted (in shares)	165,964,543	173,661,904	168,357,361	174,787,551	173,923,077	175,481,629	155,059,231
Distributions declared per common share (in usd per share)	$ 0.17	$ 0.17	$ 0.51	$ 0.51

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ (757,000)	$ 3,099,000	$ (431,000)	$ 9,588,000	$ 11,119,000	$ (6,107,000)	$ (16,504,000)
Other comprehensive (loss) income:
Change in fair value of swap agreement	(348,000)	(87,000)	(641,000)	(17,000)	108,000	841,000	0
Total comprehensive income	(1,105,000)	3,012,000	(1,072,000)	9,571,000	11,227,000	(5,266,000)	(16,504,000)
Preferred units redemption premium					0	0	(375,000)
Distributions to redeemable noncontrolling interests attributable to common stockholders					0	0	(398,000)
Comprehensive (income) attributable to noncontrolling interests	2,000	(1,000)	3,000	(3,000)	(3,000)	3,000	30,000
Comprehensive income attributable to common stockholders	(1,103,000)	3,011,000	(1,069,000)	9,568,000	11,224,000	(5,263,000)	(17,247,000)
Griffin Capital Essential Asset REIT, Inc. [Member]
Net income	4,329,000	9,445,000	18,769,000	32,911,000	146,133,000	26,555,000	15,621,000
Other comprehensive (loss) income:
Equity in other comprehensive (loss) income of unconsolidated joint venture	(12,000)	311,000	224,000	489,000	465,000	241,000	(189,000)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax					6,891,000	2,033,000	(6,371,000)
Change in fair value of swap agreements	3,297,000	748,000	7,276,000	3,471,000
Total comprehensive income	7,614,000	10,504,000	26,269,000	36,871,000	153,489,000	28,829,000	9,061,000
Distributions to redeemable preferred unit holders					0	0	(9,245,000)
Preferred units redemption premium					0	0	(9,905,000)
Distributions to redeemable preferred shareholders	(1,228,000)	0	(1,228,000)	0
Distributions to redeemable noncontrolling interests attributable to common stockholders	(90,000)	(90,000)	(266,000)	(266,000)	(356,000)	(358,000)	(359,000)
Comprehensive (income) attributable to noncontrolling interests	(232,000)	(361,000)	(895,000)	(1,268,000)	(5,373,000)	(990,000)	282,000
Comprehensive income attributable to common stockholders	$ 6,064,000	$ 10,053,000	$ 23,880,000	$ 35,337,000	$ 147,760,000	$ 27,481,000	$ (10,166,000)

Consolidated Statements of Equi

Consolidated Statements of Equity (Unaudited) - USD ($)	Total	Total Stockholders’ Equity	Common Stock	Additional Paid-In Capital	Cumulative Distributions	Accumulated (Deficit) Earnings	Accumulated Other Comprehensive Loss	Non- controlling Interests	Griffin Capital Essential Asset REIT, Inc. [Member]	Griffin Capital Essential Asset REIT, Inc. [Member]Total Stockholders’ Equity	Griffin Capital Essential Asset REIT, Inc. [Member]Common Stock	Griffin Capital Essential Asset REIT, Inc. [Member]Additional Paid-In Capital	Griffin Capital Essential Asset REIT, Inc. [Member]Cumulative Distributions	Griffin Capital Essential Asset REIT, Inc. [Member]Accumulated (Deficit) Earnings	Griffin Capital Essential Asset REIT, Inc. [Member]Accumulated Other Comprehensive Loss	Griffin Capital Essential Asset REIT, Inc. [Member]Non- controlling Interests
BALANCE at Dec. 31, 2014	$ 9,479,000	$ 9,340,000	$ 11,000	$ 9,838,000	$ (72,000)	$ (437,000)	$ 0	$ 139,000	$ 990,985,000	$ 973,507,000	$ 1,326,000	$ 1,128,318,000	$ (104,429,000)	$ (51,285,000)	$ (423,000)	$ 17,478,000
BALANCE (in shares) at Dec. 31, 2014			1,133,773								129,763,016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for SOR Merger									433,667,000	433,667,000	$ 42,000	433,625,000
Issuance of common stock for SOR Merger (shares)											41,764,968
Adjustment to par value									0	0	$ (1,217,000)	1,217,000
Adjustments to redemption value of redeemable noncontrolling interest									(10,473,000)	(10,473,000)		(10,473,000)
Gross proceeds from issuance of common stock	268,973,000	268,973,000	$ 16,000	268,957,000
Gross proceeds from issuance of common stock (shares)			26,897,208
Discount on issuance of common stock	(997,000)	(997,000)		(997,000)
Deferred equity compensation									12,000	12,000		12,000
Deferred equity compensation (in shares)											667
Distributions to common stockholders	(3,173,000)	(3,173,000)			(3,173,000)				(55,045,000)	(55,045,000)			(55,045,000)
Issuance of shares for distribution reinvestment plan			$ 2,000	4,535,000	(4,537,000)				52,557,000		$ 28,000	52,529,000	(52,557,000)
Issuance of shares for distribution reinvestment plan (in shares)			477,638								5,053,669
Issuance of stock dividend (in shares)			47,551
Issuance of stock dividend				476,000	(476,000)
Repurchase of common stock									(13,819,000)	(13,819,000)	$ (4,000)	(13,815,000)
Repurchase of common stock (in shares)											(1,397,801)
Additions to noncontrolling interests subject to redemption	(375,000)	(375,000)			(375,000)
Distributions to noncontrolling interests								(11,000)	(3,150,000)							(3,150,000)
Issuance of limited partnership units									7,282,000							7,282,000
Distributions to noncontrolling interests subject to redemption									(10,000)							(10,000)
Offering costs on preferred shares	(27,514,000)	(27,514,000)		(27,514,000)					(62,000)	(62,000)		(62,000)
Additions to common stock subject to redemption	(4,538,000)	(4,538,000)		(4,538,000)					(35,232,000)	(35,232,000)		(35,232,000)
Noncontrolling Interest, Increase for Offering Costs and Distributions to Noncontrolling Interest Holders	364,000	375,000			375,000			(11,000)	5,380,000	5,380,000		5,380,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Distributions to Redeemable Preferred Units, and Preferred Unit Redemption Charges	(17,277,000)	(17,247,000)				(17,247,000)		(30,000)
Net income									(3,888,000)	(3,750,000)				(3,750,000)		(138,000)
Other comprehensive income									(6,560,000)	(6,416,000)					(6,416,000)	(144,000)
BALANCE at Dec. 31, 2015	224,942,000	224,844,000	$ 29,000	250,757,000	(8,258,000)	(17,684,000)	0	98,000	1,309,087,000	1,287,769,000	$ 175,000	1,561,499,000	(212,031,000)	(55,035,000)	(6,839,000)	21,318,000
BALANCE (in shares) at Dec. 31, 2015			28,556,170								175,184,519
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Gross proceeds from issuance of common stock	406,463,000	406,463,000	$ 40,000	406,423,000
Gross proceeds from issuance of common stock (shares)			40,700,406
Discount on issuance of common stock	(696,000)	(696,000)		(696,000)
Deferred equity compensation									18,000	18,000		18,000
Deferred equity compensation (in shares)											1,333
Distributions to common stockholders	(12,479,000)	(12,479,000)			(12,479,000)				(69,624,000)	(69,624,000)			(69,624,000)
Issuance of shares for distribution reinvestment plan			$ 2,000	15,157,000	(15,159,000)				52,174,000		$ 5,000	52,169,000	(52,174,000)
Issuance of shares for distribution reinvestment plan (in shares)			1,599,355								5,011,974
Issuance of stock dividend (in shares)			251,158
Issuance of stock dividend				2,510,000	(2,510,000)
Repurchase of common stock									(41,443,000)	(41,443,000)	$ (4,000)	(41,439,000)
Repurchase of common stock (in shares)											(4,164,955)
Repurchase of common stock	(1,627,000)	(1,627,000)		(1,627,000)
Repurchase of common stock (in shares)			(167,442)
Distributions to noncontrolling interests	(11,000)							(11,000)	(4,124,000)							(4,124,000)
Issuance of limited partnership units									11,941,000							11,941,000
Distributions to noncontrolling interests subject to redemption									(11,000)							(11,000)
Offering costs on preferred shares	(43,340,000)	(43,340,000)		(43,340,000)
Additions to common stock subject to redemption	(13,531,000)	(13,531,000)		(13,531,000)					(10,731,000)	(10,731,000)		(10,731,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Distributions to Redeemable Preferred Units, and Preferred Unit Redemption Charges	(6,107,000)	(6,104,000)				(6,104,000)		(3,000)
Net income									26,197,000	25,285,000				25,285,000		912,000
Other comprehensive income	841,000	841,000					841,000		2,274,000	2,196,000					2,196,000	78,000
BALANCE at Dec. 31, 2016	$ 554,455,000	554,371,000	$ 71,000	615,653,000	(38,406,000)	(23,788,000)	841,000	84,000	$ 1,223,584,000	1,193,470,000	$ 176,000	1,561,516,000	(333,829,000)	(29,750,000)	(4,643,000)	30,114,000
BALANCE (in shares) at Dec. 31, 2016	70,939,647		70,939,647						176,032,871		176,032,871
BALANCE at Dec. 31, 2015	$ 224,942,000	224,844,000	$ 29,000	250,757,000	(8,258,000)	(17,684,000)	0	98,000	$ 1,309,087,000	1,287,769,000	$ 175,000	1,561,499,000	(212,031,000)	(55,035,000)	(6,839,000)	21,318,000
BALANCE (in shares) at Dec. 31, 2015			28,556,170								175,184,519
BALANCE at Dec. 31, 2017	$ 562,544,000	562,468,000	$ 76,000	656,705,000	(82,590,000)	(12,672,000)	949,000	76,000	$ 1,251,811,000	1,220,706,000	$ 171,000	1,561,694,000	(454,526,000)	110,907,000	2,460,000	31,105,000
BALANCE (in shares) at Dec. 31, 2017	77,175,283		77,175,283						170,906,111		170,906,111
BALANCE at Dec. 31, 2016	$ 554,455,000	554,371,000	$ 71,000	615,653,000	(38,406,000)	(23,788,000)	841,000	84,000	$ 1,223,584,000	1,193,470,000	$ 176,000	1,561,516,000	(333,829,000)	(29,750,000)	(4,643,000)	30,114,000
BALANCE (in shares) at Dec. 31, 2016	70,939,647		70,939,647						176,032,871		176,032,871
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Gross proceeds from issuance of common stock	$ 41,826,000	41,826,000	$ 4,000	41,822,000
Gross proceeds from issuance of common stock (shares)			4,205,673
Discount on issuance of common stock	(16,000)	(16,000)		(16,000)
Deferred equity compensation									$ 173,000	173,000		173,000
Deferred equity compensation (in shares)											13,000
Distributions to common stockholders	(19,427,000)	(19,427,000)			(19,427,000)				(71,156,000)	(71,156,000)			(71,156,000)
Issuance of shares for distribution reinvestment plan		0	$ 2,000	22,206,000	(22,208,000)				49,541,000	0	$ 5,000	49,536,000	(49,541,000)
Issuance of shares for distribution reinvestment plan (in shares)			2,358,188								4,791,485
Issuance of stock dividend (in shares)			269,774
Issuance of stock dividend	0	0	$ 0	2,549,000	(2,549,000)
Repurchase of common stock									(98,906,000)	(98,906,000)	$ (10,000)	(98,896,000)
Repurchase of common stock (in shares)											(9,931,245)
Stock-based compensation	292,000	292,000		292,000
Stock-based compensation (in shares)			25,500
Repurchase of common stock	(5,742,000)	(5,742,000)	$ (1,000)	(5,741,000)
Repurchase of common stock (in shares)			(623,499)
Reduction of common stock subject to redemption									49,365,000	49,365,000		49,365,000
Issuance of limited partnership units								0
Distributions to noncontrolling interests	(11,000)							(11,000)	(4,369,000)	0						(4,369,000)
Issuance of limited partnership units																0
Distributions to noncontrolling interests subject to redemption									(13,000)	0						(13,000)
Offering costs on preferred shares	(3,593,000)	(3,593,000)		(3,593,000)
Additions to common stock subject to redemption	(16,467,000)	(16,467,000)		(16,467,000)					49,365,000	49,365,000		49,365,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Distributions to Redeemable Preferred Units, and Preferred Unit Redemption Charges	11,119,000	11,116,000				11,116,000		3,000
Net income									145,777,000	140,657,000				140,657,000		5,120,000
Other comprehensive income	108,000	108,000					108,000		7,356,000	7,103,000					7,103,000	253,000
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest								0
BALANCE at Dec. 31, 2017	$ 562,544,000	562,468,000	$ 76,000	656,705,000	(82,590,000)	(12,672,000)	949,000	76,000	$ 1,251,811,000	1,220,706,000	$ 171,000	1,561,694,000	(454,526,000)	110,907,000	2,460,000	31,105,000
BALANCE (in shares) at Dec. 31, 2017	77,175,283		77,175,283						170,906,111		170,906,111
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Gross proceeds from issuance of common stock	$ 7,430,000	7,430,000	$ 1,000	7,429,000
Gross proceeds from issuance of common stock (shares)			762,537
Changes in redeemable common stock	(5,292,000)	(5,292,000)		(5,292,000)
Discount on issuance of common stock	(1,000)	(1,000)		(1,000)
Deferred equity compensation									$ 37,000	37,000		37,000
Deferred equity compensation (in shares)											7,667
Distributions to common stockholders	(15,498,000)	(15,498,000)			(15,498,000)				(53,720,000)	(53,720,000)			(53,720,000)
Issuance of shares for distribution reinvestment plan	0	0	$ 2,000	16,420,000	(16,422,000)				33,667,000	0	$ 3,000	33,664,000	(33,667,000)
Issuance of shares for distribution reinvestment plan (in shares)			1,712,265								3,353,277
Issuance of stock dividend (in shares)			2
Repurchase of common stock									(76,912,000)	(76,912,000)	$ (8,000)	(76,904,000)
Repurchase of common stock (in shares)											(8,013,521)
Stock-based compensation	44,000	44,000		44,000
Stock-based compensation (in shares)			10,500
Repurchase of common stock	(18,900,000)	(18,900,000)	$ (2,000)	(18,898,000)
Repurchase of common stock (in shares)			(2,000,321)
Reduction of common stock subject to redemption									43,245,000	43,245,000		43,245,000
Issuance of limited partnership units	1,185,000							1,185,000
Distributions to noncontrolling interests	(50,000)							(50,000)	(3,267,000)							(3,267,000)
Distributions to noncontrolling interests subject to redemption									(10,000)							(10,000)
Offering costs on preferred shares	(1,129,000)	(1,129,000)		(1,129,000)					(4,727,000)	(4,727,000)		(4,727,000)
Additions to common stock subject to redemption	2,478,000	2,478,000		2,478,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Distributions to Redeemable Preferred Units, and Preferred Unit Redemption Charges	(431,000)	(430,000)				(430,000)		(1,000)
Net income									17,275,000	16,604,000				16,604,000		671,000
Other comprehensive income	(641,000)	(639,000)					(639,000)	(2,000)	7,500,000	7,276,000				0	7,276,000	224,000
BALANCE at Sep. 30, 2018	$ 531,739,000	$ 530,531,000	$ 77,000	$ 657,756,000	$ (114,510,000)	$ (13,102,000)	$ 310,000	$ 1,208,000	$ 1,181,232,000	$ 1,152,509,000	$ 166,000	$ 1,557,009,000	$ (541,913,000)	$ 127,511,000	$ 9,736,000	$ 28,723,000
BALANCE (in shares) at Sep. 30, 2018	77,660,266		77,660,266						166,253,534		166,253,534

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net income	$ (431)	$ 9,588	$ 11,119	$ (6,107)	$ (16,504)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of building and building improvements	15,284	15,053	20,194	11,630	4,916
Amortization of leasing costs and intangibles, including ground leasehold interests	18,099	17,657	23,756	16,264	7,145
Amortization of above and below market leases	(3,511)	(3,389)	(4,573)	(3,592)	(1,858)
Amortization of deferred financing costs and debt premium	981	826	1,106	1,196	514
Deferred rent	(7,118)	(13,227)	(17,308)	(3,924)	(1,500)
Unrealized loss on interest rate swap	77	60	83	(155)	0
Stock-based compensation	44	267	292	0	0
Performance Distribution Allocation	3,607	0
Change in operating assets and liabilities:
Deferred leasing costs and other assets	1,714	3,730	4,590	(1,040)	(2,065)
Accrued expenses and other liabilities	4,197	(629)	(2,615)	3,094	6,271
Due to affiliates, net	1,749	1,345	3,068	(922)	146
Net cash provided by operating activities	34,692	31,281	39,712	16,444	(2,935)
Investing Activities:
Acquisition of properties, net	0	(44,234)	(44,234)	(538,845)	(479,198)
Restricted reserves	(58)	(20,251)	(42,430)	(3,541)	0
Improvements to real estate			(21)	(40)	0
Payments for construction-in-progress	(440)	(407)	(772)	(80)	0
Proceeds from Deposits on Real Estate Sales	0	250
Real estate acquisition deposits			250	8,700	(6,950)
Net cash (used in) provided by investing activities	(498)	(64,642)	(87,207)	(533,806)	(486,148)
Financing Activities:
Proceeds from borrowings - Revolver Loan	0	14,300	24,300	249,900	286,050
Proceeds from Issuance of Secured Debt	250,000	0
Proceeds from Issuance of Unsecured Debt	113,000	0
Principal payoff of secured indebtedness - Revolver Loan	(357,673)	0	0	(55,000)	(147,492)
Proceeds from Notes Payable			0	0	126,970
Payments for (Proceeds from) Mortgage Deposits			(30)	(1,578)	(2,186)
Proceeds from Issuance of Redeemable Preferred Stock			0	0	73,260
Payments for Repurchase of Redeemable Preferred Stock			0	0	(73,260)
Payments for Preferred Offering Costs			0	0	(375)
Payments of Financing Costs	(6,583)	(30)
Proceeds from Issuance of Common Stock	7,465	38,923	30,699	383,170	240,596
Repurchase of common stock	(18,900)	(3,798)	(5,742)	(1,627)	0
Payments of Ordinary Dividends, Preferred Stock and Preference Stock			0	0	(398)
Payment of offering costs- preferred shares	(3,660)	(6,695)
Distributions to noncontrolling interests	(45)	(8)	(11)	(11)	(11)
Distributions to common stockholders	(15,420)	(14,318)	(19,232)	(11,541)	(2,632)
Net cash used in financing activities	(31,816)	28,374	29,984	563,313	500,522
Net (decrease) increase in cash, cash equivalents and restricted cash	2,378	(4,987)	(17,511)	45,951	11,439
Cash, cash equivalents and restricted cash at the beginning of the period	46,050	63,561	63,561	17,610	6,171
Cash, cash equivalents and restricted cash at the end of the period	48,428	58,574	46,050	63,561	17,610
Supplemental Disclosures of Significant Non-cash Transactions:
Cash paid for interest			13,116	9,228	2,616
Noncash Investing and Financing Items [Abstract]
Reclassification from escrow account receivables to building and improvements	2,905	0
Change in fair value of swap agreement	(641)	(17)	108	841	0
Common stock issued pursuant to the distribution reinvestment plan	0
Assets and liabilities assumed in conjunction with the Signature Office REIT merger:
Increase (Decrease) in Distributions Payable to Common Stockholders	77	118	195	938	541
Increase (Decrease) in Stock Service Fee Payable	174	564	660	17,449	25
Stock Issued	16,422	16,546	22,208	15,158	4,515
Griffin Capital Essential Asset REIT, Inc. [Member]
Operating Activities:
Net income	18,769	32,911	146,133	26,555	15,621
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of building and building improvements	44,390	42,244	55,982	56,707	43,320
Amortization of leasing costs and intangibles, including ground leasehold interests	44,868	46,539	60,601	74,142	69,428
Amortization of above and below market leases	(135)	1,310	1,689	3,287	(3,785)
Amortization of deferred financing costs and debt premium	2,293	1,680	2,858	2,696	3,764
Amortization of deferred financing costs			(414)	(1,096)	(285)
Amortization of deferred revenue			0	(1,228)	(282)
Deferred rent			(11,372)	(14,751)	(13,792)
Write off of tenant improvement reserve			0	(1,000)	0
Termination fee revenue - release of tenant obligation			0	0	(2,078)
Termination fee revenue - receivable from tenant, net	(6,304)	(12,845)	(12,845)	0	(2,904)
Principal Investment Gains Losses on Unconsolidated Entity			0	(666)	0
Gain from sale of depreciable operating property	(1,158)	(4,293)	(116,382)	0	(13,813)
Unrealized loss on interest rate swap	2	48	68	70	23
Loss from investment in unconsolidated entities	1,617	1,511	2,065	1,640	1,475
Impairment provision	0	5,675	8,460	0	0
Stock-based compensation	37	153	173	18	12
Amortization of swap interest	94	0
Change in operating assets and liabilities:
Deferred leasing costs and other assets	1,118	1,767	3,332	1,615	(19,331)
Restricted reserves	(30)	427	(175)	(718)	(1,297)
Accrued expenses and other liabilities	7,441	281	1,098	(3,695)	19,978
Due to affiliates, net	478	1,517	826	(6,119)	3,918
Net cash provided by operating activities	103,270	110,417	142,097	137,457	99,972
Investing Activities:
Acquisition of properties, net	(182,250)	0	(134,130)	(7,897)	(401,418)
Cash assumed from SOR merger			0	0	8,557
Proceeds from disposition of properties	1,383	10,245	394,502	0	90,323
Real estate acquisition deposits	(3,350)	0	(1,350)	0	0
Reserves for tenant improvements	3	0	0	(692)	(21,542)
Improvements to real estate	0	(421)	(760)	(7,141)	(7,173)
Payments for construction-in-progress	(17,934)	(8,435)	(11,293)	(8,446)	(5,448)
Investment in unconsolidated joint venture	(3,266)	0	0	(18,129)	0
Payments for (Proceeds from) Mortgage Receivable from Affiliate			0	25,741	(24,231)
Payments For Accounts Payable And Other Liabilities For Real Estate Development			0	0	(48,314)
Distributions of capital from investment in unconsolidated entities	5,627	5,730	7,599	7,931	7,722
Net cash (used in) provided by investing activities	(199,787)	7,119	254,568	9,496	(401,524)
Financing Activities:
Proceeds from borrowings - Bank of America Loan	0	375,000	0	75,000	640,000
Proceeds from Issuance of First Mortgage Bond			0	0	490,100
Proceeds from borrowings - Revolver Loan	96,100	44,000	54,000	55,100	481,653
Principal payoff of secured indebtedness - Mortgage Debt	(18,954)	(41,462)
Principal amortization payments on secured indebtedness	(4,896)	(4,781)	(6,491)	(4,416)	(2,283)
Partial principal payoff of TW Telecom loan	0	(324)
Proceeds from (Repayments of) Secured Debt			375,000	0	0
Principal payoff of secured indebtedness - Revolver Loan	(106,253)	(294,054)	(41,493)	(35,954)	(31,407)
Deferred financing costs	(24)	(3,261)	(3,329)	(740)	(4,872)
Repurchase of common stock	(76,912)	(61,432)	(98,906)	(41,443)	(13,819)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock			0	0	(10,859)
Issuance of perpetual convertible preferred shares	125,000	0
Payment of offering costs- preferred shares	(4,727)	0	0	0	(62)
Distributions to noncontrolling interests	(3,556)	(3,556)	(4,737)	(4,425)	(3,477)
Distributions to common stockholders	(53,817)	(53,418)	(71,124)	(69,463)	(52,407)
Net cash used in financing activities	(48,039)	(43,288)	(238,660)	(183,814)	274,942
Net (decrease) increase in cash, cash equivalents and restricted cash	(144,556)	74,248	158,005	(36,861)	(26,610)
Cash, cash equivalents and restricted cash at the beginning of the period	214,867	56,862	56,862	93,723	120,333
Cash, cash equivalents and restricted cash at the end of the period	70,311	131,110	214,867	56,862	93,723
Supplemental Disclosures of Significant Non-cash Transactions:
Cash paid for interest			48,253	45,692	27,518
Noncash Investing and Financing Items [Abstract]
Limited partnership units of the operating partnership issued in conjunction with the acquisition of real estate assets by affiliates			0	11,941	7,282
Increase in fair value swap agreement	7,182	3,423
Common stock redemptions funded subsequent to period-end	39,107	37,559	20,382	11,565	6,336
Common stock issued pursuant to the distribution reinvestment plan	$ 33,667	$ 37,438	49,541	52,174	52,557
Assets and liabilities assumed in conjunction with the Signature Office REIT merger:
Mortgage debt assumed in conjunction with the acquisition of real estate assets			0	22,441	73,701
Payments to Acquire Additional Interest in Subsidiaries			0	0	(254,525)
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)			(6,795)	2,204	(6,560)
Payments For Construction In Process, Real Estate Development			0	0	(38,208)
Construction in Progress Expenditures Incurred but Not yet Paid			0	0	(10,106)
Increase (Decrease) in Distributions Payable to Common Stockholders			32	162	2,637
Increase (Decrease) In Distributions Payable To Preferred Stockholders			0	0	(1,615)
Distributions to Redeemable Noncontrolling Interests Attributable to Common Stockholders			356	358	359
Revolver Loan, July 2015 [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Financing Activities:
Principal payoff of secured indebtedness - Revolver Loan			(441,256)	(139,344)	0
Unsecured Revolver, May 2014 [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Financing Activities:
Principal payoff of secured indebtedness - Revolver Loan			0	0	(490,100)
Unsecured Debt | Griffin Capital Essential Asset REIT, Inc. [Member]
Financing Activities:
Repayments of Unsecured Debt			0	0	(300,000)
Revolving Credit Facility | Griffin Capital Essential Asset REIT, Inc. [Member]
Financing Activities:
Principal payoff of secured indebtedness - Revolver Loan			0	0	(173,000)
TW Telecom Loan [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Financing Activities:
Principal payoff of secured indebtedness - Mortgage Debt			(324)	0	0
Signature Office REIT Inc. [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Assets and liabilities assumed in conjunction with the Signature Office REIT merger:
Land			0	0	71,529
Building and improvements			0	0	436,350
Tenant origination and absorption cost			0	0	89,357
Above market leases			0	0	16,860
Above market leases			0	0	2,148
Mortgage debt assumed in conjunction with the acquisition of real estate assets			0	0	173,000
Below market leases			0	0	6,996
Accounts payable and other liabilities			0	0	11,138
Equity consideration for the SOR merger			$ 0	$ 0	$ 433,667

Organization

Organization	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Organization, Consolidation, And Presentation Of Financial Statements [Line Items]
Organization	Organization Griffin Capital Essential Asset REIT II, Inc., a Maryland corporation (the “Company”), was formed on November 20, 2013 under the Maryland General Corporation Law and qualified as a real estate investment trust (“REIT”) commencing with the year ended December 31, 2015. The Company was organized primarily with the purpose of acquiring single tenant net lease properties that are considered essential to the occupying tenant, and has used a substantial amount of the net proceeds from its initial public offering ("IPO") to invest in such properties. The Company’s year end is December 31. Griffin Capital Company, LLC, a Delaware limited liability company (the “Sponsor”), is the sponsor of the Company. The Sponsor, which was formerly known as Griffin Capital Corporation, began operations in 1995 to engage principally in acquiring and developing office and industrial properties. Kevin A. Shields, the Company's Chief Executive Officer and Chairman of the Company's board of directors, controls the Sponsor. Griffin Capital Essential Asset Advisor II, LLC, a Delaware limited liability company (the “Advisor”), was formed on November 19, 2013. Griffin Capital Real Estate Company, LLC, a Delaware limited liability company ("GRECO"), is the sole member of the Advisor and Griffin Capital, LLC, a Delaware limited liability company ("GC"), is the sole member of GRECO. The Sponsor is the sole member of GC. The Advisor is responsible for managing the Company’s affairs on a day-to-day basis and identifying and making acquisitions and investments on behalf of the Company under the terms of the Advisory Agreement (as defined below). The Company's officers are also officers of the Advisor and officers of the Sponsor. Griffin Capital Securities, LLC (the “Dealer Manager”) is a Delaware limited liability company and is a wholly-owned subsidiary of GC. The Dealer Manager is responsible for marketing the Company’s shares offered pursuant to the Company's public offerings. The Company’s property manager is Griffin Capital Essential Asset Property Management II, LLC, a Delaware limited liability company (the “Property Manager”), which was formed on November 19, 2013 to manage the Company’s properties, or provide oversight of other property managers engaged by the Company or an affiliate of the Company. The Property Manager derives substantially all of its income from the property management services it performs for the Company. Griffin Capital Essential Asset Operating Partnership II, L.P., a Delaware limited partnership (the “Operating Partnership”), was formed on November 21, 2013. On February 11, 2014, the Advisor purchased a 99% limited partnership interest and special limited partnership interest in the Operating Partnership for $0.2 million and on February 11, 2014, the Company contributed the initial one thousand dollars capital contribution it received to the Operating Partnership in exchange for a 1% general partner interest. The Operating Partnership owns, and will own, directly or indirectly, all of the properties acquired by the Company. The Operating Partnership will conduct certain activities through the Company’s taxable REIT subsidiary, Griffin Capital Essential Asset TRS II, Inc., a Delaware corporation (the “TRS”), formed on November 22, 2013, which is a wholly-owned subsidiary of the Operating Partnership. The TRS had no activity as of September 30, 2018 . In 2014, the Company registered $2.2 billion in common stock in its IPO, consisting of $2.0 billion in common stock to be offered to the public in the primary portion of the IPO and $200.0 million in common stock for sale pursuant to the Company's distribution reinvestment plan (“DRP”). (See Note 8, Equity, for additional details.) In September 2016, the Company's board of directors approved the close of the primary portion of the IPO effective January 20, 2017; however, the Company continued to offer shares pursuant to the DRP under the Company's IPO registration statement through May 2017. On April 6, 2017, the Company filed a Registration Statement on Form S-3 with the Securities and Exchange Commission ("SEC") for the registration of 3.0 million shares for sale pursuant to the DRP. The DRP may be terminated at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company's filings with the SEC. On September 20, 2017, the Company commenced a follow-on offering of up to $2.2 billion of shares (the "Follow-On Offering"), consisting of up to $2.0 billion of shares in the Company's primary offering and $0.2 billion of shares pursuant to the DRP. Pursuant to the Follow-On Offering, the Company offered to the public four new classes of shares of common stock: Class T shares, Class S shares, Class D shares and Class I shares (the “New Shares”) with net asset value (“NAV”) based pricing. The share classes have different selling commissions, dealer manager fees and ongoing distribution fees. In connection with the Follow-On Offering, the Company reclassified all Class T and Class I shares sold in the IPO as "Class AA" and "Class AAA" shares, respectively. On September 20, 2017, the Company entered into an amended and restated advisory agreement (the "Advisory Agreement") with the Advisor and the Operating Partnership, which replaced the original advisory agreement and modified various provisions including the fees and expense reimbursements payable to the Advisor. See Note 10, Related Party Transactions , for additional details. On September 20, 2017, the Company, as general partner of the Operating Partnership, entered into a Third Amended and Restated Limited Partnership Agreement of the Operating Partnership (the "Third Amended and Restated Operating Partnership Agreement") on behalf of itself and the limited partners. The Third Amended and Restated Operating Partnership Agreement is substantially similar to the Company's prior limited partnership agreement, except that it has been updated to reflect changes to the distributions and fees to which the Advisor is entitled, include additional classes of Operating Partnership units, and make other conforming changes. See Note 10, Related Party Transactions , for additional details. In connection with the Follow-On Offering, the Company's board of directors adopted an amended and restated DRP effective as of September 30, 2017 to include the New Shares under the DRP. In connection with the Follow-On Offering, the Company’s board of directors adopted a share redemption program for the New Shares (the “New Share Redemption Program”). Under this program, stockholders of the New Shares are allowed to redeem their shares after a one -year holding period at a redemption price equal to the NAV per share for the applicable class generally on the 13th of the month prior to quarter end. On March 30, 2018, the board of directors of the Company amended the IPO Share Redemption Program (as defined in Note 8, Equity ). The key change to the IPO Share Redemption Program is that after one year from the purchase date, a stockholder will be able to redeem at 100% of the NAV of the applicable share class. The amendment took effect on May 2, 2018. See Note 8, Equity , for additional details. On June 4, 2018, the board of directors of the Company approved the termination of the IPO Share Redemption Program, effective as of July 5, 2018. In addition, effective as of such date, the board of directors amended and restated the New Share Redemption Program in order to allow stockholders of the IPO shares to utilize the New Share Redemption Program. Accordingly, beginning in July 2018, stockholders of IPO shares will be able to continue to redeem at 100% of the NAV, calculated as of September13, 2018 of the applicable share class, subject to the other limitations and conditions of the amended and restated New Share Redemption Program. On August 16, 2018, in connection with a potential strategic alternative the Company’s board of directors is contemplating, the board approved the temporary suspension of the primary portion of the Company's Follow-On Offering, effective August 17, 2018, to allow the special committee of the board to evaluate a potential strategic alternative. The board of directors intends to recommence the Follow-On Offering in the retail marketplace, if appropriate and at the appropriate time.	Organization Griffin Capital Essential Asset REIT II, Inc., a Maryland corporation (the “Company”), was formed on November 20, 2013 under the Maryland General Corporation Law and qualified as a real estate investment trust (“REIT”) commencing with the year ended December 31, 2015. The Company was organized primarily with the purpose of acquiring single tenant net lease properties that are considered essential to the occupying tenant, and has used a substantial amount of the net proceeds from its initial public offering (“IPO”) to invest in such properties. The Company’s year end is December 31. Griffin Capital Company, LLC, a Delaware limited liability company (the “Sponsor”), is the sponsor of the Company. The Sponsor, which was formerly known as Griffin Capital Corporation, began operations in 1995 to engage principally in acquiring and developing office and industrial properties. Kevin A. Shields, the Company’s Chief Executive Officer and Chairman of the Company’s board of directors, controls the Sponsor. Griffin Capital Essential Asset Advisor II, LLC, a Delaware limited liability company (the “Advisor”), was formed on November 19, 2013. Griffin Capital Real Estate Company, LLC, a Delaware limited liability company (“GRECO”), is the sole member of the Advisor and Griffin Capital, LLC, a Delaware limited liability company (“GC”), is the sole member of GRECO. The Sponsor is the sole member of GC. The Advisor is responsible for managing the Company’s affairs on a day-to-day basis and identifying and making acquisitions and investments on behalf of the Company under the terms of the Advisory Agreement (as defined below). The Company’s officers are also officers of the Advisor and officers of the Sponsor. Griffin Capital Securities, LLC (the “Dealer Manager”) is a Delaware limited liability company and is a wholly-owned subsidiary of GC. The Dealer Manager is responsible for marketing the Company’s shares offered pursuant to the Company’s public offerings. The Company’s property manager is Griffin Capital Essential Asset Property Management II, LLC, a Delaware limited liability company (the “Property Manager”), which was formed on November 19, 2013 to manage the Company’s properties, or provide oversight of other property managers engaged by the Company or an affiliate of the Company. The Property Manager derives substantially all of its income from the property management services it performs for the Company. Griffin Capital Essential Asset Operating Partnership II, L.P., a Delaware limited partnership (the “Operating Partnership”), was formed on November 21, 2013. On February 11, 2014, the Advisor purchased a 99% limited partnership interest and special limited partnership interest in the Operating Partnership for $0.2 million and on February 11, 2014, the Company contributed the initial one thousand dollars capital contribution it received to the Operating Partnership in exchange for a 1% general partner interest. The Operating Partnership owns, and will own, directly or indirectly, all of the properties acquired by the Company. The Operating Partnership will conduct certain activities through the Company’s taxable REIT subsidiary, Griffin Capital Essential Asset TRS II, Inc., a Delaware corporation (the “TRS”), formed on November 22, 2013, which is a wholly-owned subsidiary of the Operating Partnership. The TRS had no activity as of December 31, 2017 . In 2014, the Company registered $2.2 billion in common stock in its IPO, consisting of $2.0 billion in common stock to be offered to the public in the primary portion of the IPO and $200.0 million in common stock for sale pursuant to the Company’s distribution reinvestment plan (“DRP”). (See Note 8, Equity , for additional details.) In September 2016, the Company’s board of directors approved the close of the primary portion of the IPO effective January 20, 2017; however, the Company continued to offer shares pursuant to the DRP under the Company’s IPO registration statement through May 2017. On April 6, 2017, the Company filed a Registration Statement on Form S-3 with the Securities and Exchange Commission (“SEC”) for the registration of 3.0 million shares for sale pursuant to the DRP. The DRP may be terminated at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company’s filings with the SEC. On September 20, 2017, the Company commenced a follow-on offering of up to $2.2 billion of shares, consisting of up to $2.0 billion of shares in the Company’s primary offering and $0.2 billion of shares pursuant to the DRP. The Company reclassified all Class T and Class I shares sold in the IPO as “Class AA” and “Class AAA” shares, respectively. The Company is offering to the public four new classes of shares of common stock: Class T shares, Class S shares, Class D shares and Class I shares (the “New Shares”) with net asset value (“NAV”) based pricing. The share classes have different selling commissions, dealer manager fees and ongoing distribution fees. On September 20, 2017, an affiliated entity purchased 263,992 New Shares for $2.5 million . The Company’s charter authorizes up to 1,000,000,000 shares of stock, of which 800,000,000 shares are designated as common stock at $0.001 par value per share and 200,000,000 shares are designated as preferred stock at $0.001 par value per share. The Company’s 800,000,000 shares of common stock are authorized as follows: 150,000,000 shares are classified as Class T shares, 150,000,000 shares are classified as Class S shares, 150,000,000 shares are classified as Class D shares, 150,000,000 shares are classified as Class I shares, 70,000,000 shares are classified as Class A shares, 120,000,000 shares are classified as Class AA shares and 10,000,000 shares are classified as Class AAA shares. The Dealer Manager is responsible for marketing the Company’s shares being offered pursuant to the follow-on offering. On September 18, 2017, the Company and the Dealer Manager entered into a dealer manager agreement for the follow-on offering. The dealer manager agreement may be terminated by either party upon prior written notice. See Note 10, Related Party Transactions , for additional details. The Company, the Operating Partnership and the Advisor were parties to an advisory agreement dated July 31, 2014, as amended by Amendment No. 1 to Advisory Agreement dated March 18, 2015, Amendment No. 2 to Advisory Agreement dated November 2, 2015, Amendment No. 3 to Advisory Agreement dated December 16, 2015, Amendment No. 4 to Advisory Agreement dated February 9, 2016 and Amendment No. 5 to Advisory Agreement dated June 14, 2017 (collectively, the “Original Advisory Agreement”), pursuant to which the Advisor agreed to provide certain services to the Company and the Operating Partnership, and the Company agreed to provide certain compensation to the Advisor in exchange for such services. On September 20, 2017, the Company entered into an amended and restated advisory agreement (the “Advisory Agreement”) with the Advisor and the Operating Partnership, which replaced the Original Advisory Agreement and modified various provisions including the fees and expense reimbursements payable to the Advisor. See Note 10, Related Party Transactions , for additional details. On September 20, 2017, the Company, as general partner of the Operating Partnership, entered into a Third Amended and Restated Limited Partnership Agreement of the Operating Partnership (the “Third Amended and Restated Operating Partnership Agreement”) on behalf of itself and the limited partners. The Third Amended and Restated Operating Partnership Agreement is substantially similar to the Company’s prior limited partnership agreement, except that it has been updated to reflect changes to the distributions and fees to which the Advisor is entitled, include additional classes of Operating Partnership units, and make other conforming changes. See Note 10, Related Party Transactions , for additional details. In connection with the follow-on offering, the Company’s board of directors adopted an amended and restated DRP effective as of September 30, 2017 to include the New Shares under the DRP. In connection with the follow-on offering, the Company’s board of directors adopted a share redemption program for the New Shares (the “New Share Redemption Program”). Under this program, stockholders of the New Shares are allowed to redeem their shares after a one -year holding period at a redemption price equal to the NAV per share for the applicable class generally on the 13th of the month immediately prior to the end of the applicable quarter. The IPO Share Redemption Program (as defined in Note 8, Equity ) remains available for stockholders who purchased shares in the Company’s IPO. See Note 8, Equity , for additional details.
Griffin Capital Essential Asset REIT, Inc. [Member]
Organization, Consolidation, And Presentation Of Financial Statements [Line Items]
Organization	Organization Griffin Capital Essential Asset REIT, Inc., a Maryland corporation (the "Company"), was formed on August 28, 2008 under the Maryland General Corporation Law and qualified as a real estate investment trust ("REIT") commencing with the year ended December 31, 2010. The Company was organized primarily with the purpose of acquiring single tenant properties that are essential to the tenant’s business and used a substantial amount of the net proceeds from the Public Offerings (as defined below) to invest in these properties. The Company’s year end is December 31. Griffin Capital Company, LLC, a Delaware limited liability company (the "Sponsor"), has sponsored the Company’s Public Offerings. The Sponsor, which was formerly known as Griffin Capital Corporation, began operations in 1995 to engage principally in acquiring and developing office and industrial properties. Kevin A. Shields, the Company's Chief Executive Officer and Chairman of the Company's board of directors, controls the Sponsor. Griffin Capital Essential Asset Advisor, LLC, a Delaware limited liability company (the "Advisor"), was formed on August 27, 2008. Griffin Capital Real Estate Company, LLC ("GRECO") is the sole member of the Advisor, and Griffin Capital, LLC is the sole member of GRECO. The Company has entered into an advisory agreement with the Advisor (as amended and restated, the "Advisory Agreement"), which states that the Advisor is responsible for managing the Company’s affairs on a day-to-day basis and identifying and making acquisitions and investments on behalf of the Company. The officers of the Advisor are also officers of the Sponsor. The Advisory Agreement has a one -year term, and it may be renewed for an unlimited number of successive one -year periods by the Company's board of directors. The Company’s property manager is Griffin Capital Essential Asset Property Management, LLC, a Delaware limited liability company (the “Property Manager”), which was formed on August 28, 2008 to manage the Company’s properties. The Property Manager derives substantially all of its income from the property management services it performs for the Company. From 2009 to 2014, the Company offered shares of common stock pursuant to a private placement offering to accredited investors (the "Private Offering") and two public offerings, consisting of an initial public offering and a follow-on offering (together, the "Public Offerings"), which included shares for sale pursuant to the distribution reinvestment plan ("DRP"). The Company issued 126,592,885 total shares of its common stock for gross proceeds of approximately $1.3 billion pursuant to the Private Offering and Public Offerings. The Company also issued approximately 41,800,000 shares of its common stock upon the consummation of the merger of Signature Office REIT, Inc. in June 2015. On May 7, 2014, the Company filed a Registration Statement on Form S-3 with the Securities and Exchange Commission ("SEC") for the registration of $75.0 million in shares for sale pursuant to the DRP (the “2014 DRP Offering”). On September 22, 2015, the Company filed a Registration Statement on Form S-3 with the SEC for the registration of $100.0 million in shares for sale pursuant to the DRP (the “2015 DRP Offering”). On June 9, 2017, the Company filed a Registration Statement on Form S-3 with the SEC for the registration of 10 million shares for sale pursuant to the DRP (the "2017 DRP Offering," and together with the 2014 DRP Offering and 2015 DRP Offering, the "DRP Offerings"). The 2017 DRP Offering may be terminated at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company's filings with the SEC. As of September 30, 2018 , the Company had issued 190,116,953 shares of common stock. The Company has received aggregate gross offering proceeds of approximately $1.5 billion from the sale of shares in the Private Offering, the Public Offerings, and the DRP Offerings. There were 166,253,534 shares outstanding at September 30, 2018 , including shares issued pursuant to the DRP, less shares redeemed pursuant to the share redemption program ("SRP"). As of September 30, 2018 and December 31, 2017 , the Company had issued approximately $245.6 million and $211.9 million , respectively, in shares pursuant to the DRP, which are classified on the consolidated balance sheets as common stock subject to redemption, net of redemptions paid of approximately $234.6 million , and redemptions payable totaling approximately $6.7 million and $20.4 million , respectively. Since inception and through September 30, 2018 , the Company had redeemed 23,863,419 shares of common stock for approximately $234.6 million pursuant to the SRP. Griffin Capital Essential Asset Operating Partnership, L.P., a Delaware limited partnership (the "Operating Partnership"), was formed on August 29, 2008. The Operating Partnership owns, directly or indirectly, all of the properties that the Company has acquired. The Advisor purchased an initial 99% limited partnership interest in the Operating Partnership for $0.2 million, and the Company contributed the initial one thousand dollars capital contribution, received from the Advisor, to the Operating Partnership in exchange for a 1% general partner interest. As of September 30, 2018 , the Company owned approximately 96% of the limited partnership units of the Operating Partnership, and, as a result of the contribution of five properties to the Company, the Sponsor and certain of its affiliates, including certain officers of the Company, owned approximately 2% of the limited partnership units of the Operating Partnership. Approximately 2.1 million units are owned by the Company’s Chief Executive Officer and Chairman, Kevin A. Shields. The remaining approximately 2% of the limited partnership units are owned by unaffiliated third parties. No limited partnership units of the Operating Partnership have been redeemed during the nine months ended September 30, 2018 and the year ended December 31, 2017 . The Operating Partnership may conduct certain activities through the Company’s taxable REIT subsidiary, Griffin Capital Essential Asset TRS, Inc., a Delaware corporation (the "TRS"), formed on September 2, 2008, which is a wholly-owned subsidiary of the Operating Partnership. The TRS had no activity as of September 30, 2018 .	Organization Griffin Capital Essential Asset REIT, Inc., a Maryland corporation (the “Company”), was formed on August 28, 2008 under the Maryland General Corporation Law and qualified as a real estate investment trust (“REIT”) commencing with the year ended December 31, 2010. The Company was organized primarily with the purpose of acquiring single tenant properties that are essential to the tenant’s business and used a substantial amount of the net proceeds from the Public Offerings (as defined below) to invest in these properties. The Company’s year end is December 31. Griffin Capital Company, LLC, a Delaware limited liability company (the “Sponsor”), has sponsored the Company’s Public Offerings. The Sponsor, which was formerly known as Griffin Capital Corporation, began operations in 1995 to engage principally in acquiring and developing office and industrial properties. Kevin A. Shields, the Company’s Chief Executive Officer and Chairman of the Company’s board of directors, controls the Sponsor. Griffin Capital Essential Asset Advisor, LLC, a Delaware limited liability company (the “Advisor”), was formed on August 27, 2008. Griffin Capital Real Estate Company, LLC (“GRECO”) is the sole member of the Advisor, and Griffin Capital, LLC is the sole member of GRECO. The Company has entered into an advisory agreement with the Advisor (as amended and restated, the “Advisory Agreement”), which states that the Advisor is responsible for managing the Company’s affairs on a day-to-day basis and identifying and making acquisitions and investments on behalf of the Company. The officers of the Advisor are also officers of the Sponsor. The Advisory Agreement has a one -year term, and it may be renewed for an unlimited number of successive one -year periods by the Company’s board of directors. The Company’s property manager is Griffin Capital Essential Asset Property Management, LLC, a Delaware limited liability company (the “Property Manager”), which was formed on August 28, 2008 to manage the Company’s properties. The Property Manager derives substantially all of its income from the property management services it performs for the Company. From 2009 to 2014, the Company offered shares of common stock pursuant to a private placement offering to accredited investors (the “Private Offering”) and two public offerings, consisting of an initial public offering and a follow-on offering (together, the “Public Offerings”), which included shares of common stock for sale pursuant to the distribution reinvestment plan (“DRP”). The Company issued 126,592,885 total shares of its common stock for gross proceeds of approximately $ 1.3 billion pursuant to the Private Offering and the Public Offerings. The Company also issued approximately 41,800,000 shares of its common stock upon the consummation of the merger of Signature Office REIT, Inc. in June 2015. On May 7, 2014, the Company filed a Registration Statement on Form S-3 with the Securities and Exchange Commission (“SEC”) for the registration of $75.0 million in shares for sale pursuant to the DRP (the “2014 DRP Offering”). On September 22, 2015, the Company filed a Registration Statement on Form S-3 with the SEC for the registration of $100.0 million in shares of common stock for sale pursuant to the DRP (the “2015 DRP Offering”). On June 9, 2017, the Company filed a Registration Statement on Form S-3 with the SEC for the registration of 10 million shares of common stock for sale pursuant to the DRP (the “2017 DRP Offering,” and together with the 2014 DRP Offering and 2015 DRP Offering, the “DRP Offerings”). The 2017 DRP Offering may be terminated at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company’s filings with the SEC. As of December 31, 2017 , the Company had issued 186,756,009 shares of common stock. The Company has received aggregate gross offering proceeds of approximately $1.5 billion from the sale of shares in the Private Offering, the Public Offerings, and the DRP Offerings. There were 170,906,111 shares of common stock outstanding as of December 31, 2017 , including shares of common stock issued pursuant to the DRP, less shares redeemed pursuant to the share redemption program (“SRP”). As of December 31, 2017 and 2016 , the Company had issued approximately $211.9 million and $162.4 million , respectively, in shares of common stock pursuant to the DRP, which are classified on the consolidated balance sheets as common stock subject to redemption, net of redemptions paid of approximately $157.7 million and $58.8 million , respectively, and redemptions payable totaling approximately $20.4 million and $11.6 million , respectively, which are included in accrued expenses and other liabilities on the consolidated balance sheets. Since inception and through December 31, 2017 , the Company had redeemed 15,849,898 shares of common stock for approximately $157.7 million pursuant to the SRP. Griffin Capital Essential Asset Operating Partnership, L.P., a Delaware limited partnership (the “Operating Partnership”), was formed on August 29, 2008. The Operating Partnership owns, directly or indirectly, all of the properties that the Company has acquired. The Advisor purchased an initial 99% limited partnership interest in the Operating Partnership for $0.2 million , and the Company contributed the initial one thousand dollars capital contribution, received from the Advisor, to the Operating Partnership in exchange for a 1% general partner interest. As of December 31, 2017 , the Company owned approximately 96% of the limited partnership units of the Operating Partnership, and, as a result of the contribution of five properties to the Company, the Sponsor and certain of its affiliates, including certain officers of the Company, owned approximately 2% of the limited partnership units of the Operating Partnership. Approximately 2.1 million units are owned by the Company’s Chief Executive Officer and Chairman, Kevin A. Shields. The remaining approximately 2% of the limited partnership units are owned by unaffiliated third parties. No limited partnership units of the Operating Partnership have been redeemed during the years ended December 31, 2017 and 2016 . The Operating Partnership may conduct certain activities through the Company’s taxable REIT subsidiary, Griffin Capital Essential Asset TRS, Inc., a Delaware corporation (the “TRS”), formed on September 2, 2008, which is a wholly-owned subsidiary of the Operating Partnership. The TRS had no activity as of December 31, 2017 .

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Accounting Policies [Line Items]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies There have been no significant changes to the Company’s accounting policies since the Company filed its audited financial statements in its Annual Report on Form 10-K for the year ended December 31, 2017 . For further information about the Company’s accounting policies, refer to the Company’s consolidated financial statements and notes thereto for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K filed with the SEC. The accompanying unaudited consolidated financial statements of the Company are prepared by management on the accrual basis of accounting and in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information as contained in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”), and in conjunction with rules and regulations of the SEC. Certain information and footnote disclosures required for annual financial statements have been condensed or excluded pursuant to SEC rules and regulations. Accordingly, the unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. The unaudited consolidated financial statements include accounts and related adjustments, which are, in the opinion of management, of a normal recurring nature and necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the interim period. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . The consolidated financial statements of the Company include all accounts of the Company, the Operating Partnership, and its subsidiaries. Intercompany transactions are not shown on the consolidated statements. However, each property owning entity is a wholly owned subsidiary which is a special purpose entity ("SPE"), which assets and credit are not available to satisfy the debts or obligations of any other entity, except to the extent required with respect to any co-borrower or guarantor under the same credit facility. Use of Estimates The preparation of the unaudited consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Change in Consolidated Financial Statements Presentation During the year ended December 31, 2017, the Company elected to early adopt Accounting Standards Update ("ASU") No. 2016-18, Restricted Cash ("ASU No. 2016-18"). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the consolidated statements of cash flows. Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common stock outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common stock outstanding, including common stock equivalents. As of September 30, 2018 and December 31, 2017 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders. Segment Information ASC Topic 280, Segment Reporting , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment. Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging ("ASU No. 2017-12") . 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards, a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. This ASU is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company elected to early adopt ASU No. 2017-12 for the reporting period ending March 31, 2018. The adoption of ASU No. 2017-12 did not have a material effect on the Company's financial position or statement of operations. In February 2016, the FASB issued ASU No. 2016-02, Leases ("ASU No. 2016-02"). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued an amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which states that: (a) an entity need not reassess whether any expired or existing contracts are leases or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in May 2017 board meeting minutes that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In March 2018, the FASB approved a proposal to the drafting of an amendment to the ASU to allow lessors to elect, as a practical expedient, not to allocate the total consideration to lease and non-lease components based on their relative standalone selling prices. If adopted, this single-lease component practical expedient will allow lessors to elect a combined single-lease component presentation if (i) the timing and pattern of transfer of the lease component and the non-lease component(s) associated with it are the same, and (ii) the lease component would be classified as an operating lease if it were accounted for separately. Non-lease components that do not meet the criteria of this practical expedient and combined components in which the non-lease component is the predominant component will be accounted for under the new revenue recognition ASU. The Company does not expect that ASU No. 2016-02 will impact the Company's accounting for Fixed Lease Payments because the Company's accounting policy is currently consistent with the provisions of the standard. The Company is currently evaluating the impact of the standard as it relates to Non-Lease Payments. If the practical expedient mentioned above is adopted and the Company elects it, the Company expects payments for expense reimbursements that qualify as Non-Lease Payments will be presented under a single lease component presentation. However, without the proposed practical expedient, the Company expects these reimbursements would be separated into Fixed Lease Payments and Non-Lease Payments. Under ASU No. 2016-02, reimbursements relating to property taxes and insurances are Fixed Lease Payments as the payments relates to the right to use the leased assets, while reimbursements relating to maintenance activities and common area expense are Non-Lease Payments and would be accounted under ASU No. 2014-09 upon the adoption of the ASU No. 2016-02 as these payments for goods or services are transferred separately from the right to use the underlying assets. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 replaces substantially all industry-specific revenue recognition requirements and converges areas under this topic with International Financial Reporting Standards. ASU No. 2014-09 implements a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. ASU No. 2014-09 also requires enhanced disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows from contracts with customers. Other major provisions in ASU No. 2014-09 include capitalizing and amortizing certain contract costs, ensuring the time value of money is considered in the applicable transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. ASU No. 2014-09 was originally effective for reporting periods beginning after December 31, 2016 (for public entities). On April 1, 2015, the FASB voted to defer the effective date of ASU No. 2014-09 by one year to annual reporting periods beginning after December 15, 2017. On July 9, 2015, the FASB affirmed its proposal to defer the effective date to annual reporting periods beginning after December 15, 2017, although entities may elect to adopt the standard as of the original effective date. The Company adopted the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The impact was minimal upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of gains and losses on the sale of real estate assets as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Rental income from leasing arrangements is a substantial portion of the Company’s revenue, is specifically excluded from ASU No. 2014-09 and will be governed by the applicable lease codification ("ASU No. 2016-02"). In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU No. 2016-08"). The amendments clarify how an entity should identify the unit of accounting (i.e., the specified good or service) for the principal versus agent evaluation, and how it should apply the control principle to certain types of arrangements, such as service transactions, by explaining what a principal controls before the specified good or service is transferred to the customer. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements of ASU No. 2014-09 described above. The Company adopted the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The impact was minimal upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of reporting revenue gross versus net on its consolidated financial statements as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle.	Basis of Presentation and Summary of Significant Accounting Policies The accompanying cons olidated financial statements of the Company are prepared by management on the accrual basis of accounting and in accordance with generally accepted accounting principles in the United States (“GAAP”) as contained in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”), and in conjunction with rules and regulations of the SEC. The consolidated financial statements include accounts and related adjustments, which are, in the opinion of management, of a normal recurring nature and necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the years ended December 31, 2017 and 2016 . The consolidated financial statements of the Company include all accounts of the Company, the Operating Partnership, and its subsidiaries. Intercompany transactions are not shown on the consolidated statements. However, each property owning entity is a wholly owned subsidiary which is a special purpose entity (“SPE”), whose assets and credit are not available to satisfy the debts or obligations of any other entity, except to the extent required with respect to any co-borrower or guarantor under the same credit facility. Revenue Recognition Leases associated with the acquisition and contribution of certain real estate assets (see Note 3, Real Estate ) have net minimum rent payment increases during the term of the lease and are recorded to rental revenue on a straight-line basis, commencing as of the contribution or acquisition date. If a lease provides for contingent rental income, the Company will defer the recognition of contingent rental income, such as percentage rents, until the specific target that triggers the contingent rental income is achieved. Tenant reimbursement revenue, which is comprised of additional amounts collected from tenants for the recovery of certain operating expenses, including repair and maintenance, property taxes and insurance, and capital expenditures, to the extent allowed pursuant to the lease (collectively, “Recoverable Expenses”), is recognized as revenue when the additional rent is due. Recoverable Expenses to be reimbursed by a tenant are determined based on the Company’s estimate of the property’s operating expenses for the year, pro rated based on leased square footage of the property, and are collected in equal installments as additional rent from the tenant, pursuant to the terms of the lease. At least quarterly, the Company reconciles the amount of additional rent paid by the tenant during the quarter to the actual amount of the Recoverable Expenses incurred by the Company for the same period. The difference, if any, is either charged or credited to the tenant pursuant to the provisions of the lease. In certain instances, the lease may restrict the amount the Company can recover from the tenant such as a cap on certain or all property operating expenses. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Change in Consolidated Financial Statements Presentation Certain amounts in the Company’s prior period consolidated financial statements have been reclassified to conform to the current period presentation. During the year ended December 31, 2017, the Company elected to early adopt Accounting Standards Update (“ASU”) No. 2016-18 (as discussed below). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the consolidated statements of cash flows. Principles of Consolidation The Company’s financial statements, and the financial statements of the Company’s Operating Partnership, including its wholly-owned subsidiaries, are consolidated in the accompanying consolidated financial statements. The portion of these entities not wholly-owned by the Company is presented as noncontrolling interests. All significant intercompany accounts and transactions have been eliminated in consolidation. Cash and Cash Equivalents The Company considers all short-term, highly liquid investments that are readily convertible to cash with a maturity of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents may include cash and short-term investments. Short-term investments are stated at cost, which approximates fair value. There were no cash equivalents, nor were there restrictions on the use of the Company’s cash balance as of December 31, 2017 and 2016 . The Company maintains its cash accounts with major financial institutions. The cash balances consist of business checking accounts. These accounts are insured by the Federal Deposit Insurance Corporation up to $250,000 at each institution. The Company has not experienced any losses with respect to cash balances in excess of government provided insurance. Management believes there was no significant concentration of credit risk with respect to these cash balances as of December 31, 2017 . Restricted Cash In conjunction with acquisitions of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash. As of December 31, 2017 , the Company had approximately $12.9 million in restricted cash, which includes tenant improvement funds. Real Estate Purchase Price Allocation In January 2017, the FASB issued ASU No. 2017-01, Business Combinations, (see “Recently Issued Accounting Pronouncements” below) that clarifies the framework for determining whether an integrated set of assets and activities meets the definition of a business. The revised framework establishes a screen for determining whether an integrated set of assets and activities is a business and 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. This update is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2017, with early adoption permitted for transactions that have not been reported in previously issued (or available to be issued) financial statements. The Company adopted this accounting standard early effective October 1, 2016. As a result of the Company’s adoption of ASU No. 2017-01, Business Combinations, the Company anticipates that many of its future acquisitions will be treated as asset acquisitions, which will result in a lower amount of acquisition-related costs being expensed on the Company’s consolidated statement of operations, as the majority of those costs will be capitalized and included as part of the relative fair value allocation of the purchase price. The Company applies the provisions in ASC 805-10, Business Combinations , to account for the acquisition of real estate, or real estate related assets, in which a lease, or other contract, is in place representing an active revenue stream, as an asset acquisition (in rare cases, a business combination). In accordance with the provisions of ASC 805-10 (on an asset acquisition), the Company recognizes an asset acquisition, the assets acquired, the liabilities assumed and any noncontrolling interest in the acquired entity at their relative fair values. The accounting provisions have also established that transaction costs associated with an asset acquisition are capitalized. Acquired in-place leases are valued as above-market or below-market as of the date of acquisition. The valuation is measured based on the present value (using an interest rate, which reflects the risks associated with the leases acquired) of the difference between (a) the contractual amounts to be paid pursuant to the in-place leases and (b) management’s estimate of fair market lease rates for the corresponding in-place leases over a period equal to the remaining non-cancelable term of the lease for above-market leases, taking into consideration below-market extension options for below-market leases. In addition, renewal options are considered and will be included in the valuation of in-place leases if (1) it is likely that the tenant will exercise the option, and (2) the renewal rent is considered to be sufficiently below a fair market rental rate at the time of renewal. The above-market and below-market lease values are capitalized as intangible lease assets or liabilities and amortized as an adjustment to rental income over the remaining terms of the respective leases. The aggregate relative fair value of in-place leases includes direct costs associated with obtaining a new tenant, opportunity costs associated with lost rentals, which are avoided by acquiring an in-place lease, and tenant relationships. Direct costs associated with obtaining a new tenant include commissions, tenant improvements, and other direct costs and are estimated using methods similar to those used in independent appraisals and management’s consideration of current market costs to execute a similar lease. These direct costs are considered intangible lease assets and are included with real estate assets on the consolidated balance sheets. The intangible lease assets are amortized to expense over the remaining terms of the respective leases. The value of opportunity costs is calculated using the contractual amounts to be paid, including real estate taxes, insurance, and other operating expenses, pursuant to the in-place leases over a market lease-up period for a similar lease. Customer relationships are valued based on management’s evaluation of certain characteristics of each tenant’s lease and the Company’s overall relationship with that respective tenant. Characteristics management will consider in allocating these values include the nature and extent of the Company’s existing business relationships with tenants, growth prospects for developing new business with the tenant, the tenant’s credit quality and expectations of lease renewals (including those existing under the terms of the lease agreement), among other factors. These intangibles will be included in intangible lease assets on the consolidated balance sheets and are amortized to expense over the remaining term of the respective leases. The determination of the relative fair values of the assets and liabilities acquired requires the use of significant assumptions about current market rental rates, rental growth rates, discount rates and other variables. Depreciation and Amortization The purchase price of real estate acquired and the costs related to development, construction, and property improvements are capitalized. Repairs and maintenance costs include all costs that do not extend the useful life of the real estate asset and are expensed as incurred. The Company considers the period of future benefit of an asset to determine the appropriate useful life. The Company anticipates the estimated useful lives of its assets by class to be generally as follows: Buildings 40 years Building Improvements 5-20 years Land Improvements 15-25 years Tenant Improvements Shorter of estimated useful life or remaining contractual lease term Tenant Origination and Absorption Cost Remaining contractual lease term In-place Lease Valuation Remaining contractual lease term with consideration as to below-market extension options for below-market leases If a lease is terminated or amended prior to its scheduled expiration, the Company will accelerate the remaining useful life of the unamortized lease-related costs. Impairment of Real Estate and Related Intangible Assets The Company continually monitors events and changes in circumstances that could indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, including credit ratings of all tenants to stay abreast of any material changes in credit quality. The Company monitors tenant credit by (1) reviewing the credit ratings of tenants (or their parent companies or lease guarantors) that are rated by nationally recognized rating agencies; (2) reviewing financial statements and related metrics and information that are publicly available or that are required to be provided pursuant to the lease; (3) monitoring news reports and press releases regarding the tenants (or their parent companies or lease guarantors), and their underlying business and industry; and (4) monitoring the timeliness of rent collections. When indicators of potential impairment are present that indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, management assesses whether the carrying value of the assets will be recovered through the future undiscounted operating cash flows expected from the use of the assets and the eventual disposition. If, based on this analysis, the Company does not believe that it will be able to recover the carrying value of the asset, the Company will record an impairment charge to the extent the carrying value exceeds the net present value of the estimated future cash flows of the asset. Projections of expected future undiscounted cash flows require management to estimate future market rental income amounts subsequent to the expiration of current lease agreements, property operating expenses, discount rates, the number of months it takes to re-lease the property and the number of years the property is held for investment. For the year ended December 31, 2017 , the Company did not record any impairment charges related to its real estate assets or intangible assets . Derivative Instruments and Hedging Activities ASC Topic 815: Derivatives and Hedgin g (“ASC 815”), provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, ASC 815 requires qualitative disclosures regarding the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company recorded all derivatives on the consolidated balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, and whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. See Note 5, Interest Rate Contracts . Income Taxes The Company has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”) for the year ended December 31, 2015. To qualify as a REIT, the Company must meet certain organizational and operational requirements, including a requirement to currently distribute at least 90% of the REIT’s ordinary taxable income to stockholders. As a REIT, the Company generally will not be subject to federal income tax on taxable income that is distributed to stockholders. If the Company fails to qualify as a REIT in any taxable year, after the Company initially qualifies to be taxed as a REIT, the Company will then be subject to federal income taxes on the taxable income at regular corporate rates and will not be permitted to qualify for treatment as a REIT for federal income tax purposes for four years following the year during which qualification is lost unless the Internal Revenue Service grants the Company relief under certain statutory provisions. Such an event could materially adversely affect net income and net cash available for distribution to stockholders. However, the Company believes that it is organized and will operate in such a manner as to qualify for treatment as a REIT and intends to operate in the foreseeable future in such a manner that it will remain qualified as a REIT for federal income tax purposes. The Company could engage in certain business activities that could have an adverse effect on its REIT qualification. The Company has elected to isolate these business activities in the books and records of the TRS. In general, the TRS may perform additional services for the Company’s tenants and generally may engage in any real estate or non-real estate related business. The TRS will be subject to corporate federal and state income tax. As of December 31, 2017 , the TRS has not commenced operations. Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding, including common stock equivalents. As of December 31, 2017 and December 31, 2016 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders. The Company retroactively adjusted the number of shares of common stock outstanding in accordance with ASC 260-10, Earnings per Share. ASC 260-10 requires retroactively adjusting the computations of basic and diluted earnings per share for all periods presented to reflect the change in capital structure, if the number of shares of common stock outstanding increases as a result of a stock dividend or stock split or decreases as a result of a reverse stock split. If changes in common stock resulting from stock dividends, stock splits, or reverse stock splits occur after the close of the period but before the consolidated financial statements are issued or are available to be issued, the per-share computations for those and any prior-period consolidated financial statements presented shall be based on the new number of shares. Segment Information ASC Topic 280, Segment Reporting , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment. Unaudited Data Any references to the number of buildings, square footage, number of leases, occupancy, and any amounts derived from these values in the notes to the consolidated financial statements are unaudited and outside the scope of the Company’s independent registered public accounting firm’s audit of its consolidated financial statements in accordance with the standards of the Public Company Accounting Oversight Board. Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (“ASU No. 2017-12”), that simplifies hedge accounting. 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. ASU No. 2017-12 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. For cash flow hedges in existence at the date of adoption, an entity is required to apply a cumulative-effect adjustment for previously recognized ineffectiveness from retained earnings to accumulated other comprehensive income (“AOCI”), as of the beginning of the fiscal year when an entity adopts the amendments in this ASU. The Company utilizes interest rate hedge agreements to hedge a portion of exposure to variable interest rates primarily associated with borrowings based on London Interbank Offered Rate (“LIBOR”). As a result, all interest rate hedge agreements are designated as cash flow hedges. During the years ended December 31, 2017 and December 31, 2016 , the ineffectiveness related to the Company’s interest rate hedge agreement was immaterial. Therefore, the Company does not believe ASU No. 2017-12 would have an impact on operating results for the year ended December 31, 2017 . In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (“ASU No. 2017-01”), that clarified the definition of a business. ASU No. 2017-01 is effective for reporting periods beginning after December 15, 2017, with early adoption permitted. The Company adopted this update on October 1, 2016. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash (“ASU No. 2016-18”), that will require companies to include restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This ASU will require a disclosure of a reconciliation between the statement of financial position and the statement of cash flows when the statement of financial position includes more than one line item for cash, cash equivalents, restricted cash, and restricted cash equivalents. Entities with material restricted cash and restricted cash equivalents balances will be required to disclose the nature of the restrictions. This ASU is effective for reporting periods beginning after December 15, 2017, with early adoption permitted, and will be applied retrospectively to all periods presented. The Company elected to early adopt ASU No. 2016-18 for the reporting period ending December 31, 2017 and applied retrospectively to all periods presented. As a result of the adoption of ASU No. 2016-18, the Company no longer presents the changes within restricted cash in the consolidated statements of cash flows. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU No. 2016-15”). ASU No. 2016-15 addresses eight specific cash flow issues with the objective of reducing diversity in practice. The cash flow issues include debt prepayment or debt extinguishment costs and proceeds from the settlement of insurance claims. This ASU is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The Company elected to early adopt ASU No. 2016-15 for the reporting period ending December 31, 2017. There was no change to the Company’s consolidated financial statements or notes as a result of adoption. In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU No. 2016-02”). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued a proposed amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which allows for (a) an entity need not to reassess whether any expired or existing contracts are or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in board meeting minutes of May 2017 that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In January, 2018, the FASB issued a proposed amendment to ASU No. 2016-02 that would allow lessors to elect, as a practical expedient, not to allocate the total consideration to Fixed Lease Payments and Non-Lease Payments based on their relative standalone selling prices. If adopted, this practical expedient will allow lessors to elect a combined single component presentation if (i) the timing and pattern of the revenue recognition for the Fixed Lease Payments and Non-Lease Payments are the same, and (ii) the combined single component of the lease would continue to be classified as an operating lease. The Company does not expect that ASU 2016-02 will impact the Company’s accounting for Fixed Lease Payments, because the Company’s accounting policy is currently consistent with the provisions of the standard. The Company is currently evaluating the impact of the standard as it relates to Non-Lease Payments. If the proposed practical expedient mentioned above is adopted and the Company elects it, the Company expects payments for expense reimbursements that qualify as Non-Lease Payments will be presented under a single lease component presentation. However, without the proposed practical expedient, the Company expects these reimbursements would be separated into Fixed Lease Payments and Non-Lease Payments. Under ASU No. 2016-02, reimbursements relating to property taxes and insurances are Fixed Lease Payments as the payments relates to the right to use the leased assets, while reimbursements relating to maintenance activities and common area expense are Non-Lease Payments and would be accounted under ASU No. 2014-09 upon the adoption of the ASU No. 2016-02 as these payments for goods or services are transferred separately from the right to use the underlying assets. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 replaces substantially all industry-specific revenue recognition requirements and converges areas under this topic with International Financial Reporting Standards. ASU No. 2014-09 implements a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. ASU No. 2014-09 also requires enhanced disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows from contracts with customers. Other major provisions in ASU No. 2014-09 include capitalizing and amortizing certain contract costs, ensuring the time value of money is considered in the applicable transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. ASU No. 2014-09 was originally effective for reporting periods beginning after December 31, 2016 (for public entities). On April 1, 2015, the FASB voted to defer the effective date of ASU No. 2014-09 by one year to annual reporting periods beginning after December 15, 2017. On July 9, 2015, the FASB affirmed its proposal to defer the effective date to annual reporting periods beginning after December 15, 2017, although entities may elect to adopt the standard as of the original effective date. The Company intends to adopt the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The Company anticipates minimal impact upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of gains and losses on the sale of real estate assets as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Rental income from leasing arrangements is a substantial portion of the Company’s revenue, is specifically excluded from ASU No. 2014-09 and will be governed by the applicable lease codification (“ASU No. 2016-02”). In conjunction with the adoption of the leasing guidance, the Company is currently in the process of evaluating certain variable payment terms included in these lease arrangements which are governed by ASU No. 2014-09. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations ( Reporting Revenue Gross versus Net “ASU No. 2016-08”). The amendments clarify how an entity should identify the unit of accounting (i.e., the specified good or service) f
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Basis of Presentation and Summary of Significant Accounting Policies		Basis of Presentation and Summary of Significant Accounting Policies The accompanying cons olidated financial statements of the Company are prepared by management on the accrual basis of accounting and in accordance with generally accepted accounting principles in the United States (“GAAP”) as contained in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”), and in conjunction with rules and regulations of the SEC. The consolidated financial statements include accounts and related adjustments, which are, in the opinion of management, of a normal recurring nature and necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the years ended December 31, 2017 and 2016 . The consolidated financial statements of the Company include all accounts of the Company, the Operating Partnership, and its subsidiaries. Intercompany transactions are not shown on the consolidated statements. However, each property owning entity is a wholly owned subsidiary which is a special purpose entity, whose assets and credit are not available to satisfy the debts or obligations of any other entity, except to the extent required with respect to any co-borrower or guarantor under the same credit facility. Principles of Consolidation The Company’s financial statements, and the financial statements of the Company’s Operating Partnership, including its wholly-owned subsidiaries, are consolidated in the accompanying consolidated financial statements. The portion of these entities not wholly-owned by the Company is presented as noncontrolling interests. All significant intercompany accounts and transactions have been eliminated in consolidation. Consolidation Considerations Current accounting guidance provides a framework for identifying a variable interest entity (“VIE”) and determining when a company should include the assets, liabilities, noncontrolling interests, and results of activities of a VIE in its consolidated financial statements. In general, a VIE is an entity or other legal structure used to conduct activities or hold assets that either (1) has an insufficient amount of equity to carry out its principal activities without additional subordinated financial support, (2) has a group of equity owners that are unable to make significant decisions about its activities, or (3) has a group of equity owners that do not have the obligation to absorb losses or the right to receive returns generated by its operations. Generally, a VIE should be consolidated if a party with an ownership, contractual, or other financial interest in the VIE (a variable interest holder) has the power to direct the VIE’s most significant activities and the obligation to absorb losses or right to receive benefits of the VIE that could be significant to the VIE. A variable interest holder that consolidates the VIE is called the primary beneficiary. Upon consolidation, the primary beneficiary generally must initially record all of the VIE’s assets, liabilities, and noncontrolling interest at fair value and subsequently account for the VIE as if it were consolidated based on majority voting interest. See Note 4, Investments . Cash and Cash Equivalents The Company considers all short-term, highly liquid investments that are readily convertible to cash with a maturity of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents may include cash and short-term investments. Short-term investments are stated at cost, which approximates fair value. There were no cash equivalents, nor were there restrictions on the use of the Company’s cash balance as of December 31, 2017 and 2016 . The Company maintains its cash accounts with major financial institutions. The cash balances consist of business checking accounts. These accounts are insured by the Federal Deposit Insurance Corporation up to $250,000 at each institution. The Company has not experienced any losses with respect to cash balances in excess of government provided insurance. Management believes there was no significant concentration of credit risk with respect to these cash balances as of December 31, 2017 . Restricted Cash Restricted cash primarily consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential exchanges under Section 1031 of the Code (“Section 1031 Exchanges”). In addition, in conjunction with acquisitions of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash. As of December 31, 2017 , the Company had $154.9 million of restricted cash held at qualified intermediaries for the purpose of facilitating Section 1031 Exchanges. As of December 31, 2016 , the Company had no restricted cash held at qualified intermediaries for the purpose of facilitating Section 1031 Exchanges. Real Estate Purchase Price Allocation In January 2017, the FASB issued Accounting Standards Update (“ASU”) No. 2017-01, Business Combinations, (see “Recently Issued Accounting Pronouncements” below) that clarifies the framework for determining whether an integrated set of assets and activities meets the definition of a business. The revised framework establishes a screen for determining whether an integrated set of assets and activities is a business and 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. This update is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2017, with early adoption permitted for transactions that have not been reported in previously issued (or available to be issued) financial statements. The Company adopted this accounting standard early effective January 1, 2017. As a result of the Company’s adoption of ASU No. 2017-01, Business Combinations, the Company anticipates that many of its future acquisitions (if any) will be treated as asset acquisitions, which will result in a lower amount of acquisition-related costs being expensed on the Company’s consolidated statement of operations, as the majority of those costs will be capitalized and included as part of the relative fair value allocation of the purchase price. The Company applies the provisions in ASC 805-10, Business Combinations , to account for the acquisition of real estate, or real estate related assets, in which a lease, or other contract, is in place representing an active revenue stream, as an asset acquisition (in rare cases, a business combination). In accordance with the provisions of ASC 805-10 (on an asset acquisition), the Company recognizes the assets acquired, the liabilities assumed and any noncontrolling interest in the acquired entity at their relative fair values. The accounting provisions have also established that transaction costs associated with an asset acquisition are capitalized. Acquired in-place leases are valued as above-market or below-market as of the date of acquisition. The valuation is measured based on the present value (using an interest rate, which reflects the risks associated with the leases acquired) of the difference between (a) the contractual amounts to be paid pursuant to the in-place leases and (b) management’s estimate of fair market lease rates for the corresponding in-place leases over a period equal to the remaining non-cancelable term of the lease for above-market leases, taking into consideration below-market extension options for below-market leases. In addition, renewal options are considered and will be included in the valuation of in-place leases if (1) it is likely that the tenant will exercise the option, and (2) the renewal rent is considered to be sufficiently below a fair market rental rate at the time of renewal. The above-market and below-market lease values are capitalized as intangible lease assets or liabilities and amortized as an adjustment to rental income over the remaining terms of the respective leases. The aggregate relative fair value of in-place leases includes direct costs associated with obtaining a new tenant, opportunity costs associated with lost rentals, which are avoided by acquiring an in-place lease, and tenant relationships. Direct costs associated with obtaining a new tenant include commissions, tenant improvements, and other direct costs and are estimated using methods similar to those used in independent appraisals and management’s consideration of current market costs to execute a similar lease. These direct costs are considered intangible lease assets and are included with real estate assets on the consolidated balance sheets. The intangible lease assets are amortized to expense over the remaining terms of the respective leases. The value of opportunity costs is calculated using the contractual amounts to be paid, including real estate taxes, insurance, and other operating expenses, pursuant to the in-place leases over a market lease-up period for a similar lease. Customer relationships are valued based on management’s evaluation of certain characteristics of each tenant’s lease and the Company’s overall relationship with that respective tenant. Characteristics management will consider in allocating these values include the nature and extent of the Company’s existing business relationships with tenants, growth prospects for developing new business with the tenant, the tenant’s credit quality and expectations of lease renewals (including those existing under the terms of the lease agreement), among other factors. These intangibles will be included in intangible lease assets on the consolidated balance sheets and are amortized to expense over the remaining term of the respective leases. The determination of the relative fair values of the assets and liabilities acquired requires the use of significant assumptions about current market rental rates, rental growth rates, discount rates and other variables. Depreciation and Amortization The purchase price of real estate acquired and costs related to development, construction, and property improvements are capitalized. Repairs and maintenance costs include all costs that do not extend the useful life of the real estate asset and are expensed as incurred. The Company considers the period of future benefit of an asset to determine the appropriate useful life. The Company anticipates the estimated useful lives of its assets by class to be generally as follows: Buildings 25-40 years Building Improvements 5-20 years Land Improvements 15-25 years Tenant Improvements Shorter of estimated useful life or remaining contractual lease term Tenant Origination and Absorption Cost Remaining contractual lease term In-place Lease Valuation Remaining contractual lease term with consideration as to below-market extension options for below-market leases If a lease is terminated or amended prior to its scheduled expiration, the Company will accelerate the remaining useful life of the unamortized lease-related costs. Assets Held for Sale The Company accounts for properties held for sale in accordance with ASC 360, Property, Plant, and Equipment , (“ASC 360”), which addresses financial accounting and reporting for the impairment or disposal of long-lived assets and ASC 2014-08, Presentation of Financial Statements (“ASC 205”) and Property, Plant, and Equipment: Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (“ASU No. 2014-08”). Under ASU No. 2014-08, a discontinued operation is (i) a component of an entity or group of components that has been disposed of by sale, that has been disposed of other than by sale, or that is classified as held for sale that represents a strategic shift that has or will have a major effect on an entity’s operations and financial results or (ii) an acquired business or nonprofit activity that is classified as held for sale on the date of the acquisition. In accordance with ASC 205, a component of an entity or a group of components of an entity, or a business or nonprofit activity (the entity to be sold) shall be classified as held for sale in the period in which all of the required criteria are met. In accordance with ASC 360, upon being classified as held for sale, a property is carried at the lower of (i) its carrying amount or (ii) fair value less costs to sell. In addition, a property being held for sale ceases to be depreciated. Assets Reclassified from Held for Sale to Held and Used Upon the Company’s determination to discontinue marketing properties for sale, the properties will no longer meet the held for sale criteria and are required to be reclassified as held and used at the lower of adjusted carrying value (carrying value of the properties prior to being classified as held for sale adjusted for any depreciation and/or amortization expense that would have been recognized had the properties been continuously classified as held and used) or its fair value at the date of the subsequent decision not to sell. If adjusted carrying value is determined to be lower, a catch up adjustment will be recorded. The depreciation and/or amortization expenses that would have been recognized had the properties been continuously classified as held and used will be included as a component of depreciation and amortization expense in the accompanying consolidated statements of operations. If fair value is determined to be lower, the Company will record a loss included in income or loss from continuing operations in the accompanying consolidated statements of operations. Impairment of Real Estate and Related Intangible Assets The Company continually monitors events and changes in circumstances that could indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, including credit ratings of all tenants to stay abreast of any material changes in credit quality. The Company monitors tenant credit by (1) reviewing the credit ratings of tenants (or their parent companies or lease guarantors) that are rated by nationally recognized rating agencies; (2) reviewing financial statements and related metrics and information that are publicly available or that are required to be provided pursuant to the lease; (3) monitoring news reports and press releases regarding the tenants (or their parent companies or lease guarantors), and their underlying business and industry; and (4) monitoring the timeliness of rent collections. When indicators of potential impairment are present that indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, management assesses whether the carrying value of the assets will be recovered through the future undiscounted operating cash flows expected from the use of the assets and the eventual disposition. If, based on this analysis, the Company does not believe that it will be able to recover the carrying value of the asset, the Company will record an impairment charge to the extent the carrying value exceeds the net present value of the estimated future cash flows of the asset. Projections of expected future undiscounted cash flows require management to estimate future market rental income amounts subsequent to the expiration of current lease agreements, property operating expenses, discount rates, the number of months it takes to re-lease the property and the number of years the property is held for investment. As of December 31, 2017, the Company recorded an impairment provision of approximately $8.5 million related to the lease intangibles, building and land as it was determined that the carrying value of these assets would more than likely not be recoverable. Revenue Recognition Leases associated with the acquisition and contribution of certain real estate assets have net minimum rent payment increases during the term of the lease and are recorded to rental revenue on a straight-line basis, commencing as of the contribution or acquisition date. If a lease provides for contingent rental income, the Company will defer the recognition of contingent rental income, such as percentage rents, until the specific target that triggers the contingent rental income is achieved. Tenant reimbursement revenue, which is comprised of additional amounts collected from tenants for the recovery of certain operating expenses, including repair and maintenance, property taxes and insurance, and capital expenditures, to the extent allowed pursuant to the lease (collectively, “Recoverable Expenses”), is recognized as revenue when the additional rent is due. Recoverable Expenses to be reimbursed by a tenant are determined based on the Company’s estimate of the property’s operating expenses for the year, pro rated based on leased square footage of the property, and are collected in equal installments as additional rent from the tenant, pursuant to the terms of the lease. At the end of each quarter, the Company reconciles the amount of additional rent paid by the tenant during the quarter to the actual amount of the Recoverable Expenses incurred by the Company for the same period. The difference, if any, is either charged or credited to the tenant pursuant to the provisions of the lease. In certain instances, the lease may restrict the amount the Company can recover from the tenant such as a cap on certain or all property operating expenses. In a situation in which a lease associated with a significant tenant has been, or is expected to be, terminated early, or extended, the Company evaluates the remaining useful life of amortizable assets in the asset group related to the lease that will be terminated (i.e., above- and below-market lease intangibles, in-place lease value and deferred leasing costs). Based upon consideration of the facts and circumstances surrounding the termination or extension, the Company may write-off or accelerate the amortization associated with the asset group. Such amounts are included within rental and other income for above- and below-market lease intangibles and amortization for the remaining lease related asset groups in the consolidated statements of operations. Derivative Instruments and Hedging Activities FASB ASC 815: Derivatives and Hedging (“ASC 815”) provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, ASC 815 requires qualitative disclosures regarding the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company recorded all derivatives on the consolidated balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, and whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. See Note 6, Interest Rate Contracts . Income Taxes The Company has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). To qualify as a REIT, the Company must meet certain organizational and operational requirements. The Company intends to adhere to these requirements and maintain its REIT status for the current year and subsequent years. As a REIT, the Company generally will not be subject to federal income taxes on taxable income that is distributed to stockholders. However, the Company may be subject to certain state and local taxes on its income and property, and federal income and excise taxes on its undistributed taxable income, if any. If the Company fails to qualify as a REIT in any taxable year, the Company will then be subject to federal income taxes on the taxable income at regular corporate rates and will not be permitted to qualify for treatment as a REIT for federal income tax purposes for four years following the year during which qualification is lost unless the Internal Revenue Service (“IRS”) grants the Company relief under certain statutory provisions. Such an event could materially adversely affect net income and net cash available for distribution to stockholders. As of December 31, 2017 , the Company satisfied the REIT requirements and distributed all of its taxable income. Pursuant to the Code, the Company has elected to treat its corporate subsidiary as a TRS. In general, the TRS may perform non-customary services for the Company’s tenants and may engage in any real estate or non real estate-related business. The TRS will be subject to corporate federal and state income tax. As of December 31, 2017 , the TRS had not commenced operations. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Change in Consolidated Financial Statements Presentation Certain amounts in the Company’s prior period consolidated financial statements have been reclassified to conform to the current period presentation. Property expense recovery reimbursements are presented gross on the statement of operations for all periods presented. During the year ended December 31, 2017, the Company elected to early adopt ASU No. 2016-18 (as defined below). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the consolidated statements of cash flows. Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding, including common stock equivalents. As of December 31, 2017 and December 31, 2016 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders. Segment Information Segment Reporting (“ ASC 280 ”) , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment. Unaudited Data Any references to the number of buildings, square footage, number of leases, occupancy, and any amounts derived from these values in the notes to the consolidated financial statements are unaudited and outside the scope of the Company’s independent registered public accounting firm’s audit of its consolidated financial statements in accordance with the standards of the Public Company Accounting Oversight Board (“PCAOB”). Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging. 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. The ASU is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. For cash flow hedges in existence at the date of adoption, an entity is required to apply a cumulative-effect adjustment for previously recognized ineffectiveness from retained earnings to accumulated other comprehensive income, as of the beginning of the fiscal year when an entity adopts the amendments in this ASU. The Company utilizes interest rate hedge agreements to hedge a portion of exposure to variable interest rates primarily associated with borrowings based on London Interbank Offered Rate (“LIBOR”). As a result, all interest rate hedge agreements are designated as cash flow hedges. During the years ended December 31, 2017 and 2016, the ineffectiveness related to the Company’s interest rate hedge agreements was immaterial. Therefore, the Company does not believe this ASU would have an impact on operating results for the year ended December 31, 2017 . In January 2017, the FASB issued ASU No. 2017-01, Business Combinations, that clarified the definition of a business. The ASU is effective for reporting periods beginning after December 15, 2017, with early adoption permitted. The Company adopted this update on January 1, 2017. Refer to “ Real Estate Purchase Price Allocation ” above for a discussion of this accounting pronouncement. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , that will require companies to include restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The ASU will require a disclosure of a reconciliation between the statement of financial position and the statement of cash flows when the statement of financial position includes more than one line item for cash, cash equivalents, restricted cash, and restricted cash equivalents. Entities with material restricted cash and restricted cash equivalents balances will be required to disclose the nature of the restrictions. This ASU is effective for reporting periods beginning after December 15, 2017, with early adoption permitted, and will be applied retrospectively to all periods presented. The Company elected to early adopt ASU No. 2016-18 for the reporting period ending December 31, 2017 and apply this ASU retrospectively to all periods presented. As a result of the adoption of ASU No. 2016-18, the Company no longer presents the changes within restricted cash in the consolidated statements of cash flows. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments . ASU No. 2016-15 addresses eight specific cash flow issues with the objective of reducing diversity in practice. The cash flow issues include debt prepayment or debt extinguishment costs and proceeds from the settlement of insurance claims. This ASU is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The Company elected to early adopt ASU No. 2016-15 for the reporting period ending December 31, 2017. There was no change to the Company’s consolidated financial statements or notes as a result of adoption. In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU No. 2016-02”). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued a proposed amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which allows for (a) an entity need not to reassess whether any expired or existing contracts are or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in board meeting minutes of May 2017 that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In January, 2018, the FASB issued a proposed amendment to ASU No. 2016-02 that would all

Real Estate

Real Estate	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Real Estate [Line Items]
Real Estate	Real Estate As of September 30, 2018 , the Company's real estate portfolio consisted of 27 properties ( 35 buildings) in 17 states consisting of office, industrial, distribution, and data center facilities with a combined acquisition value of $1.1 billion including the allocation of the purchase price to above and below-market lease valuation, encompassing approximately 7.3 million square feet. Depreciation expense for buildings and improvements for the nine months ended September 30, 2018 was $ 15.3 million . Amortization expense for intangibles, including, but not limited to, tenant origination and absorption costs, for the nine months ended September 30, 2018 was $ 18.1 million . Future Minimum Contractual Rent Payments The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company's current leases have expirations ranging from 2021 to 2044. As of September 30, 2018 Remaining 2018 $ 19,311 2019 78,887 2020 80,492 2021 72,677 2022 73,538 Thereafter 528,803 Total $ 853,708 Intangibles The Company allocated a portion of the acquired real estate asset value to in-place lease valuation and tenant origination and absorption cost. The in-place lease was measured against comparable leasing information and the present value of the difference between the contractual, in-place rent and the fair market rent was calculated using, as the discount rate, the capitalization rate utilized to compute the value of the real estate at acquisition. September 30, 2018 December 31, 2017 In-place lease valuation (above market) $ 4,046 $ 4,046 In-place lease valuation (above market), accumulated amortization (1,030 ) (752 ) Intangible assets, net $ 3,016 $ 3,294 In-place lease valuation (below market) $ (62,070 ) $ (62,070 ) In-place lease valuation (below market) - accumulated amortization 14,564 10,775 In-place lease valuation (below market), net $ (47,506 ) $ (51,295 ) Tenant origination and absorption cost $ 240,364 $ 240,364 Tenant origination and absorption cost - accumulated amortization (65,264 ) (47,165 ) Tenant origination and absorption cost, net $ 175,100 $ 193,199 The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, and tenant origination and absorption costs as of September 30, 2018 for the next five years : Year In-Place Lease Valuation Tenant Origination and Absorption Costs Remaining 2018 $ (1,170 ) $ 6,033 2019 $ (4,695 ) $ 24,198 2020 $ (4,695 ) $ 24,198 2021 $ (3,799 ) $ 19,715 2022 $ (3,799 ) $ 19,597	Real Estate As of December 31, 2017 , the Company’s real estate portfolio consisted of 27 properties ( 35 buildings) in 17 states consisting of office, industrial, distribution, and data center facilities with a combined acquisition value of $1.1 billion including the allocation of the purchase price to above and below-market lease valuation, encompassing approximately 7.3 million square feet. Depreciation expense for buildings and improvements for the year ended December 31, 2017 was $ 20.2 million . Amortization expense for intangibles, including, but not limited to, tenant origination and absorption costs, for the year ended December 31, 2017 was $ 23.8 million . The purchase price and other acquisition items for the properties acquired during the year ended December 31, 2017 are shown below: Paid to Advisor Property Location Tenant/Major Lessee Acquisition Date Purchase Price Approx. Square Feet Acquisition Fees and Reimbursable Expenses (1) Contingent Advisor Payment (2) Year of Lease Expiration Allstate Lone Tree, CO Allstate Insurance Company 1/31/2017 $ 14,750 (3) 70,300 $ 402 $ 273 2026 MISO Carmel, IN Midcontinent Independent System Operator, Inc. 5/15/2017 $ 28,600 133,400 $ 696 $ 529 2028 (1) Under the Original Advisory Agreement, the fee consisted of a 2.0% base acquisition fee and acquisition expense reimbursement for actual acquisition expenses incurred, estimated to be approximately 1.0% of acquisition value. (2) Under the Original Advisory Agreement, the Advisor was entitled to receive an acquisition fee in an amount up to 3.85% of the contract purchase price for each property the Company acquired. The acquisition fee consisted of a 2.0% base acquisition fee and up to an additional 1.85% contingent advisor payment (the “Contingent Advisor Payment”); provided, however, that $5.0 million of amounts advanced by the Advisor for dealer manager fees and organizational and offering expenses (the “Contingent Advisor Payment Holdback”) would be retained by the Company until the later of (a) the termination of the IPO, including any follow-on offerings where the Advisor provides up-front funding of offering fees, or (b) July 31, 2017, at which time such amount would be paid to the Advisor. On July 31, 2017, the Company paid to the Advisor the Contingent Advisor Payment Holdback of $5.0 million , which consisted of amounts previously advanced by the Advisor for dealer manager fees and organizational and offering expenses. (3) The purchase price for the Allstate property was $14.8 million , plus closing costs, less a credit in the amount of $0.4 million applied at closing. Real Estate - Valuation and Purchase Price Allocation The Company allocates the purchase price to the fair value of the tangible assets of a property by valuing the property as if it were vacant. This “as-if vacant” value is estimated using an income, or discounted cash flow, approach that relies upon Level 3 inputs, which are unobservable inputs based on the Company’s review of the assumptions a market participant would use. These Level 3 inputs include discount rates, capitalization rates, market rents and comparable sales data for similar properties. Estimates of future cash flows are based on a number of factors including historical operating results, known and anticipated trends, and market and economic conditions. In calculating the “as-if vacant” value for acquisitions completed during the year ended December 31, 2017 , the Company used discount rates ranging from 5.75% to 8.25% . In determining the fair value of intangible lease assets or liabilities, the Company also considers Level 3 inputs. Acquired above and below-market leases are valued based on the present value of the difference between prevailing market rates and the in-place rates measured over a period equal to the remaining term of the lease for above-market leases and the initial term plus the term of any below-market fixed rate renewal options for below-market leases, if applicable. The estimated fair value of acquired in-place at-market tenant leases are the costs that would have been incurred to lease the property to the occupancy level of the property at the date of acquisition. Such estimates include the value associated with leasing commissions, legal and other costs, as well as the estimated period necessary to lease such property that would be incurred to lease the property to its occupancy level at the time of its acquisition. Acquisition costs associated with asset acquisitions are capitalized in the period they are incurred. The following summarizes the purchase price allocations for the properties acquired during the year ended December 31, 2017 : Property (1) Land Building and Improvements Tenant Origination and Absorption Cost In-Place Lease Valuation Above Market In-Place Lease Valuation (Below) Market Total Allstate $ 1,808 $ 9,071 $ 5,019 $ — $ (1,001 ) $ 14,897 MISO $ 3,104 $ 18,077 $ 7,937 $ 218 $ — $ 29,336 (1) The Company evaluated the transactions above under the clarified framework for determining whether an integrated set of assets and activities meets the definition of a business, pursuant to ASU No. 2017-01, Business Combinations, issued in January 2017, which the Company early-adopted effective October 1, 2016. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. Since the transactions above lacked a substantive process, the transactions did not meet the definition of a business and consequently were accounted for as asset acquisitions. The Company allocated the total consideration (including acquisition costs of approximately $1.2 million ) to the individual assets and liabilities acquired on a relative fair value basis. Future Minimum Contractual Rent Payments The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company’s current leases have expirations ranging from 2020 to 2044. As of December 31, 2017 2018 $ 71,662 2019 78,887 2020 80,492 2021 72,677 2022 73,538 Thereafter 528,803 Total $ 906,059 Intangibles The Company allocated a portion of the acquired real estate asset value to in-place lease valuation and tenant origination and absorption cost. The in-place lease was measured against comparable leasing information and the present value of the difference between the contractual, in-place rent and the fair market rent was calculated using, as the discount rate, the capitalization rate utilized to compute the value of the real estate at acquisition. The intangible assets are amortized over the remaining lease terms of the respective properties, which on a weighted-average basis, was approximately 10.3 and 11.4 years as of December 31, 2017 and December 31, 2016 , respectively. December 31, 2017 December 31, 2016 In-place lease valuation (above market) $ 4,046 $ 3,828 In-place lease valuation (above market), accumulated amortization (752 ) (300 ) Intangible assets, net $ 3,294 $ 3,528 In-place lease valuation (below market) $ (62,070 ) $ (61,069 ) In-place lease valuation (below market) - accumulated amortization 10,775 5,750 In-place lease valuation (below market), net $ (51,295 ) $ (55,319 ) Tenant origination and absorption cost $ 240,364 $ 227,407 Tenant origination and absorption cost - accumulated amortization (47,165 ) (23,409 ) Tenant origination and absorption cost, net $ 193,199 $ 203,998 The amortization of the intangible assets and other leasing costs for the respective periods is as follows: Amortization (income) expense for the year ended December 31, 2017 2016 2015 In-place lease valuation $ (4,573 ) $ (3,592 ) $ (1,858 ) Tenant origination and absorption cost $ 23,756 $ 16,264 $ 7,145 The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, and tenant origination and absorption costs as of December 31, 2017 for the next five years: Year In-Place Lease Valuation Tenant Origination and Absorption Costs 2018 $ (4,695 ) $ 24,198 2019 $ (4,695 ) $ 24,198 2020 $ (4,695 ) $ 24,198 2021 $ (3,799 ) $ 19,715 2022 $ (3,799 ) $ 19,597
Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Real Estate	Real Estate As of September 30, 2018 , the Company’s real estate portfolio consisted of 76 properties in 20 states consisting substantially of office, warehouse, and manufacturing facilities and two land parcels held for future development with a combined acquisition value of approximately $3.0 billion , including the allocation of the purchase price to above and below-market lease valuation. Depreciation expense for buildings and improvements for the nine months ended September 30, 2018 was $44.4 million . Amortization expense for intangibles, including, but not limited to, tenant origination and absorption costs for the nine months ended September 30, 2018 was $44.9 million . 2018 Acquisitions The purchase price and other acquisition items for the properties acquired during the nine months ended September 30, 2018 are shown below: Property Location Tenant/Major Lessee Acquisition Date Purchase Price Approx. Square Feet Acquisition Fees and Expenses (1) Year of Lease Expiration Quaker Lakeland, Florida Quaker Sales and Distribution, Inc. 3/13/2018 $ 59,600 605,400 $ 1,777 2028 McKesson Scottsdale, Arizona McKesson Corporation 4/10/2018 $ 67,000 271,100 $ 2,139 2028 Shaw Wentworth, Georgia Shaw Industries, Inc. 5/3/2018 $ 56,526 1,001,500 $ 1,782 2033 (1) The Advisor is entitled to receive acquisition fees equal to 2.5% and acquisition expense reimbursement of up to 0.5% of the contract purchase price for each acquisition. In addition, the Company incurred third-party costs associated with the three acquisitions. Real Estate - Valuation and Purchase Price Allocation The Company allocates the purchase price to the relative fair value of the tangible assets of a property by valuing the property as if it were vacant. This “as-if vacant” value is estimated using an income, or discounted cash flow, approach that relies upon Level 3 inputs, which are unobservable inputs based on the Company's review of the assumptions a market participant would use. These Level 3 inputs include discount rates, capitalization rates, market rents and comparable sales data for similar properties. Estimates of future cash flows are based on a number of factors including historical operating results, known and anticipated trends, and market and economic conditions. In calculating the “as-if vacant” value for acquisitions completed during the nine months ended September 30, 2018 , the Company used a discount rate of 6.25% to 7.75% . In determining the fair value of intangible lease assets or liabilities, the Company also considers Level 3 inputs. Acquired above and below-market leases are valued based on the present value of the difference between prevailing market rates and the in-place rates measured over a period equal to the remaining term of the lease for above-market leases and the initial term plus the term of any below-market fixed rate renewal options for below-market leases, if applicable. The estimated fair value of acquired in-place at-market tenant leases are the costs that would have been incurred to lease the property to the occupancy level of the property at the date of acquisition. Such estimates include the value associated with leasing commissions, legal and other costs, as well as the estimated period necessary to lease such property that would be incurred to lease the property to its occupancy level at the time of its acquisition. Acquisition costs associated with asset acquisitions are capitalized in the period they are incurred. The following summarizes the purchase price allocations of the properties acquired during the nine months ended September 30, 2018 : Property (1) Land Building and improvements Tenant origination and absorption costs In-place lease valuation - above (below) market Receivable- Ground Lease Payable- Ground Lease Payments Total Quaker $ 5,433 $ 50,953 $ 4,387 $ (502 ) $ — $ — $ 60,271 McKesson $ 312 $ 45,109 $ 24,652 $ (933 ) $ — $ — $ 69,140 Shaw $ 5,465 $ 48,820 $ 8,297 $ (4,273 ) $ 2,008 $ (2,008 ) $ 58,309 (1) The Company evaluated the transactions above under the clarified framework for determining whether an integrated set of assets and activities meets the definition of a business, pursuant to ASU No. 2017-01, Business Combinations, issued in January 2017, which the Company early-adopted effective January 1, 2017. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. Since the transactions above lacked a substantive process, the transactions did not meet the definition of a business and consequently were accounted for as asset acquisitions. The Company allocated the total consideration (including acquisition costs of approximately $5.7 million ) to the individual assets and liabilities acquired on a relative fair value basis. Future Minimum Contractual Rent Payments The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company's current leases have expirations ranging from 2018 to 2036. As of September 30, 2018 Remaining 2018 $ 61,164 2019 226,557 2020 204,640 2021 191,182 2022 182,708 Thereafter 803,849 Total $ 1,670,100 Intangibles The Company allocated a portion of the acquired and contributed real estate asset value to in-place lease valuation and tenant origination and absorption cost, net of the write-off of intangibles, as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 In-place lease valuation (above market) $ 42,736 $ 42,736 In-place lease valuation (above market) - accumulated amortization (31,065 ) (26,613 ) In-place lease valuation (above market), net 11,671 16,123 Ground leasehold interest (below market) 2,254 2,255 Ground leasehold interest (below market) - accumulated amortization (129 ) (109 ) Ground leasehold interest (below market), net 2,125 2,146 Intangible assets, net $ 13,796 $ 18,269 In-place lease valuation (below market) $ (55,482 ) $ (49,774 ) In-place lease valuation (below market) - accumulated amortization 30,779 26,193 In-place lease valuation (below market), net $ (24,703 ) $ (23,581 ) Tenant origination and absorption cost $ 532,207 $ 494,871 Tenant origination and absorption cost - accumulated amortization (284,763 ) (242,108 ) Tenant origination and absorption cost, net $ 247,444 $ 252,763 The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, net, tenant origination and absorption costs, ground leasehold improvements, and other leasing costs as of September 30, 2018 for the next five years: Year In-place lease valuation, net Tenant origination and absorption costs Ground leasehold improvements Other leasing costs Remaining 2018 $ (386 ) $ 11,150 $ 21 $ 2,389 2019 $ (2,464 ) $ 38,096 $ 21 $ 4,765 2020 $ (936 ) $ 29,867 $ 21 $ 4,712 2021 $ (717 ) $ 25,170 $ 21 $ 4,830 2022 $ (1,058 ) $ 22,938 $ 21 $ 4,818 Tenant and Portfolio Risk The Company monitors the credit of all tenants to stay abreast of any material changes in credit quality. The Company monitors tenant credit by (1) reviewing the credit ratings of tenants (or their parent companies) that are rated by nationally recognized rating agencies; (2) reviewing financial statements and related metrics and information that are publicly available or that are required to be provided pursuant to the lease; (3) monitoring news reports and press releases regarding the tenants and their underlying business and industry; and (4) monitoring the timeliness of rent collections. Restricted Cash In conjunction with acquisition of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash. Additionally, an ongoing replacement reserve is funded by certain tenants pursuant to each tenant’s respective lease as follows: Balance as of September 30, 2018 December 31, 2017 Cash reserves $ 20,619 $ 17,034 Midland mortgage loan restricted lockbox 1,746 2,158 1031 Exchange Funds (1) — 154,940 Total $ 22,365 $ 174,132 (1) Section 1031 of the Internal Revenue Code of 1986, as amended ("1031 Exchanges"). Represents cash proceeds from a disposition that are temporarily held at the qualified intermediary for purposes of facilitating potential Section 1031 Exchanges. The Company's three acquisitions during the six months ended June 30, 2018 completed the 1031 Exchange. As of September 30, 2018 , one property, the Bridgestone property located in Bloomingdale, Illinois, met the criteria to be classified as held for sale. Therefore, the Company classified the property as held for sale, net, on the consolidated balance sheets at the lower of its (i) carrying amount or (ii) fair value less disposition costs as of September 30, 2018 . The Bridgestone property is included in continuing operations in the consolidated statements of operations, as the property did not meet the prerequisite requirements to be classified as a discontinued operation. The following summary presents the major components of assets and liabilities related to the real estate held for sale as of the nine months ended September 30, 2018 and year ended December 31, 2017 : Balance as of September 30, 2018 December 31, 2017 Land $ 589 $ 589 Building and improvements 2,493 2,493 Tenant origination and absorption cost 493 493 Total real estate 3,575 3,575 Less: accumulated depreciation and amortization (868 ) (794 ) Total real estate, net 2,707 2,781 Other assets 4 178 Total assets $ 2,711 $ 2,959 Accrued expenses and other liabilities $ 288 $ 527 Due to affiliates 5 10 Total liabilities $ 293 $ 537	Real Estate As of December 31, 2017 , the Company’s real estate portfolio consisted of 73 properties in 20 states consisting substantially of office, warehouse, and manufacturing facilities and 2 land parcels held for future development with a combined acquisition value of approximately $2.8 billion , including the allocation of the purchase price to above and below-market lease valuation. Depreciation expense for buildings and improvements for the years ended December 31, 2017 , 2016 , and 2015 was $56.0 million , $56.7 million , and $43.3 million , respectively. Amortization expense for intangibles, including but not limited to, tenant origination and absorption costs for the years ended December 31, 2017 , 2016 , and 2015 was $60.6 million , $74.1 million , and $69.4 million , respectively. 2017 Acquisitions The purchase price and other acquisition items for the property acquired during the year ended December 31, 2017 are shown below: Property Location Tenant/Major Lessee Acquisition Date Purchase Price Approx. Square Feet Acquisition Fees Paid to the Advisor (1) Year of Lease Expiration LPL Fort Mill, SC LPL Holdings, Inc. 11/30/2017 $ 130,000 451,600 $ 3,791 2036 (1) The Advisor is entitled to receive acquisition fees equal to 2.5% and acquisition expense reimbursement of up to 0.5% of the contract purchase price for each acquisition. Real Estate - Valuation and Purchase Price Allocation The Company allocates the purchase price to the relative fair value of the tangible assets of a property by valuing the property as if it were vacant. This “as-if vacant” value is estimated using an income, or discounted cash flow, approach that relies upon Level 3 inputs, which are unobservable inputs based on the Company’s review of the assumptions a market participant would use. These Level 3 inputs include discount rates, capitalization rates, market rents and comparable sales data for similar properties. Estimates of future cash flows are based on a number of factors including historical operating results, known and anticipated trends, and market and economic conditions. In calculating the “as-if vacant” value for acquisitions completed during the year ended December 31, 2017 , the Company used a discount rate of 7% . In determining the fair value of intangible lease assets or liabilities, the Company also considers Level 3 inputs. Acquired above and below-market leases are valued based on the present value of the difference between prevailing market rates and the in-place rates measured over a period equal to the remaining term of the lease for above-market leases and the initial term plus the term of any below-market fixed rate renewal options for below-market leases, if applicable. The estimated fair value of acquired in-place at-market tenant leases are the costs that would have been incurred to lease the property to the occupancy level of the property at the date of acquisition. Such estimates include the value associated with leasing commissions, legal and other costs, as well as the estimated period necessary to lease such property that would be incurred to lease the property to its occupancy level at the time of its acquisition. Acquisition costs associated with asset acquisitions are capitalized in the period they are incurred. The following summarizes the purchase price allocation of the LPL property acquired during the year ended December 31, 2017 : Property Land Building and improvements Tenant origination and absorption costs In-place lease valuation - above market Total LPL (1) $ 5,886 $ 108,000 $ 19,859 $ 383 $ 134,128 (1) The Company evaluated the transactions above under the clarified framework for determining whether an integrated set of assets and activities meets the definition of a business, pursuant to ASU No. 2017-01, Business Combinations, issued in January 2017, which the Company early-adopted effective January 1, 2017. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. Since the transaction above lacked a substantive process, the transaction did not meet the definition of a business and consequently was accounted for as asset acquisition. The Company allocated the total consideration (including acquisition costs of approximately $4.1 million ) to the individual assets and liabilities acquired on a relative fair value basis. Sale of Properties 12669 Encinitas Avenue (“ITT Property”) On June 30, 2017, the Company sold the ITT property located in Los Angeles, California for total proceeds of $10.0 million , less closing costs and other closing credits. The carrying value of the property on the closing date was approximately $5.4 million . Upon the sale of the property, the Company recognized a gain of approximately $4.0 million . 26 Century Boulevard (“One Century Plaza Property”) On October 19, 2017, the Company sold the One Century Plaza property located in Nashville, Tennessee for total proceeds of $100.0 million , less closing costs and other closing credits. The carrying value of the property on the closing date was approximately $67.9 million . Upon the sale of the property, the Company recognized a gain of approximately $32.1 million . 910 Flower Street (“DreamWorks Property”) On November 20, 2017, the Company sold the DreamWorks property located in Los Angeles, California for total proceeds of $290.0 million , less closing costs and other closing credits. The carrying value of the property on the closing date was approximately $210.1 million . Upon the sale of the property, the Company recognized a gain of approximately $79.9 million . Future Minimum Contractual Rent Payments The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company’s current leases have expirations ranging from 2018 to 2036. As of December 31, 2017 2018 $ 231,620 2019 210,449 2020 188,653 2021 174,053 2022 164,494 Thereafter 664,226 Total $ 1,633,495 Intangibles The Company allocated a portion of the acquired and contributed real estate asset value to in-place lease valuation and tenant origination and absorption cost, net of the write-off of intangibles for the years ended December 31, 2017 and 2016 . In-place leases were measured against comparable leasing information and the present value of the difference between the contractual, in-place rent, and the fair market rent was calculated using, as the discount rate, the capitalization rate utilized to compute the value of the real estate at acquisition or contribution. December 31, 2017 2016 In-place lease valuation (above market) $ 43,826 $ 47,419 In-place lease valuation (above market) - accumulated amortization (27,703 ) (20,543 ) In-place lease valuation (above market), net 16,123 26,876 Ground leasehold interest (below market) 2,255 2,254 Ground leasehold interest (below market) - accumulated amortization (109 ) (82 ) Ground leasehold interest (below market), net 2,146 2,172 Intangible assets, net $ 18,269 $ 29,048 In-place lease valuation (below market) $ (49,774 ) $ (51,966 ) In-place lease valuation (below market) - accumulated amortization 26,193 20,330 In-place lease valuation (below market), net $ (23,581 ) $ (31,636 ) Tenant origination and absorption cost $ 495,364 $ 541,646 Tenant origination and absorption cost - accumulated amortization (242,601 ) (197,173 ) Tenant origination and absorption cost, net $ 252,763 $ 344,473 The intangible assets are amortized over the remaining lease term of each property, which on a weighted-average basis, was approximately 6.5 years and 7.1 years as of December 31, 2017 and 2016 , respectively. The amortization of the intangible assets and other leasing costs for the respective periods is as follows: Amortization (income) expense for the year ended December 31, 2017 2016 2015 In-place lease valuation, net $ 1,689 $ 3,287 $ (3,785 ) Tenant origination and absorption cost $ 59,046 $ 72,912 $ 69,099 Ground leasehold amortization (below market) $ 27 $ 28 $ 28 Other leasing costs amortization $ 1,527 $ 1,202 $ 301 The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, net, tenant origination and absorption costs, ground leasehold improvements, and other leasing costs as of December 31, 2017 for the next five years: Year In-place lease valuation, net Tenant origination and absorption costs Ground leasehold improvements Other leasing costs 2018 $ (1,018 ) $ 51,363 $ 27 $ 1,768 2019 $ (1,856 ) $ 42,721 $ 27 $ 1,782 2020 $ (770 ) $ 33,302 $ 27 $ 1,757 2021 $ (630 ) $ 28,724 $ 27 $ 1,704 2022 $ (1,007 ) $ 24,918 $ 27 $ 1,674 Tenant and Portfolio Risk The Company monitors the credit of all tenants to stay abreast of any material changes in credit quality. The Company monitors tenant credit by (1) reviewing the credit ratings of tenants (or their parent companies) that are rated by nationally recognized rating agencies; (2) reviewing financial statements and related metrics and information that are publicly available or that are required to be provided pursuant to the lease; (3) monitoring news reports and press releases regarding the tenants and their underlying business and industry; and (4) monitoring the timeliness of rent collections. 2500 Windy Ridge Parkway In January 2017, Coca-Cola Refreshments USA, Inc. terminated their lease at the 2500 Windy Ridge Parkway property located in Atlanta, Georgia (an office facility); consequently, the Company released Coca-Cola Refreshments USA, Inc. from any and all obligations under the lease in-place effective December 31, 2016. In exchange, the Company agreed to receive a fee of $12.8 million , which is included in lease termination income on the consolidated statements of operations for the year ended December 31, 2017 . The fee is being paid in quarterly installments over a two year period equal to $1.6 million per quarter. The Company received the first payment on January 31, 2017. During the year ended December 31, 2016 , and as a result of the lease termination, the Company accelerated approximately $3.4 million of unamortized in-place lease intangible assets that were recorded as part of the purchase price allocation when the property was acquired and approximately $0.4 million of deferred rent. 400 Bertha Lamme Drive During the year ended December 31, 2017 , as a result of Westinghouse Electric Company, LLC filing for bankruptcy, the Company recorded an impairment provision of approximately $5.7 million related to the lease intangibles as it was determined that the carrying value of these assets would not be recoverable, which excluded building and land. In determining the fair value of intangible lease assets, the Company considered Level 3 inputs. The estimated fair value of acquired in-place at-market tenant leases are the costs that would have been incurred to lease the property to the occupancy level of the property at the date of acquisition. Such estimates include the value associated with leasing commissions, legal and other costs, as well as the estimated period necessary to lease such property that would be incurred to lease the property to its occupancy level at the time of its acquisition. 333 East Lake Street During the year ended December 31, 2017 , the Company recorded an impairment provision of approximately $2.8 million as it was determined that the carrying value of the real estate would not be recoverable. This impairment resulted from changes in projected cash flows the property was expected to generate. In determining the fair value of property, the Company considered Level 3 inputs. Restricted Cash In conjunction with acquisition of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash. Additionally, an ongoing replacement reserve is funded by certain tenants pursuant to each tenant’s respective lease as follows: Balance as of December 31, 2016 Additions Deductions Balance as of December 31, 2017 Tenant improvement reserves (1) $ 9,238 $ 5,468 $ (1,071 ) $ 13,635 Midland mortgage loan repairs reserves (2) 67 323 — 390 Real estate tax reserve (3) 1,645 3,344 (2,892 ) 2,097 Property insurance reserve (Emporia Partners) (3) 257 467 (499 ) 225 Rent Abatement Reserve — 731 (390 ) 341 Restricted deposits/Leasing commission reserve 745 4 (404 ) 345 Midland mortgage loan restricted lockbox (4) 1,468 2,158 (1,468 ) 2,158 Holdback Escrow (5) — 77,275 (77,275 ) — 1031 Exchange Funds (6) — 286,711 (131,771 ) 154,940 Total $ 13,420 $ 376,481 $ (215,770 ) $ 174,131 (1) Represents tenant improvement reserves held by the lenders. (2) Represents a deferred maintenance reserve funded by the Company as part of the refinancing that occurred on February 28, 2013, whereby certain properties became collateral for the Midland mortgage loan. (3) Represents real estate tax and insurance reserves which are funded monthly and held by the lenders. Funds are requested for disbursement as real estate tax and insurance premium payments are made. (4) As part of the terms of the Midland mortgage loan, rent collections from the eight properties which serve as collateral thereunder are received in a designated cash collateral account which is controlled by the lender until the designated payment date, as defined in the loan agreement, and the excess cash is transferred to the operating account. (5) Represents initial funds held back related to the Bank of America Loan, which were released on October 25, 2017 and October 26, 2017. (6) Represents cash proceeds from a disposition that are temporarily held at the qualified intermediary for purposes of facilitating potential Section 1031 Exchanges.

Investments

Investments	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Griffin Capital Essential Asset REIT, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Investments	Investments Investment in Unconsolidated Entities Heritage Commons X, LTD In June 2018, the Company, through a special purpose entity, wholly-owned by the Operating Partnership, formed a joint venture (the "Heritage Common X") for the construction and ownership of a four-story Class "A" office building with a net rentable area of approximately 200,000 square feet located in Forth Worth Texas (the "Heritage Commons Property"). The Heritage Commons Property is expected to be completed in January 2019 and is 100% leased to Mercedes-Benz Financial Services USA. The total project budget is $48.1 million , which was funded via a $41.4 million construction loan, and approximately $6.7 million of equity contributed by the members of the joint venture. As of September 30, 2018 , the Company has an ownership interest of approximately 45% in the Heritage Common X joint venture. The Company's equity contributions consisted of $3.1 million , provided during the initial creation of Heritage Common X. Digital Realty Trust, Inc. In September 2014, the Company, through a special purpose entity ("SPE"), wholly-owned by the Operating Partnership, acquired an 80% interest in a joint venture with an affiliate of Digital Realty Trust, Inc. for $68.4 million , which was funded with equity proceeds raised in the Company's Public Offerings. The gross acquisition value of the property was $187.5 million , plus closing costs, which was partially financed with debt of $102.0 million . The joint venture was created for purposes of directly or indirectly acquiring, owning, financing, operating and maintaining a data center facility located in Ashburn, Virginia (the "Property"). The Property is approximately 132,300 square feet and consists of certain data processing and communications equipment that is fully leased to a social media company and a financial services company with an average remaining lease term of approximately four years . The joint venture currently uses an interest rate swap to manage its interest rate risk associated with its variable rate debt. The interest rate swap is designated as an interest rate hedge of its exposure to the volatility associated with interest rates. As a result of the hedge designation and in satisfying the requirement for cash flow hedge accounting, the joint venture records changes in the fair value in accumulated other comprehensive income. In conjunction with the investment in the joint venture discussed above, the Company recognized its 80% share, or approximately $0.2 million of other comprehensive income for the nine months ended September 30, 2018 . The interests discussed above are deemed to be variable interests in variable interest entities ("VIE') and, based on an evaluation of the variable interests against the criteria for consolidation, the Company determined that it is not the primary beneficiary of the investments, as the Company does not have power to direct the activities of the entities that most significantly affect their performance. As such, the interest in the VIEs are recorded using the equity method of accounting in the accompanying consolidated financial statements. Under the equity method, the investments in the unconsolidated entities are stated at cost and adjusted for the Company’s share of net earnings or losses and reduced by distributions. Equity in earnings of real estate ventures is generally recognized based on the allocation of cash distributions upon liquidation of the investment at book value in accordance with the operating agreements. The Company's maximum exposure to losses associated with their unconsolidated investments is primarily limited to its carrying value in the investments. As of September 30, 2018 , the balance of the investments are shown below: Digital Realty Joint Venture Heritage Common X Total Balance as of December 31, 2017 $ 37,114 $ — $ 37,114 Initial contribution — 3,266 3,266 Net loss (1,617 ) — (1,617 ) Distributions (5,627 ) — (5,627 ) Other comprehensive income 224 — 224 Balance as of September 30, 2018 $ 30,094 $ 3,266 $ 33,360	Investments Investment in Unconsolidated Entities Digital Realty Trust, Inc. On September 9, 2014, the Company, through a special purpose entity (“SPE”), wholly-owned by the Operating Partnership, acquired an 80% interest in a joint venture with an affiliate of Digital Realty Trust, Inc. for $68.4 million , which was funded with equity proceeds raised in the Company’s Public Offerings. The gross acquisition value of the property was $187.5 million , plus closing costs, which was partially financed with debt of $102.0 million . The joint venture was created for purposes of directly or indirectly acquiring, owning, financing, operating and maintaining a data center facility located in Ashburn, Virginia (the “Property”). The Property is approximately 132,300 square feet and consists of certain data processing and communications equipment that is fully leased to a social media company and a financial services company with an average remaining lease term of approximately five years . The joint venture currently uses an interest rate swap to manage its interest rate risk associated with its variable rate debt. The interest rate swap is designated as an interest rate hedge of its exposure to the volatility associated with interest rates. As a result of the hedge designation and in satisfying the requirement for cash flow hedge accounting, the joint venture records changes in the fair value in accumulated other comprehensive income. In conjunction with the investment in the joint venture discussed above, the Company recognized its 80% share, or approximately $0.5 million of other comprehensive income for the year ended December 31, 2017 . The interest discussed above is deemed to be a variable interest in a VIE, and, based on an evaluation of the variable interest against the criteria for consolidation, the Company determined that it is not the primary beneficiary of the investment, as the Company does not have power to direct the activities of the entity that most significantly affect its performance. As such, the interest in the VIE is recorded using the equity method of accounting in the accompanying consolidated financial statements. Under the equity method, the investment in the unconsolidated entity is stated at cost and adjusted for the Company’s share of net earnings or losses and reduced by distributions. Equity in earnings of real estate ventures is generally recognized based on the allocation of cash distributions upon liquidation of the investment at book value in accordance with the operating agreements. The Company’s maximum exposure to losses associated with its unconsolidated investment is primarily limited to its carrying value in the investment. As of December 31, 2017 , the balance of the investment is shown below: Digital Realty Joint Venture Balance as of December 31, 2016 $ 46,313 Other comprehensive income 465 Net loss (2,065 ) Distributions (7,599 ) Balance as of December 31, 2017 $ 37,114

Debt

Debt	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt	Debt As of September 30, 2018 and December 31, 2017 , the Company's debt and related deferred financing costs consisted of the following: September 30, 2018 December 31, 2017 Contractual Interest Rate (1) Payment Type Loan Maturity Effective Interest Rate (2) BofA/KeyBank Loan $ 250,000 $ — 4.32% Interest Only May 2028 4.36% AIG Loan 126,970 126,970 4.15% Interest Only (3) November 2025 4.22% Total Mortgage Debt 376,970 126,970 Term Loan 113,000 — LIBOR + 1.25% (4) Interest Only June 2023 3.58% Revolving Credit Facility 85 357,758 LIBOR + 1.30% (4)(5) Interest Only June 2023 (6) 3.65% Total Debt 490,055 484,728 Unamortized deferred financing costs (8,482 ) (2,880 ) Total Debt, net $ 481,573 $ 481,848 (1) Including the effect of one interest rate swap agreement with a total notional amount of $100.0 million , the weighted average interest rate as of September 30, 2018 was approximately 3.81% for the Company's fixed-rate and variable-rate debt combined. (2) Includes the effect of amortization of deferred financing costs. (3) The AIG Loan (as defined below) requires monthly payments of interest only, at a fixed rate, for the first five years and fixed monthly payments of principal and interest thereafter. (4) The LIBOR as of September 30, 2018 was 2.11% . (5) As discussed below, the Company entered into an amended and restated credit agreement in June 2018. The contractual interest rate on the original revolving credit facility was LIBOR + 1.50% as of March 31, 2018. (6) The Revolving Credit Facility (as defined below) has an initial term of four years, maturing on June 28, 2022, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below. (7) Amended and Restated Credit Agreement On June 28, 2018, the Company, through the Operating Partnership, entered into an amended and restated credit agreement (the "Amended and Restated Credit Agreement") related to a revolving credit facility and a term loan (collectively, the "Unsecured Credit Facility") with a syndicate of lenders, under which KeyBank, National Association ("KeyBank") serves as administrative agent, and various notes related thereto. In addition, the Company entered into a guaranty agreement. Pursuant to the Amended and Restated Credit Agreement, the Company was provided with a revolving credit facility (the "Revolving Credit Facility") in an initial commitment amount of up to $550 million and a term loan (the "Term Loan") in an initial commitment amount of up to $200 million , which commitments may be increased under certain circumstances up to a maximum total commitment of $1.25 billion . Any increase in the total commitment will be allocated to the Revolving Credit Facility and/or the Term Loan in such amounts as the Operating Partnership and KeyBank may determine. The Revolving Credit Facility may be prepaid and terminated, in whole or in part, at any time without fees or penalty. The Revolving Credit Facility has an initial term of four years , maturing on June 28, 2022. The Revolving Credit Facility may be extended for a one -year period if certain conditions are met and the Operating Partnership pays an extension fee. Payments under the Revolving Credit Facility are interest only and are due on the first day of each quarter. Amounts borrowed under the Revolving Credit Facility may be repaid and reborrowed, subject to the terms of the Amended and Restated Credit Agreement. The Term Loan has an initial term of five years , maturing on June 28, 2023. Payments under the Term Loan are interest only and are due on the first day of each quarter. Amounts borrowed under the Term Loan may not be repaid and reborrowed. The Unsecured Credit Facility has an interest rate calculated based on LIBOR plus the applicable LIBOR margin, as provided in the Amended and Restated Credit Agreement, or the Base Rate plus the applicable base rate margin, as provided in the agreement. The applicable LIBOR margin and base rate margin are dependent on the consolidated leverage ratio of the Operating Partnership, the Company, and the Company's subsidiaries, as disclosed in the periodic compliance certificate provided to the administrative agent each quarter. If the Operating Partnership obtains an investment grade rating of its senior unsecured long term debt from Standard & Poor's Rating Services or Moody's Investors Service, Inc., the applicable LIBOR margin and base rate margin will be dependent on such rating. The Amended and Restated Credit Agreement relating to the Revolving Credit Facility provides that the Operating Partnership must maintain a pool of real properties (each a "Pool Property" and collectively the "Pool Properties") that meet certain requirements contained in the Amended and Restated Credit Agreement. The agreement sets forth certain covenants relating to the Pool Properties, including, without limitation, the following: • there must be no less than 15 Pool Properties; • no greater than 15% of the aggregate pool value may be contributed by a single Pool Property or tenant; • no greater than 15% of the aggregate pool value may be contributed by Pool Properties subject to ground leases; • no greater than 20% of the aggregate pool value may be contributed by Pool Properties which are under development; • the minimum aggregate leasing percentage of all Pool Properties must be no less than 90% ; and • other limitations as determined by KeyBank upon further due diligence of the Pool Properties. Borrowing availability under the Amended and Restated Credit Agreement is limited to the lesser of (i) an asset pool leverage ratio of no greater than 60% , or (ii) an asset pool debt service coverage ratio of no less than 1.35 :1.00. As of September 30, 2018 , the remaining capacity pursuant to the Unsecured Credit Facility was $214.7 million . Bank of America and KeyBank Loan On April 27, 2018, the Company, through four SPEs that own the respective four properties noted below and are owned by the Company's Operating Partnership, entered into a loan agreement (the "Loan Agreement”) with Bank of America, N.A. and KeyBank (together with their successors and assigns, collectively, the "Lender") in which the Company borrowed $250.0 million (the "BofA/KeyBank Loan"). The Company utilized approximately $249.8 million of the proceeds provided by the BofA/KeyBank Loan to pay down a portion of the Company's Revolving Credit Facility. In connection with this pay down of the Company's Revolving Credit Facility, KeyBank released four of the special purpose entities owned by the Company's Operating Partnership from their obligations as guarantors under the Revolving Credit Facility. The BofA/KeyBank Loan is secured by cross-collateralized and cross-defaulted first mortgage liens on the properties with the following tenants: 3M Company, Amazon.com.dedc LLC, Southern Company Services, Inc. and IGT (each, a "Secured Property"). In connection with this transaction, the Company entered into a nonrecourse carve-out guaranty agreement. In addition to their first mortgage lien, the Lender also has a security interest in all other property relating to the ownership, use, maintenance or operation of the improvements on each Secured Property and all rents, profits and revenues from each Secured Property. The BofA/KeyBank Loan has a term of 10 years , maturing on May 1, 2028. The BofA/KeyBank Loan bears interest at an annual rate of 4.32% . Commencing on June 1, 2020, the BofA/KeyBank Loan may be prepaid but only if such prepayment is made in full (with certain exceptions), subject to certain conditions set forth in the Loan Agreement, including 30 days ' prior notice to the Lender and payment of a prepayment premium in addition to all unpaid principal and accrued interest to the date of such prepayment. Commencing on November 1, 2027, the BofA/KeyBank Loan may be prepaid in whole or in part, subject to satisfaction of certain conditions, including 30 days ' prior notice to the Lender, without payment of any prepayment premium. AIG Loan On October 22, 2015, six SPEs that are wholly-owned by the Operating Partnership entered into promissory notes with The Variable Annuity Life Insurance Company, American General Life Insurance Company, and the United States Life Insurance Company (collectively, the "Lenders"), pursuant to which the Lenders provided such SPEs with a loan in the aggregate amount of approximately $127.0 million (the "AIG Loan"). The AIG Loan has a term of 10 years , maturing on November 1, 2025. The AIG Loan bears interest at a rate of 4.15% . The AIG Loan requires monthly payments of interest only for the first five years and fixed monthly payments of principal and interest thereafter. The AIG Loan is secured by cross-collateralized and cross-defaulted first lien deeds of trust and second lien deeds of trust on certain properties. Commencing October 31, 2017, each of the individual promissory notes comprising the AIG Loan may be prepaid but only if such prepayment is made in full, subject to 30 days ' prior notice to the holder and payment of a prepayment premium in addition to all unpaid principal and accrued interest to the date of such prepayment. Debt Covenant Compliance Pursuant to the terms of the Unsecured Credit Facility, BofA/KeyBank Loan and AIG Loan, the Company is subject to certain loan compliance covenants. The Company was in compliance with all applicable covenants as of September 30, 2018 .	Debt As of December 31, 2017 and 2016 , the Company’s debt and related deferred financing costs consisted of the following: December 31, 2017 December 31, 2016 Contractual Interest Rate (1) Payment Type Loan Maturity Effective Interest Rate (4) Revolving Credit Facility $ 357,758 $ 333,458 2.87% Interest Only December 2019 (2) 3.32% AIG Loan 126,970 126,970 4.15% Interest Only (3) November 2025 4.22% Total Debt 484,728 460,428 Unamortized deferred financing costs (2,880 ) (3,956 ) Total Debt, net $ 481,848 $ 456,472 (1) The 2.87% contractual interest rate is based on a 360 -day year, pursuant to the Revolving Credit Facility. The 2.92% weighted-average interest rate is based on a 365 -day year. As discussed below, the interest rate on the Revolving Credit Facility (as defined below) is a one-month LIBO Rate + 1.50% . As of December 31, 2017 , the LIBO Rate was 1.57% . Including the effect of interest rate swap agreements with a total notional amount of $200.0 million , the weighted average interest rate as of December 31, 2017 was approximately 3.13% for the Company’s fixed-rate and variable-rate debt combined. (2) The Revolving Credit Facility has an initial term of four years, maturing on December 12, 2018, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below. (3) The AIG Loan (as defined below) requires monthly payments of interest only, at a fixed rate, for the first five years and fixed monthly payments of principal and interest thereafter. (4) Reflects the effective interest rate at December 31, 2017 and includes the effect of amortization of deferred financing costs. Revolving Credit Facility On December 12, 2014, the Company, through the Operating Partnership, entered into a revolving credit agreement, as amended by the first amendment to the revolving credit agreement dated as of May 27, 2015, and as further amended by the increase agreements to the revolving credit agreement dated as of August 11, 2015 and November 22, 2016, and various notes related thereto, related to a loan with a syndicate of lenders, under which KeyBank, National Association (“KeyBank”) serves as administrative agent; Bank of America, N.A., SunTrust Bank, Capital One, National Association (“Capital One”), and Wells Fargo Bank, National Association, serve as co-syndication agents; and KeyBanc Capital Markets, Merrill Lynch, Pierce, Fenner and Smith Incorporated, SunTrust, Capital One, and Wells Fargo Securities, LLC serve as joint lead arrangers and joint bookrunners. In addition, the Company entered into guaranty agreements. Pursuant to the credit agreement, the Company was provided with a revolving credit facility (as amended, the “Revolving Credit Facility”) in an initial commitment amount of $250.0 million , which commitment may be increased under certain circumstances up to a maximum total commitment of $1.25 billion . On August 11, 2015, the Company exercised its right under the credit agreement to increase the total commitments from $250.0 million to $410.0 million , and on November 22, 2016, the Company exercised its right under the credit agreement to increase the total commitments from $410.0 million to $550.0 million . The Revolving Credit Facility has an initial term of four years , maturing on December 12, 2018. The Revolving Credit Facility may be extended for a one -year period if certain conditions are met and the Company pays an extension fee. Payments under the Revolving Credit Facility are interest only and are due on the first day of each quarter. The Revolving Credit Facility has an interest rate calculated based on LIBOR plus the applicable LIBOR margin, as provided in the credit agreement, or the Base Rate plus the applicable base rate margin, as provided in the credit agreement. The applicable LIBOR margin and base rate margin are dependent on the consolidated leverage ratio of the Company’s Operating Partnership, the Company, and the Company’s subsidiaries, as disclosed in the periodic compliance certificate provided to the administrative agent each quarter. The Revolving Credit Facility was initially secured by a pledge of 100% of the ownership interests in each SPE which owns a pool property. On November 1, 2016, all pledged membership interests were released from the lien of the pledge agreements and subsequently terminated. Adjustments to the applicable LIBOR margin and base rate margin upon the release of the security for the Revolving Credit Facility were effective as of January 1, 2017. The Revolving Credit Facility may be prepaid and terminated, in whole or in part, at any time without fees or penalty. As of December 31, 2017 , the Company was in compliance with all applicable covenants. As of December 31, 2017 , the remaining capacity pursuant to the Revolving Credit Facility was $143.1 million . AIG Loan On October 22, 2015, six SPEs that are wholly-owned by the Operating Partnership entered into promissory notes with The Variable Annuity Life Insurance Company, American General Life Insurance Company, and the United States Life Insurance Company (collectively, the “Lenders”), pursuant to which the Lenders provided such SPEs with a loan in the aggregate amount of approximately $127.0 million (the “AIG Loan”). The AIG Loan has a term of 10 years , maturing on November 1, 2025. The AIG Loan bears interest at a rate of 4.15% . The AIG Loan requires monthly payments of interest only for the first five years and fixed monthly payments of principal and interest thereafter. The AIG Loan is secured by cross-collateralized and cross-defaulted first lien deeds of trust and second lien deeds of trust on certain properties. Commencing October 31, 2017, each of the individual promissory notes comprising the AIG Loan may be prepaid but only if such prepayment is made in full, subject to 30 days’ prior notice to the holder and payment of a prepayment premium in addition to all unpaid principal and accrued interest to the date of such prepayment. As of December 31, 2017 , there was approximately $127.0 million outstanding pursuant to the AIG Loan. Debt Covenant Compliance Pursuant to the terms of the Revolving Credit Facility and AIG Loan, the Company is subject to certain loan compliance covenants. The Company was in compliance with all applicable covenants as of December 31, 2017 . The following summarizes the future principal repayments of all loans as of December 31, 2017 per the loan terms discussed above: December 31, 2017 2018 $ — 2019 357,758 2020 — 2021 2,178 2022 2,271 Thereafter 122,521 Total principal 484,728 Unamortized deferred loan costs (2,880 ) Total $ 481,848
Griffin Capital Essential Asset REIT, Inc. [Member]
Debt Instrument [Line Items]
Debt	Debt As of September 30, 2018 and December 31, 2017 , the Company’s debt consisted of the following: September 30, 2018 December 31, 2017 Contractual Interest Rate (1) Loan Maturity Effective Interest Rate (2) TW Telecom loan (3) $ — $ 19,169 — — —% HealthSpring loan 21,340 21,694 4.18% April 2023 4.60% Midland loan 102,753 104,197 3.94% April 2023 4.12% Emporia Partners loan 2,662 2,978 5.88% September 2023 5.96% Samsonite loan 22,309 22,961 6.08% September 2023 5.16% Highway 94 loan 16,714 17,352 3.75% August 2024 4.65% Bank of America loan 375,000 375,000 3.77% October 2027 3.91% AIG loan 107,998 109,275 4.96% February 2029 5.07% Total Mortgage Debt 648,776 672,626 Term Loan 715,000 715,000 LIBOR+1.40% (4) July 2020 3.89% Revolver Loan — 10,153 LIBOR +1.45% (4) July 2020 (4) 3.77% Total Debt 1,363,776 1,397,779 Unamortized Deferred Financing Costs and Discounts, net (9,426 ) (11,695 ) Total Debt, net $ 1,354,350 $ 1,386,084 (1) Including the effect of one interest rate swap agreement with a total notional amount of $425.0 million , the weighted average interest rate as of September 30, 2018 was 3.70% for the Company’s fixed-rate and variable-rate debt combined and 3.75% for the Company’s fixed-rate debt only. (2) Reflects the effective interest rate as of September 30, 2018 and includes the effect of amortization of discounts/premiums and deferred financing costs. (3) In March 2018, the Company, through the Operating Partnership, paid off the remaining balance of the TW Telecom loan. (4) The LIBO rate as of September 30, 2018 was 2.11% .The Revolver Loan has an initial term of four years, maturing on July 20, 2019, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below. Unsecured Credit Facility On July 20, 2015, the Company, through the Operating Partnership, entered into an amended and restated credit agreement, as amended by that certain first amendment to amended and restated credit agreement dated as of February 12, 2016 (as amended, the "Unsecured Credit Agreement") with a syndicate of lenders, co-led by KeyBank National Association ("KeyBank"), Bank of America, N.A. ("Bank of America"), Fifth Third Bank ("Fifth Third"), and BMO Harris Bank, N.A. ("BMO Harris"), under which KeyBank serves as administrative agent and Bank of America, Fifth Third, and BMO Harris serve as co-syndication agents, and KeyBanc Capital Markets, Merrill Lynch, Pierce, Fenner & Smith Incorporated ("Merrill Lynch"), Fifth Third, and BMO Capital Markets serve as joint bookrunners and joint lead arrangers. Pursuant to the Unsecured Credit Agreement, the Company was provided with a $1.14 billion senior unsecured credit facility (the "Unsecured Credit Facility"), consisting of a $500.0 million senior unsecured revolver (the "Revolver Loan") and a $640.0 million senior unsecured term loan (the "Term Loan"). The Unsecured Credit Facility may be increased up to $860.0 million , in minimum increments of $50.0 million , for a maximum of $2.0 billion by increasing either the Revolver Loan, the Term Loan, or both. The Revolver Loan has an initial term of four years, maturing on July 20, 2019, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. The Term Loan has a term of five years, maturing on July 20, 2020. On March 29, 2016, the Company exercised its right to increase the total commitments, pursuant to the Unsecured Credit Agreement. As a result, the total commitments on the Term Loan increased from $640.0 million to $715.0 million . Bank of America Loan On September 29, 2017, the Company, through ten SPEs wholly owned by the Operating Partnership, entered into a loan agreement with Bank of America, N.A. (together with its successors and assigns, the "Lender") in which the Company borrowed $375.0 million (the “Bank of America Loan”). The Bank of America Loan is secured by cross-collateralized and cross-defaulted first mortgage liens on ten properties. The Bank of America Loan has a term of 10 years , maturing on October 1, 2027. The Bank of America Loan bears interest at a rate of 3.77% and requires monthly payments of interest only. Debt Covenant Compliance Pursuant to the terms of the Company's mortgage loans, Unsecured Credit Facility, and Bank of America Loan the Operating Partnership, in consolidation with the Company, is subject to certain loan compliance covenants. The Company was in compliance with all of its debt covenants as of September 30, 2018 .	Debt As of December 31, 2017 and December 31, 2016, the Company’s debt consisted of the following: December 31, 2017 December 31, 2016 Contractual Interest Rate (1) Loan Maturity Effective Interest Rate (2) Plainfield loan $ — $ 18,932 — — — Emporia Partners loan 2,978 3,377 5.88% September 2023 5.96% Ace Hardware loan — 22,922 — — — Highway 94 loan 17,352 18,175 3.75% August 2024 4.63% Samsonite loan 22,961 23,786 6.08% September 2023 5.22% HealthSpring loan 21,694 22,149 4.18% April 2023 4.59% Midland loan 104,197 105,600 3.94% April 2023 4.08% AIG loan 109,275 110,640 4.96% February 2029 5.07% TW Telecom loan 19,169 20,353 LIBO Rate +2.45% (3) August 2019 4.04% Bank of America loan 375,000 — 3.77% August 2027 3.90% Total Mortgage Debt 672,626 345,934 Term Loan 715,000 715,000 LIBO Rate +1.40% (3) July 2020 3.19% Revolver Loan 10,153 397,409 LIBO Rate +1.45% (3) July 2020 (4) 3.79% Total Debt 1,397,779 1,458,343 Unamortized Deferred Financing Costs and Discounts, net (11,695 ) (10,808 ) Total Debt, net $ 1,386,084 $ 1,447,535 (1) Including the effect of interest rate swap agreements with a total notional amount of $725.0 million , the weighted average interest rate as of December 31, 2017 was 3.53% for the Company’s fixed-rate and variable-rate debt combined and 3.54% for the Company’s fixed-rate debt only. (2) Reflects the effective interest rate as of December 31, 2017 and includes the effect of amortization of discounts/premiums and deferred financing costs. (3) The LIBO Rate as of December 31, 2017 was 1.56% . (4) The Revolver Loan has an initial term of four years , maturing on July 20, 2019, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below. Unsecured Credit Facility On July 20, 2015, the Company, through the Operating Partnership, entered into a credit agreement (the “Unsecured Credit Agreement “) with a syndicate of lenders, co-led by KeyBank National Association (“KeyBank”), Bank of America, N.A. (“Bank of America”), Fifth Third Bank (“Fifth Third”), and BMO Harris Bank, N.A. (“BMO Harris”), under which KeyBank serves as administrative agent and Bank of America, Fifth Third, and BMO Harris serve as co-syndication agents, and KeyBanc Capital Markets, Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”), Fifth Third, and BMO Capital Markets serve as joint bookrunners and joint lead arrangers. Pursuant to the Unsecured Credit Agreement, the Company was provided with a $1.14 billion senior unsecured credit facility (the “Unsecured Credit Facility”), consisting of a $500.0 million senior unsecured revolver (the “Revolver Loan”) and a $640.0 million senior unsecured term loan (the “Term Loan”). The Unsecured Credit Facility may be increased up to $860.0 million , in minimum increments of $50.0 million , for a maximum of $2.0 billion by increasing either the Revolver Loan, the Term Loan, or both. The Revolver Loan has an initial term of four years, maturing on July 20, 2019, and may be extended for a one-year period if certain conditions are met and upon payment of an extension fee. The Term Loan has a term of five years , maturing on July 20, 2020. On March 29, 2016, the Company exercised its right to increase the total commitments, pursuant to the Unsecured Credit Agreement. As a result, the total commitments on the Term Loan increased from $640.0 million to $715.0 million . In March 2017, the Company, through the Operating Partnership, drew an additional $23.0 million to pay off the remaining balance of the Ace Hardware loan. In September 2017, the Company, through the Operating Partnership, drew an additional $21.0 million to pay down the remaining $18.7 million Plainfield loan balance and the remaining proceeds were used to fund operations. For the year ended December 31, 2017, the Company paid down approximately $344.1 million of the Unsecured Credit Facility, as a result of the Bank of America financing, as further described below. Bank of America Loan On September 29, 2017, the Company, through ten SPEs wholly owned by the Operating Partnership, entered into a loan agreement with Bank of America, N.A. (together with its successors and assigns, the “Lender”) in which the Company borrowed $375.0 million (the “Bank of America Loan”). The Company utilized approximately $344.1 million of the funds provided by the Bank of America Loan to pay down a portion of the Company’s Unsecured Credit Facility. In connection with this pay down of the Unsecured Credit Facility, KeyBank released eight SPEs owned by the Operating Partnership from their obligations as guarantors under the Unsecured Credit Facility. The Bank of America Loan is secured by cross-collateralized and cross-defaulted first mortgage liens on the properties (or in the case of one property, on the SPE’s leasehold interest in the property) with the following tenants: ACE Hardware Corporation; Christus Health; Comcast of Washington; Connecticut General; General Electric Company; NEC Corporation of America; Restoration Hardware, Inc.; State Farm Mutual Automobile Insurance Co.; T-Mobile West LLC; and WellsFargo Bank, National Association (each, a “Secured Property”). In addition, the Company entered into a nonrecourse carve-out guaranty agreement. In addition to their first mortgage lien, the Lender also has a security interest in all other property relating to the ownership, use, maintenance or operation of the improvements on each Secured Property and all rents, profits and revenues from each Secured Property. The Bank of America Loan has a term of 10 years , maturing on October 1, 2027. The Bank of America Loan bears interest at a rate of 3.77% and requires monthly payments of interest only. Commencing September 1, 2019, the Bank of America Loan may be prepaid but only if such prepayment is made in full (with certain exceptions), subject to certain conditions set forth in the loan agreement, including 30 days’ prior notice to the Lender and payment of a prepayment premium in addition to all unpaid principal and accrued interest to the date of such prepayment. Commencing on April 1, 2027, the Bank of America Loan may be prepaid in whole or in part, subject to satisfaction of certain conditions, including 30 days’ prior notice to the Lender, without payment of any prepayment premium. The Company paid processing fees, as well as certain other closing costs, including legal fees, of approximately $3.0 million in connection with the Bank of America Loan. Debt Covenant Compliance Pursuant to the terms of the Company’s mortgage loans, Unsecured Credit Facility and Bank of America Loan, the Operating Partnership, in consolidation with the Company, is subject to certain loan compliance covenants. The Company was in compliance with all of its debt covenants as of December 31, 2017. The following summarizes the future principal repayments of all loans as of December 31, 2017 per the loan terms discussed above: December 31, 2017 2018 $ 7,132 2019 24,879 2020 732,034 2021 7,211 2022 7,556 Thereafter 618,967 Total principal 1,397,779 Unamortized debt premium/(discount) (281 ) Unamortized deferred loan costs (11,414 ) Total $ 1,386,084

Interest Rate Contracts

Interest Rate Contracts	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Interest Rate Contracts	Interest Rate Contracts Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both business operations and economic conditions. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of debt funding and the use of derivative financial instruments. Specifically, the Company entered into derivative financial instruments to manage exposures that arise from business activities that result in the payment of future known and uncertain cash amounts, the value of which are determined by expected cash payments principally related to borrowings and interest rates. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The Company does not use derivatives for trading or speculative purposes. Derivative Instruments The Company entered into an interest rate swap agreement to hedge the variable cash flows associated with the LIBO Rate-based variable-rate debt on the Company's Revolving Credit Facility. The interest rate swap is effective for the period from April 1, 2016 to December 12, 2018 with a notional amount of $100.0 million . Effective as of November 1, 2017, Griffin Capital Essential Asset Operating Partnership, L.P., an affiliated party of the Sponsor, novated one of its $100.0 million swaps to the Operating Partnership, as a result of the repayment of debt. The terms of the cash flow swap are listed in the table below. On April 30, 2018, the Company settled the $100.0 million cash flow hedge contract purchased from Griffin Capital Essential Asset Operating Partnership, L.P., which resulted in the Company receiving a net settlement of approximately $0.1 million . The change in the fair value of derivatives designated and qualifying as cash flow hedges is initially recorded in AOCI and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. Amounts reported in accumulated other comprehensive income ("AOCI") related to derivatives will be reclassified to interest expense as interest payments are made on the Company's variable-rate debt. The following table sets forth a summary of the interest rate swaps at September 30, 2018 and December 31, 2017 : Fair Value (1) Derivative Instruments Effective Date Maturity Date/ Termination Interest Strike Rate September 30, 2018 December 31, 2017 Assets Interest Rate Swap 4/1/2016 12/12/2018 0.74% $ 310 $ 967 Interest Rate Swap (terminated on April 30, 2018) 11/1/2017 4/30/2018 1.50% — 65 $ 310 $ 1,032 (1) The Company records all derivative instruments on a gross basis on the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of September 30, 2018 , the Company's derivative was in an asset position, and as such, the fair value is included in the line item "Other Assets, net" on the consolidated balance sheet. The following table sets forth the impact of the interest rate swaps on the consolidated financial statements for the nine months ended September 30, 2018 and 2017 : Nine Months Ended September 30, 2018 2017 Interest Rate Swaps in Cash Flow Hedging Relationship: Amount of (gain) recognized in AOCI on derivatives $ (281 ) $ (190 ) Amount of gain reclassified from AOCI into earnings under “Interest expense” $ 922 $ 207 Total interest expense presented in the consolidated statement of operations in which the effects of cash flow hedges are recorded $ 14,775 $ 11,445 During the twelve months subsequent to September 30, 2018 , the Company estimates that an additional $0.3 million of income will be recognized from AOCI into earnings. The Company's agreements with the derivative counterparties contain a provision where if the Company defaults on any of the Company's indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender within a specified time period, then the Company could also be declared in default on its derivative obligations. As of September 30, 2018 , the fair value of the interest rate swap was in an asset position excluding any adjustment for nonperformance risk related to the Company's derivative counterparty agreement, which was approximately $0.3 million . As of September 30, 2018 , the Company had not posted any collateral related to the Company's derivative counterparty agreements.	Interest Rate Contracts Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both business operations and economic conditions. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of debt funding and the use of derivative financial instruments. Specifically, the Company entered into derivative financial instruments to manage exposures that arise from business activities that result in the payment of future known and uncertain cash amounts, the value of which are determined by expected cash payments principally related to borrowings and interest rates. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The Company does not use derivatives for trading or speculative purposes. Derivative Instruments On February 25, 2016, the Company entered into an interest rate swap agreement to hedge the variable cash flows associated with the LIBO Rate-based variable-rate debt on the Company’s Revolving Credit Facility. The interest rate swap is effective for the period from April 1, 2016 to December 12, 2018 with a notional amount of $100.0 million . Effective as of November 1, 2017, Griffin Capital Essential Asset Operating Partnership, L.P, an affiliated party of the Company, novated one of its $100 million swaps to the Operating Partnership, as a result of the repayment of debt. The terms of the cash flow swap are listed in the table below. The effective portion of the change in the fair value of derivatives designated and qualifying as cash flow hedges is initially recorded in AOCI and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. Amounts reported in AOCI related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt. The following table sets forth a summary of the interest rate swaps at December 31, 2017 and December 31, 2016 : Fair Value (1) Current Effective Notional Amount (2) Derivative Instrument Effective Date Maturity Date Interest Strike Rate December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Assets Interest Rate Swap 4/1/2016 12/12/2018 0.74% $ 967 $ 996 $ 100,000 $ 100,000 Interest Rate Swap (3) 11/1/2017 7/1/2018 1.50% 65 — 100,000 — Total $ 1,032 $ 996 $ 200,000 $ 100,000 (1) The Company records all derivative instruments on a gross basis on the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of December 31, 2017 , the Company’s derivatives were in asset positions, and as such, the fair value is included in the line item “Other Assets, net” on the consolidated balance sheet. (2) Represents the notional amount of swap that was effective as of the balance sheet date of December 31, 2017 and December 31, 2016 . (3) Effective as of November 1, 2017, Griffin Capital Essential Asset Operating Partnership, L.P, an affiliated party novated a $100 million interest rate swap agreement with an expiration date of June 1, 2018 to the Company’s Operating Partnership. The Company paid approximately nine thousand dollars, which approximated fair value. The following table sets forth the impact of the interest rate swaps on the consolidated financial statements for the periods presented: Year Ended December 31, 2017 2016 Interest Rate Swaps in Cash Flow Hedging Relationship: Amount of loss recognized in AOCI on derivative (effective portion) $ 428 $ 662 Amount of (gain) loss reclassified from AOCI into earnings under “Interest expense” (effective portion) $ (319 ) $ 179 Amount of (loss) gain recognized in earnings under “Interest expense” (ineffective portion and amount excluded from effectiveness testing) $ (80 ) $ 155 During the twelve months subsequent to December 31, 2017 , the Company estimates that an additional $1.0 million will be recognized from AOCI into earnings. The Company’s agreement with the derivative counterparty contains a provision where if the Company defaults on any of the Company’s indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender within a specified time period, then the Company could also be declared in default on its derivative obligation. As of December 31, 2017 , the fair value of interest rate swaps were in asset positions excluding any adjustment for nonperformance risk related to the Company’s derivative counterparty agreement, which was approximately $1.0 million . As of December 31, 2017 , the Company had not posted any collateral related to the Company’s derivative counterparty agreement.
Griffin Capital Essential Asset REIT, Inc. [Member]
Derivative [Line Items]
Interest Rate Contracts	6. Interest Rate Contracts Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both business operations and economic conditions. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of debt funding and the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the payment of future known and uncertain cash amounts, the value of which are determined by expected cash payments principally related to borrowings and interest rates. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The Company does not use derivatives for trading or speculative purposes. Derivative Instruments On August 31, 2018, the Company executed four interest rate swap agreements to hedge future variable cash flows associated with London Interbank Offered Rate ("LIBOR"). The forward-starting interest rate swaps with a total notional amount of $425 million become effective on July 1, 2020 and have a term of five years . The Company has entered into interest rate swap agreements to hedge the variable cash flows associated with certain existing or forecasted LIBOR based variable-rate debt, including the Company's Unsecured Credit Facility. The change in the fair value of derivatives designated and qualifying as cash flow hedges is initially recorded in AOCI and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. Amounts reported in accumulated other comprehensive income ("AOCI") related to derivatives will be reclassified to interest expense as interest payments are made on the Company's variable-rate debt. The following table sets forth a summary of the interest rate swaps at September 30, 2018 and December 31, 2017 : Fair Value (1) Derivative Instrument Notional Amounts Effective Date Maturity Date Interest Strike Rate September 30, 2018 December 31, 2017 Assets Interest Rate Swap $ 425,000 7/9/2015 7/1/2020 1.69% $ 8,016 $ 3,255 Interest Rate Swap 300,000 1/1/2016 7/1/2018 1.32% — 458 Interest Rate Swap 125,000 7/1/2020 7/1/2025 2.82% 903 — Interest Rate Swap 100,000 7/1/2020 7/1/2025 2.82% 697 — Interest Rate Swap 100,000 7/1/2020 7/1/2025 2.83% 677 — Interest Rate Swap 100,000 7/1/2020 7/1/2025 2.84% 599 — Total $ 1,150,000 $ 10,892 $ 3,713 (1) The Company records all derivative instruments on a gross basis in the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of September 30, 2018 , derivatives in an asset position are included in the line item "Other assets" in the consolidated balance sheets at fair value. The following table sets forth the impact of the interest rate swaps on the consolidated statements of operations for the periods presented: Nine Months Ended September 30, 2018 2017 Interest Rate Swap in Cash Flow Hedging Relationship: Amount of (gain) loss recognized in AOCI on derivatives $ (8,458 ) $ (142 ) Amount of gain (loss) reclassified from AOCI into earnings under “Interest expense” $ 1,182 $ (3,330 ) Total interest expense presented in the consolidated statement of operations in which the effects of cash flow hedges are recorded $ 41,251 $ 37,232 During the 12 months subsequent to September 30, 2018 , the Company estimates that an additional $3.9 million of income will be recognized from AOCI into earnings. Certain agreements with the derivative counterparties contain a provision where if the Company defaults on any of the Company's indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender within a specified time period, then the Company could also be declared in default on its derivative obligations. As of September 30, 2018 and December 31, 2017 , the fair value of interest rate swaps in a net asset position, which excludes any adjustment for nonperformance risk related to these agreements, was approximately $10.9 million and $3.7 million , respectively. As of September 30, 2018 and December 31, 2017 , the Company had not posted any collateral related to these agreements.	Interest Rate Contracts Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both business operations and economic conditions. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of debt funding and the use of derivative financial instruments. Specifically, the Company entered into derivative financial instruments to manage exposures that arise from business activities that result in the payment of future known and uncertain cash amounts, the value of which are determined by expected cash payments principally related to borrowings and interest rates. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The Company does not use derivatives for trading or speculative purposes. Derivative Instruments The Company has entered into three interest rate swap agreements to hedge the variable cash flows associated with certain existing or forecasted LIBO Rate-based variable-rate debt, including the Company’s Unsecured Credit Facility. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income (“AOCI”) and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The Company’s derivatives were used to hedge the variable cash flows associated with existing variable-rate debt and forecasted issuances of debt. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. The following table sets forth a summary of the interest rate swaps at December 31, 2017 and December 31, 2016 : Fair Value (1) Current Notional Amount (2) December 31, Derivative Instrument Effective Date Maturity Date Interest Strike Rate 2017 2016 2017 2016 Assets/(Liabilities): Interest Rate Swap 7/9/2015 7/1/2020 1.69% $ 3,255 $ (1,630 ) $ 425 $ 425 Interest Rate Swap 1/1/2016 7/1/2018 1.32% 458 (907 ) 300 300 Interest Rate Swap (3) 7/1/2016 7/1/2018 1.50% — (564 ) — 100 Total $ 3,713 $ (3,101 ) $ 725 $ 825 (1) The Company records all derivative instruments on a gross basis in the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of December 31, 2017 , derivatives in a asset/liability position are included in the line item “Other assets/Accrued expenses and other liabilities,” respectively, in the consolidated balance sheets at fair value. (2) Represents the notional amount of swaps that are effective as of the balance sheet date of December 31, 2017 and 2016 . (3) Effective as of November 1, 2017, the Operating Partnership novated the $100 million interest rate swap agreement to an affiliated party, Griffin Capital Essential Asset Operating Partnership II, L.P., for approximately nine-thousand dollars. At the date of novation, the Company accelerated the reclassification of amounts in other comprehensive income to earnings as a result of the hedged forecasted transactions becoming probable not to occur. The novation involved cash consideration that reflected the termination value of the trade at the time of novation. The following table sets forth the impact of the interest rate swap on the consolidated statements of operations for the periods presented: Year Ended December 31, 2017 2016 Interest Rate Swap in Cash Flow Hedging Relationship: Amount of gain (loss) recognized in AOCI on derivatives (effective portion) $ 3,035 $ (6,253 ) Amount of gain (loss) reclassified from AOCI into earnings under “Interest expense” (effective portion) $ 3,856 $ (8,286 ) Amount of gain (loss) recognized in earnings under “Interest expense” (ineffective portion and amount excluded from effectiveness testing) $ (19 ) $ (70 ) During the next twelve months, the Company estimates that an additional $0.8 million will be recognized from AOCI into earnings. Certain agreements with the derivative counterparties contain a provision where if the Company defaults on any of the Company’s indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender within a specified time period, then the Company could also be declared in default on its derivative obligations. As of December 31, 2017 and December 31, 2016 , the fair value of interest rate swaps in a net asset position/net liabilities, which excludes any adjustment for nonperformance risk related to these agreements, was approximately $3.7 million and $3.1 million , respectively. As of December 31, 2017 and December 31, 2016 , the Company had not posted any collateral related to these agreements.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities (Notes)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Accounts Payable And Accrued Liabilities [Line Items]
Accrued Expenses and Other Liabilities	Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consisted of the following as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 Prepaid rent $ 4,866 $ 4,304 Leasing commission payable 1,900 3,783 Accrued property taxes 3,633 3,490 Interest expense payable 2,661 3,013 Redemptions payable 6,671 2,181 Other liabilities 2,034 3,132 Total $ 21,765 $ 19,903	Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consisted of the following as of December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 Prepaid rent $ 4,304 $ 9,484 Leasing commission payable 3,783 3,783 Accrued property taxes 3,490 2,678 Interest expense payable 3,013 1,716 Other liabilities 5,313 3,866 Total $ 19,903 $ 21,527
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Accrued Expenses and Other Liabilities	Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consisted of the following as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 Prepaid rent $ 14,543 $ 16,138 Real estate taxes payable 25,666 21,087 Interest payable 9,270 7,924 Other liabilities 25,455 18,457 Total $ 74,934 $ 63,606	Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consisted of the following as of December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 Prepaid rent $ 16,312 $ 16,799 Real estate taxes payable 21,317 24,585 Interest payable 7,924 7,606 Interest rate swap liability — 3,101 Other liabilities 18,580 12,914 Total $ 64,133 $ 65,005

Fair Value Measurements

Fair Value Measurements	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements	Fair Value Measurements The Company is required to disclose fair value information about all financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practicable to estimate fair value. The Company measures and discloses the estimated fair value of financial assets and liabilities utilizing a fair value hierarchy that distinguishes between data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consists of three broad levels, as follows: (i) quoted prices in active markets for identical assets or liabilities, (ii) "significant other observable inputs," and (iii) "significant unobservable inputs." "Significant other observable inputs" can include quoted prices for similar assets or liabilities in active markets, as well as inputs that are observable for the asset or liability, such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. "Significant unobservable inputs" are typically based on an entity’s own assumptions, since there is little, if any, related market activity. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. There were no transfers between the levels in the fair value hierarchy during the nine months ended September 30, 2018 and the year ended December 31, 2017 . The following tables set forth the assets that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2018 : Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Interest Rate Swaps at: September 30, 2018 $ 310 $ — $ 310 $ — December 31, 2017 $ 1,032 $ — $ 1,032 $ — Financial instruments as of September 30, 2018 and December 31, 2017 consisted of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, other accrued expenses, and borrowings. With the exception of the mortgage loan in the table below, the amounts of the financial instruments presented in the consolidated financial statements substantially approximate their fair value as of September 30, 2018 and December 31, 2017 . The fair value of the mortgage loan is estimated by discounting the loan’s principal balance over the remaining term of the mortgage using current borrowing rates available to the Company for debt instruments with similar terms and maturities. The Company determined that the mortgage loan valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt, and there were no transfers into and out of fair value measurement levels during the nine months ended September 30, 2018 and for the year ended December 31, 2017 . September 30, 2018 December 31, 2017 Fair Value Carrying Value (1) Fair Value Carrying Value (1) AIG Loan $ 119,338 $ 126,970 $ 122,928 $ 126,970 (1) The carrying value of the AIG Loan does not include deferred financing costs as of September 30, 2018 and December 31, 2017 . See Note 4, Debt , for details.	Fair Value Measurements The Company is required to disclose fair value information about all financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practicable to estimate fair value. The Company measures and discloses the estimated fair value of financial assets and liabilities utilizing a fair value hierarchy that distinguishes between data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consists of three broad levels, as follows: (i) quoted prices in active markets for identical assets or liabilities, (ii) “significant other observable inputs,” and (iii) “significant unobservable inputs.” “Significant other observable inputs” can include quoted prices for similar assets or liabilities in active markets, as well as inputs that are observable for the asset or liability, such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. “Significant unobservable inputs” are typically based on an entity’s own assumptions, since there is little, if any, related market activity. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. There were no transfers between the levels in the fair value hierarchy during the year ended December 31, 2017 . The following tables set forth the assets/(liabilities) that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2017 and 2016 : Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Interest Rate Swaps at: December 31, 2017 $ 1,032 $ — $ 1,032 $ — December 31, 2016 $ 996 $ — $ 996 $ — Financial instruments as of December 31, 2017 consisted of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, other accrued expenses, and borrowings. With the exception of the mortgage loan in the table below, the amounts of the financial instruments presented in the consolidated financial statements substantially approximate their fair value as of December 31, 2017 . The fair value of the mortgage loan is estimated by discounting the loan’s principal balance over the remaining term of the mortgage using current borrowing rates available to the Company for debt instruments with similar terms and maturities. The Company determined that the mortgage loan valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt, and there were no transfers into and out of fair value measurement levels during the years ended December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Fair Value Carrying Value (1) Fair Value Carrying Value (1) AIG Loan $ 122,928 $ 126,970 $ 120,322 $ 126,970 (1) The carrying value of the AIG Loan does not include deferred financing costs as of December 31, 2017 and 2016 . See Note 4, Debt , for details.
Griffin Capital Essential Asset REIT, Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements	Fair Value Measurements The Company is required to disclose fair value information about all financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practicable to estimate fair value. The Company measures and discloses the estimated fair value of financial assets and liabilities utilizing a fair value hierarchy that distinguishes between data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consists of three broad levels, as follows: (i) quoted prices in active markets for identical assets or liabilities, (ii) "significant other observable inputs," and (iii) "significant unobservable inputs." "Significant other observable inputs" can include quoted prices for similar assets or liabilities in active markets, as well as inputs that are observable for the asset or liability, such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. "Significant unobservable inputs" are typically based on an entity’s own assumptions, since there is little, if any, related market activity. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. There were no transfers between the levels in the fair value hierarchy during the nine months ended September 30, 2018 and the year ended December 31, 2017 . The following tables set forth the assets that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2018 and December 31, 2017 : Assets/(Liabilities) Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs September 30, 2018 Interest Rate Swap Asset $ 10,892 $ — $ 10,892 $ — December 31, 2017 Interest Rate Swap Asset $ 3,713 $ — $ 3,713 $ — Financial Instruments Disclosed at Fair Value Financial instruments as of September 30, 2018 and December 31, 2017 consisted of cash and cash equivalents, restricted cash, accounts receivable, accrued expenses and other liabilities, and mortgage payable and other borrowings, as defined in Note 5, Debt . With the exception of the mortgage loans in the table below, the amounts of the financial instruments presented in the consolidated financial statements substantially approximate their fair value as of September 30, 2018 and December 31, 2017 . The fair value of the two mortgage loans in the table below is estimated by discounting each loan’s principal balance over the remaining term of the mortgage using current borrowing rates available to the Company for debt instruments with similar terms and maturities. The Company determined that the mortgage debt valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt. September 30, 2018 December 31, 2017 Fair Value Carrying Value (1) Fair Value Carrying Value (1) Highway 94 loan $ 15,637 $ 16,714 $ 16,484 $ 17,352 BofA loan $ 361,602 $ 375,000 $ 377,289 $ 375,000 (1) The carrying values do not include the debt premium/(discount) or deferred financing costs as of September 30, 2018 and December 31, 2017 . See Note 5, Debt , for details.	Fair Value Measurements The Company is required to disclose fair value information about all financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practicable to estimate fair value. The Company measures and discloses the estimated fair value of financial assets and liabilities utilizing a fair value hierarchy that distinguishes between data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consists of three broad levels, as follows: (i) quoted prices in active markets for identical assets or liabilities, (ii) “significant other observable inputs,” and (iii) “significant unobservable inputs.” “Significant other observable inputs” can include quoted prices for similar assets or liabilities in active markets, as well as inputs that are observable for the asset or liability, such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. “Significant unobservable inputs” are typically based on an entity’s own assumptions, since there is little, if any, related market activity. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. There were no transfers between the levels in the fair value hierarchy during the years ended December 31, 2017 and 2016 . The following tables set forth the assets and liabilities that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2017 and 2016 : Assets/(Liabilities) Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs December 31, 2017 Interest Rate Swap Asset $ 3,713 $ — $ 3,713 $ — December 31, 2016 Interest Rate Swap Liability $ (3,101 ) $ — $ (3,101 ) $ — Financial Instruments Disclosed at Fair Value Financial instruments as of December 31, 2017 and 2016 consisted of cash and cash equivalents, restricted cash, accounts receivable, accrued expenses and other liabilities, and mortgage payable and other borrowings, as defined in Note 5, Debt . With the exception of the mortgage loans in the table below, the amounts of the financial instruments presented in the consolidated financial statements substantially approximate their fair value as of December 31, 2017 and 2016 . The fair value of the three mortgage loans in the table below is estimated by discounting each loan’s principal balance over the remaining term of the mortgage using current borrowing rates available to the Company for debt instruments with similar terms and maturities. The Company determined that the mortgage debt valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt. December 31, 2017 December 31, 2016 Fair Value Carrying Value (1) Fair Value Carrying Value (1) AIG loan $ 113,715 $ 109,275 $ 113,052 $ 110,640 Highway 94 loan 16,484 17,352 17,073 18,175 Samsonite loan 23,851 22,961 24,349 23,786 (1) The carrying values do not include the debt premium/(discount) or deferred financing costs as of December 31, 2017 and 2016 . See Note 5, Debt , for details.

Equity

Equity	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Equity	Equity Status of Offerings On January 20, 2017, the Company closed the primary portion of the IPO; however, the Company continued to offer shares pursuant to the DRP under the IPO registration statement through May 2017. The Company is currently offering shares pursuant to the DRP. The DRP may be terminated at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company's filings with the SEC. On September 20, 2017, the Company commenced the Follow-On Offering of up to $2.2 billion of shares, consisting of up to $2.0 billion of shares in the Company's primary offering and $0.2 billion of shares (including Class A, Class AA and Class AAA shares) pursuant to the DRP. The Company reclassified all Class T and Class I shares sold in the IPO as "Class AA" and "Class AAA" shares, respectively. The Company offered Class T shares, Class S shares, Class D shares and Class I shares in its Follow-On Offering. On August 16, 2018, in connection with a potential strategic alternative the Company’s board of directors is contemplating, the board approved the temporary suspension of the primary portion of the Company's Follow-On Offering, effective August 17, 2018, to allow the special committee of the board to evaluate a potential strategic alternative. The board of directors intends to recommence the Follow-On Offering in the retail marketplace, if appropriate and at the appropriate time. Share Classes Class T shares, Class S shares, Class D shares, Class I shares, Class A shares, Class AA shares and Class AAA shares vote together as a single class, and each share is entitled to one vote on each matter submitted to a vote at a meeting of the Company's stockholders; provided that with respect to any matter that would only have a material adverse effect on the rights of a particular class of common stock, only the holders of such affected class are entitled to vote. The following table summarizes shares issued and gross proceeds received for each share class as of September 30, 2018 and outstanding shares as of September 30, 2018 and December 31, 2017 : Class T Class S Class D Class I Class A Class AA Class AAA Total Gross proceeds from primary portion of offerings $ 2,245 $ 3 $ 182 $ 7,538 $ 240,780 $ 474,858 $ 8,381 $ 733,987 Gross proceeds from DRP $ 16 $ — $ 2 $ 158 $ 25,328 $ 32,369 $ 503 $ 58,376 Shares issued in primary portion of offerings 224,647 264 18,921 786,573 24,199,764 47,562,870 901,225 73,694,264 DRP shares issued 1,650 13 236 16,496 2,669,097 3,412,273 53,014 6,152,779 Stock distribution shares issued — — — — 263,642 300,166 4,677 568,485 Restricted stock issued — — — — — — 36,000 36,000 Total redemptions — — — — (1,351,178 ) (1,434,491 ) (5,593 ) (2,791,262 ) Total shares outstanding as of September 30, 2018 226,297 277 19,157 803,069 25,781,325 49,840,818 989,323 77,660,266 Total shares outstanding as of December 31, 2017 4,148 268 268 267,476 25,995,943 49,942,471 964,709 77,175,283 Organizational and Offering Costs Pursuant to the Advisory Agreement, in no event will the Company be obligated to reimburse the Advisor for organizational and offering costs incurred in connection with the Follow-On Offering totaling in excess of 15% (including selling commissions, dealer manager fees, distribution fees and non-accountable due diligence expense allowance, but excluding acquisition expenses or any fees, if ever applicable) of the gross proceeds raised in the Follow-On Offering (excluding gross proceeds from the DRP). If the organizational and offering costs exceed such limits discussed above, within 60 days after the end of the month in which the Follow-On Offering terminates or is completed, the Advisor is obligated to reimburse the Company for any excess amounts. As long as the Company is subject to the Statement of Policy Regarding Real Estate Investment Trusts published by the North American Securities Administrators Association (“NASAA REIT Guidelines”), such limitation discussed above will also apply to any future public offerings. As of September 30, 2018 , organizational and offering costs relating to the Follow-On Offering were 33.3% (approximately $3.3 million ) of gross offering proceeds ( $10.0 million ), including selling commissions, dealer manager fees and distribution fees. Therefore, if the Follow-On Offering had been terminated on September 30, 2018 , the Company would owe the Advisor $1.5 million and the Advisor would be liable for organizational and offering costs incurred by the Company of approximately $1.8 million . Approximately $0.7 million of organizational and offering costs the Advisor is liable for as of September 30, 2018 is deducted from "Due to Affiliates" and the remaining $1.1 million is included in "Other Assets, net" on the consolidated balance sheet. Organizational and offering costs incurred as of September 30, 2018 , including those incurred by the Company and due to the Advisor, for the Follow-On Offering are as follows: September 30, 2018 Cumulative offering costs $ 2,806 Cumulative organizational costs $ 510 Organizational and offering costs advanced by the Advisor $ 1,998 Organizational and offering costs paid by the Company 1,318 Adjustment to organizational and offering costs pursuant to the limitation: Costs in excess of limit (1,820 ) Organizational and offering costs incurred $ 1,496 Distribution Reinvestment Plan (DRP) The Company has adopted the DRP, which allows stockholders to have dividends and other distributions otherwise distributable to them invested in additional shares of common stock. No sales commissions or dealer manager fees are paid on shares sold through the DRP. The Company may amend or terminate the DRP for any reason at any time upon 10 days ' prior written notice to stockholders, which may be provided through the Company's filings with the SEC. IPO Share Redemption Program The Company had a share redemption program for holders of Class A, Class AA, and Class AAA shares ("IPO Shares") who held their shares for less than four years, which enabled IPO stockholders to sell their shares back to the Company in limited circumstances ("IPO Share Redemption Program"). On June 4, 2018, the board of directors of the Company approved the termination of the IPO Share Redemption Program effective as of July 5, 2018. In addition, effective as of such date, the board of directors amended and restated the New Share Redemption Program in order to allow stockholders of the IPO Shares to utilize the New Share Redemption Program. Accordingly, beginning in July 2018, stockholders of IPO Shares are able to continue to redeem at 100% of the NAV of the applicable share class, subject to the other limitations and conditions of the amended and restated New Share Redemption Program, as noted below. Redemption requests must be received by 4:00 p.m. (Eastern time) on the second to last business day of the applicable quarter. During the three and nine months ended September 30, 2018 and 2017 , the Company redeemed shares of its outstanding common stock under the IPO Share Redemption Program as follows: Three Months Ended September 30, Nine Months Ended September 30, Period 2018 2017 2018 2017 Shares of common stock redeemed 585,525 (1) 146,083 1,306,834 413,842 Weighted average price per share $ 9.65 $ 9.06 $ 9.36 $ 9.18 (1) Second quarter requests redeemed in the third quarter. During the nine months ended September 30, 2018 , the Company redeemed 1,306,834 shares of common stock under the IPO Share Redemption Program for approximately $12.2 million at a weighted average price per share of 9.36 . Since inception, the Company has honored all redemption requests related to the IPO Share Redemption Program and has redeemed a total of 2,097,775 shares of common stock for approximately $19.6 million at a weighted average price per share of $9.34 . The Company has funded all redemptions using proceeds from the sale of IPO Shares pursuant to the DRP. For more information regarding the IPO Share Redemption Program, see our Annual Report on Form 10-K for the year ended December 31, 2017. New Share Redemption Program In connection with the Follow-On Offering, the Company’s board of directors adopted the New Share Redemption Program for the New Shares (and IPO Shares that have been held for four years or longer). As noted above, subsequently, on June 4, 2018, the board of directors amended and restated the program to allow stockholders of the IPO Shares to utilize the New Share Redemption Program, effective as of July 5, 2018. Under the New Share Redemption Program, the Company will redeem shares as of the last business day of each quarter. The redemption price will be equal to the NAV per share for the applicable class generally on the 13th of the month prior to quarter end. Redemption requests must be received by 4:00 p.m. (Eastern time) on the second to last business day of the applicable quarter. Redemption requests exceeding the quarterly cap will be filled on a pro rata basis.With respect to any pro rata treatment, redemption requests following the death or qualifying disability of a stockholder will be considered first, as a group, followed by requests where pro rata redemption would result in a stockholder owning less than the minimum balance of $2,500 of shares of the Company's common stock, which will be redeemed in full to the extent there are available funds, with any remaining available funds allocated pro rata among all other redemption requests. All unsatisfied redemption requests must be resubmitted after the start of the next quarter, or upon the recommencement of the New Share Redemption Program, as applicable. There are several restrictions under the New Share Redemption Program. Stockholders generally have to hold their shares for one year before submitting their shares for redemption under the program; however, the Company will waive the one-year holding period in the event of the death or qualifying disability of a stockholder. Shares issued pursuant to the DRP are not subject to the one-year holding period. In addition, the New Share Redemption Program generally imposes a quarterly cap on aggregate redemptions of the Company's shares equal to a value of up to 5% of the aggregate NAV of the outstanding shares as of the last business day of the previous quarter. As the value on the aggregate redemptions of the Company's shares is outside the Company's control, the 5% quarterly cap is considered to be temporary equity and is presented as the common stock subject to redemption on the accompanying consolidated balance sheets. As of September 30, 2018 , the quarterly cap was approximately $37.4 million and $6.7 million of common stock was reclassified from common stock to accrued expenses and other liabilities in the consolidated balance sheet as of September 30, 2018 . During the three and nine months ended September 30, 2018 and 2017 , the Company redeemed shares of its outstanding common stock under the New Share Redemption Program as follows: Three Months Ended September 30, Nine Months Ended September 30, Period 2018 2017 2018 2017 Shares of common stock redeemed 693,487 — 693,487 — Weighted average price per share $ 9.62 — $ 9.62 — Since inception, the Company has honored all redemption requests related to the New Share Redemption Program and has redeemed a total of 693,487 shares of common stock for approximately $6.7 million at a weighted average price per share of $9.62 . The Company’s board of directors has the right to modify or suspend the New Share Redemption Program upon 30 days ' notice at any time if it deems such action to be in the Company’s best interest. Any such modification or suspension will be communicated to stockholders through the Company’s filings with the SEC.	Equity Status of Offerings On January 20, 2017, the Company closed the primary portion of the IPO; however, the Company continued to offer shares pursuant to the DRP. On April 6, 2017, the Company filed a Registration Statement on Form S-3 with the SEC for the registration of 3.0 million shares for sale pursuant to the DRP. The DRP may be terminated at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company’s filings with the SEC. On September 20, 2017, the Company commenced a follow-on offering of up to $2.2 billion of shares, consisting of up to $2.0 billion of shares in the Company’s primary offering and $0.2 billion of shares pursuant to the DRP. The Company reclassified all Class T and Class I shares sold in the IPO as “Class AA” and “Class AAA” shares, respectively. The Company is offering Class T shares, Class S shares, Class D shares and Class I shares in its follow-on offering. Share Classes Class T shares, Class S shares, Class D shares, Class I shares, Class A shares, Class AA shares and Class AAA shares vote together as a single class, and each share is entitled to one vote on each matter submitted to a vote at a meeting of the Company’s stockholders; provided that with respect to any matter that would only have a material adverse effect on the rights of a particular class of common stock, only the holders of such affected class are entitled to vote. The following table summarizes shares issued and gross proceeds received for each share class as of December 31, 2017 and outstanding shares as of December 31, 2017 and 2016 : Class T S D I A AA AAA Total Gross proceeds from primary portion of offerings $ 41 $ 3 $ 3 $ 2,493 $ 240,780 $ 474,858 $ 8,379 $ 726,557 Gross proceeds from DRP $ — $ — $ — $ 41 $ 19,773 $ 21,828 $ 312 $ 41,954 Shares issued in primary portion of offerings 4,144 264 264 263,200 24,199,760 47,562,870 901,225 72,931,727 DRP shares issued 4 4 4 4,276 2,089,748 2,313,170 33,308 4,440,514 Stock distribution shares issued — — — — 263,641 300,166 4,676 568,483 Restricted stock units issued — — — — — — 25,500 25,500 Total redemptions — — — — (557,206 ) (233,735 ) — (790,941 ) Total shares outstanding as of 12/31/2017 4,148 268 268 267,476 25,995,943 49,942,471 964,709 77,175,283 Total shares outstanding as of 12/31/2016 — — — — 25,562,982 44,595,631 781,034 70,939,647 Offering and Organizational Costs Pursuant to the Advisory Agreement, in no event will the Company be obligated to reimburse the Advisor for organizational and offering costs incurred in connection with the follow-on offering totaling in excess of 15% (including selling commissions, dealer manager fees, distribution fees and non-accountable due diligence expense allowance but excluding acquisition expenses or any fees, if ever applicable) of the gross proceeds raised in the follow-on offering (excluding gross proceeds from the DRP). If the organizational and offering costs exceed such limits discussed above, within 60 days after the end of the month in which the follow-on offering terminates or is completed, the Advisor is obligated to reimburse the Company for any excess amounts. As long as the Company is subject to the Statement of Policy Regarding Real Estate Investment Trusts published by the North American Securities Administrators Association (“NASAA REIT Guidelines”), such limitation discussed above will also apply to any future public offerings. As of December 31, 2017 , organizational and offering costs relating to the follow-on offering were 81.0% of gross offering proceeds, including selling commissions, dealer manager fees and distribution fees. Therefore, if the follow-on offering was terminated on December 31, 2017 , the Advisor would be liable for organizational and offering costs incurred by the Company of approximately $1.7 million . Approximately $1.0 million of organizational and offering costs the Advisor is liable for as of December 31, 2017 is deducted from “Due to Affiliates” and the remaining $0.7 million is included in “Other Assets, net” on the consolidated balance sheet. Organizational and offering costs incurred as of December 31, 2017 , including those incurred by the Company and due to the Advisor, for the follow-on offering are as follows: December 31, 2017 Cumulative offering costs $ 1,698 Cumulative organizational costs $ 359 Organizational and offering costs advanced by the Advisor $ 1,226 Organizational and offering costs paid by the Company 831 Adjustment to organizational and offering costs pursuant to the limitation: Reduction in due to affiliates (999 ) Due from affiliates (677 ) Net due to Advisor $ 381 As of December 31, 2017 , organizational and offering costs incurred by the Company related to the IPO were approximately $76.0 million . In addition, the total outstanding amounts of the Contingent Advisor Payment Holdback as of December 31, 2017 and 2016 were $0.1 million and $5.4 million , respectively. Amendment and Restatement of Distribution Reinvestment Plan In connection with the follow-on offering, on September 8, 2017, the Company’s board of directors amended and restated the DRP effective as of September 30, 2017, to include the New Shares under the DRP. The amended and restated DRP allows stockholders to have distributions otherwise distributable to them invested in additional shares of common stock of the same class. No selling commissions, dealer manager fees or stockholder servicing fees are paid on shares sold through the DRP, but the DRP shares will be charged the applicable distribution fee payable with respect to all shares of the applicable class. The purchase price per share under the DRP is equal to the NAV per share applicable to the class of shares purchased, calculated as of the distribution date. IPO Shares - Share Redemption Program The Company has a share redemption program for holders of Class A, Class AA, and Class AAA shares (“IPO Shares”) who have held their shares for less than four years, which enables IPO stockholders to sell their shares back to the Company in limited circumstances (“IPO Share Redemption Program”). The Company’s IPO Share Redemption Program permits stockholders to submit their IPO Shares for redemption after they have held them for at least one year, subject to the significant conditions and limitations described below. There are several restrictions under the IPO Share Redemption Program. A stockholder generally has to hold his or her shares for one year before submitting shares for redemption under the program; however, the Company may waive the one-year holding period in the event of the death, qualifying disability or bankruptcy of a stockholder. In addition, the Company will limit the number of IPO Shares redeemed pursuant to the IPO Share Redemption Program as follows: (1) during any calendar year, the Company will not redeem in excess of 5% of the weighted average number of IPO Shares outstanding during the prior calendar year; and (2) funding for the redemption of shares will be limited to the amount of net proceeds the Company receives from the sale of IPO Shares under the Company’s DRP. These limits may prevent the Company from accommodating all requests made in any year. In addition, stockholders holding IPO Shares for four years or longer will be eligible to utilize the New Share Redemption Program, and redeem at 100% of the NAV of the applicable share class. The IPO Share Redemption Program will terminate in January 2021 on the four year anniversary of the termination of the primary portion of the Company’s IPO. During the years ended ended December 31, 2017 and 2016 , the Company redeemed shares of its outstanding common stock as follows: Year Ended December 31, Period 2017 2016 Shares of common stock redeemed 623,499 167,442 Weighted average price per share $ 9.21 $ 9.72 During the year ended December 31, 2016, the Company redeemed 167,442 shares of common stock for approximately $1.6 million at a weighted average price per share of $9.72 . During the year ended December 31, 2017, the Company redeemed 623,499 shares of common stock for approximately $5.7 million at a weighted average price per share of $9.21 . Since inception, the Company has honored all redemption requests and has redeemed a total of 790,941 shares of common stock for approximately $7.4 million at a weighted average price per share of $9.32 . The Company has funded all redemptions using proceeds from the sale of IPO Shares pursuant to the DRP. As long as the common stock is not listed on a national securities exchange or over-the-counter market, stockholders who have held their stock for at least one year may be able to have all or a portion consisting of at least 25% of their shares of stock redeemed by the Company. Share redemption requests must be received by the Company no later than the last business day of the calendar quarter, and shares generally will be redeemed on the last business day of the month following such calendar quarter. The redemption price per IPO Share is expected to be the redemption rate set forth in the following table which is based upon the number of years the stock is held: Number Years Held Redemption Price per Share Less than 1 year No Redemption Allowed After one year from the purchase date 90.0% of the Redemption Amount (as defined below) After two years from the purchase date 95.0% of the Redemption Amount After three years from the purchase date 97.5% of the Redemption Amount After four years from the purchase date 100.0% of the Redemption Amount The Redemption Amount for shares purchased under the Company’s IPO Share Redemption Program shall be the lesser of (i) the amount the stockholder paid for their shares or (ii) the NAV of the shares. Shares redeemed in connection with the death or qualifying disability of a stockholder may be repurchased at the purchase price of such shares. The redemption price per share will be reduced by the aggregate amount of net proceeds per share, if any, distributed to the stockholders prior to the repurchase date as a result of a “special distribution.” While the board of directors does not have specific criteria for determining a special distribution, the Company expects that a special distribution will only occur upon the sale of a property and the subsequent distribution of the net sale proceeds. The redemption price per share is subject to adjustment as determined from time to time by the board of directors. The Company’s board of directors may choose to amend, suspend, or terminate the IPO Share Redemption Program upon 30 days’ written notice at any time, which may be provided through the Company’s filings with the SEC. If the Company cannot purchase all shares presented for redemption in any quarter, based upon insufficient cash available or the limit on the number of shares the Company may redeem during any calendar year, the Company will attempt to honor redemption requests on a pro rata basis. With respect to any pro rata treatment, redemption requests following the death or qualifying disability of a stockholder will be considered first, as a group, followed by requests where pro rata redemption would result in a stockholder owning less than the minimum balance of $2,500 of shares of common stock, which will be redeemed in full to the extent there are available funds, with any remaining available funds allocated pro rata among all other redemption requests. The Company will treat the unsatisfied portion of the redemption request as a request for redemption the following quarter. Such pending requests will generally be honored on a pro rata basis. Any stockholder request to cancel an outstanding redemption must be sent to the Company’s transfer agent prior to the last day of the new quarter. The Company will determine whether sufficient funds are available or the IPO Share Redemption Program has reached the 5% share limit as soon as practicable after the end of each quarter, but in any event prior to the applicable payment date. As the use of the proceeds from the DRP related to the IPO shares for redemptions is outside the Company’s control, the net proceeds from the DRP related to the IPO Shares are considered to be temporary equity and are presented as common stock subject to redemption on the accompanying consolidated balance sheets. The cumulative proceeds from the DRP related to the IPO Shares, net of any redemptions, will be computed at each reporting date and will be classified as temporary equity on the Company’s consolidated balance sheets. As noted above, the redemption is limited to proceeds from new permanent equity from the sale of shares pursuant to the Company’s DRP related to the IPO Shares. As of December 31, 2017 , $ 32.4 million of common stock was available for redemption and $2.2 million of common stock was reclassified from redeemable common stock to accrued expenses and other liabilities in the consolidated balance sheet as of December 31, 2017 . New Share Redemption Program In connection with the follow-on offering, the Company’s board of directors adopted the New Share Redemption Program for the New Shares (and IPO Shares that have been held for four years or longer). Under the New Share Redemption Program, the Company will redeem shares as of the last business day of each quarter. The redemption price will be equal to the NAV per share for the applicable class generally on the 13th of the month immediately prior to the end of the applicable quarter. Redemption requests exceeding the quarterly cap will be filled on a pro rata basis. With respect to any pro rata treatment, redemption requests following the death or qualifying disability of a stockholder will be considered first, as a group, followed by requests where pro rata redemption would result in a stockholder owning less than the minimum balance of $2,500 of shares of the Company’s common stock, which will be redeemed in full to the extent there are available funds, with any remaining available funds allocated pro rata among all other redemption requests. All unsatisfied redemption requests must be resubmitted after the start of the next quarter, or upon the recommencement of the New Share Redemption Program, as applicable. There are several restrictions under the New Share Redemption Program. Stockholders generally have to hold their shares for one year before submitting their shares for redemption under the program; however, the Company will waive the one -year holding period in the event of the death or qualifying disability of a stockholder. Shares issued pursuant to the DRP are not subject to the one -year holding period. In addition, the New Share Redemption Program generally imposes a quarterly cap on aggregate redemptions of the New Shares (and IPO shares that have been held for four years or longer) equal to a value of up to 5% of the aggregate NAV of the outstanding shares of such classes as of the last business day of the previous quarter. As the value on the aggregate redemptions of the New Shares is outside the Company’s control, the 5% quarterly cap is considered to be temporary equity and is presented as the common stock subject to redemption on the accompanying consolidated balance sheets. For the quarter ended December 31, 2017 , the quarterly cap was zero . The Company’s board of directors has the right to modify or suspend the New Share Redemption Program upon 30 days’ notice at any time if it deems such action to be in the Company’s best interest and the best interest of the Company’s stockholders. Any such modification or suspension will be communicated to stockholders through the Company’s filings with the SEC. Share-Based Compensation The Company’s board of directors adopted an Employee and Director Long-Term Incentive Plan (the “Plan”), which provides for the grant of awards to the Company’s directors and full-time employees (should the Company ever have employees), directors and full-time employees of the Advisor and affiliate entities that provide services to the Company, and certain consultants that provide services to the Company, the Advisor, or affiliate entities. Awards granted under the Plan may consist of stock options, restricted stock, stock appreciation rights, distribution equivalent rights and other equity-based awards. The stock-based payment will be measured at fair value and recognized as compensation expense over the vesting period. The term of the Plan is ten years and the total number of shares of common stock reserved for issuance under the Plan will be equal to 10% of the outstanding shares of stock at any time, not to exceed 10,000,000 shares in the aggregate. As of December 31, 2017 , approximately 7,717,528 shares were available for future issuance under the Plan. During the first quarter of 2017, the Company issued an aggregate of 15,000 shares of restricted stock to the Company’s independent directors. These restricted shares were fully vested upon issuance. On June 14, 2017, the Company issued 7,000 shares of restricted stock to each of the Company’s independent directors upon each of their respective re-elections to the Company’s board of directors. Half of the restricted shares vested upon issuance, and the remaining half will vest upon the first anniversary of the grant date, subject to the independent director’s continued service as a director during such vesting period. The Company measured and began recognizing director compensation expense for the 36,000 shares of restricted stock granted during 2017, subject to the vesting period. Distributions Earnings and profits, which determine the taxability of distributions to stockholders, may differ from income reported for financial reporting purposes due to the differences for federal income tax purposes in the treatment of loss on debt, revenue recognition and compensation expense and in the basis of depreciable assets and estimated useful lives used to compute depreciation expense. The following unaudited table summarizes the federal income tax treatment for all distributions per share for the years ended December 31, 2017 , 2016 and 2015 reported for federal tax purposes and serves as a designation of capital gain distributions, if applicable, pursuant to Section 857(b)(3)(c) of the Code and Treasury Regulation § 1.857-6(e). Year Ended December 31, 2017 2016 2015 Ordinary income $ 0.04 7.90 % $ 0.31 57.10 % $ 0.21 38.60 % Return of capital 0.51 92.10 % 0.24 42.90 % 0.34 61.40 % Total distributions paid $ 0.55 100.00 % $ 0.55 100.00 % $ 0.55 100.00 %
Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Equity	Equity Common Equity As of September 30, 2018 , the Company had received aggregate gross offering proceeds of approximately $1.5 billion from the sale of shares in the Private Offering, the Public Offerings, and the DRP Offerings, as discussed in Note 1, Organization . There were 166,253,534 shares outstanding at September 30, 2018 , including shares issued pursuant to the DRP, less shares redeemed pursuant to the SRP discussed below. Distribution Reinvestment Plan (DRP) The Company has adopted the DRP, which allows stockholders to have dividends and other distributions otherwise distributable to them invested in additional shares of common stock. No sales commissions or dealer manager fee will be paid on shares sold through the DRP. The Company may amend or terminate the DRP for any reason at any time upon 10 days' prior written notice to stockholders, which may be provided through the Company's filings with the SEC. As of September 30, 2018 and December 31, 2017 , the Company had issued approximately $245.6 million and $211.9 million , respectively, in shares pursuant to the DRP, which are classified on the consolidated balance sheets as common stock subject to redemption, net of redemptions paid of approximately $234.6 million , and redemptions payable totaling approximately $6.7 million and $20.4 million , respectively. Share Redemption Program The Company has adopted the SRP that enables stockholders to sell their stock to the Company in limited circumstances. As long as the common stock is not listed on a national securities exchange or over-the-counter market, stockholders who have held their stock for at least one year may, under certain circumstances, be able to have all or any portion of their shares of stock redeemed by the Company. Only those stockholders who purchased their shares from the Company or received their shares from the Company (directly or indirectly) through one or more non-cash transactions may be able to participate in the SRP. During any calendar year, the Company will not redeem more than 5% of the weighted average number of shares outstanding during the prior calendar year. The cash available for redemption will be limited to the proceeds from the sale of shares pursuant to the DRP. If the Company cannot purchase all shares presented for redemption in any quarter, based upon insufficient cash available or the limit on the number of shares the Company may redeem during any calendar year, the Company will attempt to honor redemption requests on a pro rata basis. With respect to any pro rata treatment, redemption requests following the death or qualifying disability of a stockholder will be considered first, as a group, followed by requests where pro rata redemption would result in a stockholder owning less than the minimum balance of two thousand five hundred dollars of shares of common stock, which will be redeemed in full to the extent there are available funds, with any remaining available funds allocated pro rata among all other redemption requests. The Company will treat the unsatisfied portion of the redemption request as a request for redemption the following quarter. Such pending requests will generally be honored on a pro rata basis. Any stockholder request to cancel an outstanding redemption must be sent to the Company's transfer agent prior to the last day of the new quarter. The Company will determine whether sufficient funds are available or the SRP has reached the 5% share limit as soon as practicable after the end of each quarter, but in any event prior to the applicable payment date. As the use of the proceeds from the DRP for redemptions is outside the Company’s control, the net proceeds from the DRP are considered to be temporary equity and are presented as common stock subject to redemption on the accompanying consolidated balance sheets. The cumulative proceeds from the DRP, net of any redemptions, will be computed at each reporting date and will be classified as temporary equity on the Company’s consolidated balance sheets. As noted above, the SRP is limited to proceeds from new permanent equity from the sale of shares pursuant to the DRP. Pursuant to the SRP, the redemption price per share shall be the lesser of (i) the amount paid for the shares or (ii) 95% of the NAV of the shares. Shares redeemed in connection with the death or qualifying disability of a stockholder may be repurchased at 100% of the NAV of the shares. The redemption price per share will be as of the last business day of the applicable quarter. Redemption requests will be honored on or about the last business day of the month following the end of each quarter. Requests for redemption must be received on or prior to the end of the quarter in order for the Company to repurchase the shares as of the end of the following month. The following table summarizes share redemption activity during the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Shares of common stock redeemed 1,311,582 2,936,150 8,013,521 6,155,290 Weighted average price per share $ 9.63 $ 9.97 $ 9.60 $ 9.98 During the three months ended September 30, 2018 , the Company received requests for the redemption of common stock of 4,083,881 shares, which exceeded the annual limitation of 5% of the weighted average number of shares outstanding during the prior calendar year by 3,401,249 shares or approximately $32.4 million . T he Company is not obligated to redeem any amounts in excess of the limitations until 2019, when the 5% share limitation is reset and to the extent DRP proceeds are available. The Company processed the redemption requests according to the SRP policy described above and redeemed 16.7% of the shares requested at a weighted average price per share of $9.76 and carried forward the unprocessed requests. As a result, standard redemption requests for the quarter ended September 30, 2018 were processed on a pro-rata basis and were paid out on October 31, 2018. During the nine months ended September 30, 2018 , the Company redeemed 8,013,521 shares of common stock for approximately $76.9 million at a weighted average price per share of $9.60 pursuant to the SRP. Since inception and through September 30, 2018 , the Company had redeemed 23,863,419 shares of common stock for approximately $234.6 million at a weighted average price per share of $9.83 pursuant to the SRP. Since inception and through June 30, 2018, the Company honored all redemption requests. Noncontrolling Interests Noncontrolling interests represent limited partnership interests in the Operating Partnership in which the Company is the general partner. General partnership units and limited partnership units of the Operating Partnership were issued as part of the initial capitalization of the Operating Partnership, and limited partnership units were issued in conjunction with management's contribution of certain assets, as well as other contributions, as discussed in Note 1, Organization . As of September 30, 2018 , noncontrolling interests were approximately 3.62% of total shares and 3.58% of weighted average shares outstanding (both measures assuming limited partnership units were converted to common stock). The Company has evaluated the terms of the limited partnership interests in the Operating Partnership and as a result, has classified limited partnership interests issued in the initial capitalization and in conjunction with the contributed assets as noncontrolling interests, which are presented as a component of permanent equity, except as discussed below. The Company evaluates individual noncontrolling interests for the ability to recognize the noncontrolling interest as permanent equity on the consolidated balance sheets at the time such interests are issued and on a continual basis. Any noncontrolling interest that fails to qualify as permanent equity has been reclassified as temporary equity and adjusted to the greater of (a) the carrying amount or (b) its redemption value as of the end of the period in which the determination is made. The Operating Partnership issued 6.6 million limited partnership units to affiliated parties and unaffiliated third parties in exchange for certain properties and 0.1 million limited partnership units to unaffiliated third parties unrelated to property contributions. To the extent the contributors should elect to redeem all or a portion of their Operating Partnership units, pursuant to the terms of the respective contribution agreement, such redemption shall be at a per unit value equivalent to the price at which the contributor acquired its limited partnership units in the respective transaction. The limited partners of the Operating Partnership, other than those related to the Will Partners REIT, LLC ("Will Partners" property) contribution, will have the right to cause the general partner of the Operating Partnership, the Company, to redeem their limited partnership units for cash equal to the value of an equivalent number of shares, or, at the Company’s option, purchase their limited partnership units by issuing one share of the Company’s common stock for the original redemption value of each limited partnership unit redeemed. The Company has the control and ability to settle in shares. These rights may not be exercised under certain circumstances which could cause the Company to lose its REIT election. There were no unit redemption requests during the nine months ended September 30, 2018 and year ended December 31, 2017 . The following summarizes the activity for noncontrolling interests recorded as equity for the nine months ended September 30, 2018 and year ended December 31, 2017 : Nine Months Ended September 30, 2018 Year Ended December 31, 2017 Beginning balance $ 31,105 $ 30,114 Distributions to noncontrolling interests (3,267 ) (4,369 ) Allocated distributions to noncontrolling interests subject to redemption (10 ) (13 ) Net income 671 5,120 Other comprehensive income 224 253 Ending balance $ 28,723 $ 31,105 Noncontrolling interests subject to redemption Operating partnership units issued pursuant to the Will Partners property contribution are not included in permanent equity on the consolidated balance sheets. The partners holding these units can cause the general partner to redeem the units for the cash value, as defined in the operating partnership agreement. As the general partner does not control these redemptions, these units are presented on the consolidated balance sheets as noncontrolling interest subject to redemption at their redeemable value. The net income (loss) and distributions attributed to these limited partners is allocated proportionately between common stockholders and other noncontrolling interests that are not considered redeemable.	Equity Common Equity As of December 31, 2017 , the Company had received aggregate gross offering proceeds of approximately $1.5 billion from the sale of shares in the Private Offering, the Public Offerings, and the DRP Offerings, as discussed in Note 1, Organization . There were 170,906,111 shares outstanding at December 31, 2017 , including shares issued pursuant to the DRP, less shares redeemed pursuant to the SRP discussed below. Distribution Reinvestment Plan (DRP) The Company has adopted the DRP, which allows stockholders to have dividends and other distributions otherwise distributable to them invested in additional shares of common stock. No sales commissions or dealer manager fee will be paid on shares sold through the DRP. The Company may amend or terminate the DRP for any reason at any time upon 10 days’ prior written notice to stockholders, which may be provided through the Company’s filings with the SEC. As of December 31, 2017 and 2016 , the Company had issued approximately $211.9 million and $162.4 million , respectively, in shares pursuant to the DRP, which are classified on the consolidated balance sheets as common stock subject to redemption, net of redemptions paid of approximately $157.7 million and $58.8 million , respectively, and redemptions payable totaling approximately $20.4 million and $11.6 million . Share Redemption Program The Company has adopted the SRP that enables stockholders to sell their stock to the Company in limited circumstances. As long as the common stock is not listed on a national securities exchange or over-the-counter market, stockholders who have held their stock for at least one year may, under certain circumstances, be able to have all or any portion of their shares of stock redeemed by the Company. During any calendar year, the Company will not redeem more than 5% of the weighted average number of shares outstanding during the prior calendar year. The cash available for redemption will be limited to the proceeds from the sale of shares pursuant to the DRP. If the Company cannot purchase all shares presented for redemption in any quarter, based upon insufficient cash available or the limit on the number of shares the Company may redeem during any calendar year, the Company will attempt to honor redemption requests on a pro rata basis. With respect to any pro rata treatment, redemption requests following the death or qualifying disability of a stockholder will be considered first, as a group, followed by requests where pro rata redemption would result in a stockholder owning less than the minimum balance of $2,500 of shares of common stock, which will be redeemed in full to the extent there are available funds, with any remaining available funds allocated pro rata among all other redemption requests. The Company will treat the unsatisfied portion of the redemption request as a request for redemption the following quarter. Such pending requests will generally be honored on a pro rata basis. Any stockholder request to cancel an outstanding redemption must be sent to the Company’s transfer agent prior to the last day of the new quarter. The Company will determine whether sufficient funds are available or the SRP has reached the 5.0% share limit as soon as practicable after the end of each quarter, but in any event prior to the applicable payment date. As the use of the proceeds from the DRP for redemptions is outside the Company’s control, the net proceeds from the DRP are considered to be temporary equity and are presented as common stock subject to redemption on the accompanying consolidated balance sheets. The cumulative proceeds from the DRP, net of any redemptions, will be computed at each reporting date and will be classified as temporary equity on the Company’s consolidated balance sheets. As noted above, the SRP is limited to proceeds from new permanent equity from the sale of shares pursuant to the DRP. Pursuant to the SRP, the redemption price per share shall be the lesser of (i) the amount paid for the shares or (ii) 95% of the NAV of the shares. Shares redeemed in connection with the death or qualifying disability of a stockholder may be repurchased at 100% of the NAV of the shares. The redemption price per share will be as of the last business day of the applicable quarter. Redemption requests will be honored on or about the last business day of the month following the end of each quarter. Requests for redemption must be received on or prior to the end of the quarter in order for the Company to repurchase the shares as of the end of the following month. The following table summarizes share redemption activity during the years ended December 31, 2017 and 2016 : Year Ended December 31, 2017 2016 Shares of common stock redeemed 9,931,245 4,164,955 Weighted average price per share $ 9.96 $ 9.95 Since inception and through December 31, 2017 , the Company had redeemed 15,849,898 shares of common stock for approximately $157.7 million at a weighted average price per share of $9.95 pursuant to the SRP. Since inception and through June 30, 2017, the Company has honored all redemption requests. During the year ended December 31, 2016, the Company redeemed 4,164,955 shares of common stock for approximately $41.4 million at a weighted average price per share of $9.95 . During the year ended December 31, 2017, the Company redeemed 9,931,245 shares of common stock for approximately $98.9 million at a weighted average price per share of $9.96 . The Company has funded all redemptions using proceeds from the sale of shares pursuant to the DRP. During the three months ended September 30, 2017, the Company received requests for the redemption of common stock of approximately 3,878,396 shares, which exceeded the annual limitation of 5% of the weighted average number of shares outstanding during the prior calendar year by approximately 104,999 shares. The Company processed the redemption requests according to the SRP policy described above and redeemed 97% of the shares requested at a weighted average price per share of $9.92 . Those stockholders who were subject to pro rata treatment of their redemption requests had approximately 95% of their requests satisfied. The remaining portion of such requests will be carried forward to the next available redemption period. As the 5% maximum was reached for the quarter ended September 30, 2017, the Company did not process any redemption requests for the quarter ended December 31, 2017. The Company’s board of directors may choose to amend, suspend, or terminate the SRP upon 30 days’ written notice at any time, which may be provided through the Company’s filings with the SEC. Distributions Earnings and profits, which determine the taxability of distributions to stockholders, may differ from income reported for financial reporting purposes due to the differences for federal income tax purposes in the treatment of loss on debt, revenue recognition and compensation expense and in the basis of depreciable assets and estimated useful lives used to compute depreciation expense. The following unaudited table summarizes the federal income tax treatment for all distributions per share for the years ended December 31, 2017, 2016, and 2015 reported for federal tax purposes and serves as a designation of capital gain distributions, if applicable, pursuant to Internal Revenue Code Section 857(b)(3)(C) and Treasury Regulation §1.857-6(e). Year Ended December 31, 2017 2016 2015 Ordinary income $ 0.40 59 % $ 0.47 69 % $ 0.48 69 % Capital Gain 0.18 26 % — — % — — % Return of capital 0.10 15 % 0.21 31 % 0.21 31 % Total distributions paid $ 0.68 100 % $ 0.68 100 % $ 0.69 100 % Share-Based Compensation The Company has adopted an Employee and Director Long-Term Incentive Plan (the “Plan”) pursuant to which the Company may issue stock-based awards to its directors and full-time employees (should the Company ever have employees), executive officers and full-time employees of the Advisor and its affiliate entities that provide services to the Company, and certain consultants who provide significant services to the Company. The term of the Plan is 10 years and the total number of shares of common stock reserved for issuance under the Plan is 10% of the outstanding shares of stock at any time, not to exceed 10,000,000 shares in the aggregate. Awards granted under the Plan may consist of stock options, restricted stock, stock appreciation rights and other equity-based awards. The stock-based payment will be measured at fair value and recognized as compensation expense over the vesting period. Pursuant to the Plan, the Company issued 5,000 shares of restricted stock to each independent director on March 3, 2014 who was serving at that time and to Mr. Kripalani upon his appointment to the Company’s board of directors on January 31, 2017, which vested immediately upon grant. In addition, the compensation committee authorized an annual grant of 1,000 shares of restricted stock to each of the Company’s independent directors with a vesting schedule of three years . Upon re-election of each independent director at the 2014, 2015, and 2016 annual stockholders’ meetings, the Company measured and began recognizing director compensation expense for the 1,000 shares of restricted stock granted each year, subject to the vesting period. Pursuant to the Director Compensation Plan, adopted by the compensation committee on March 8, 2017, upon re-election of each independent director at the June 14, 2017 annual stockholders’ meeting, the Company granted 7,000 shares of restricted common stock to each of the independent directors. Half of the restricted shares vested upon issuance, and the remaining half will vest upon the first anniversary of the grant date, subject to the independent director’s continued service as a director during such vesting period. The fair value of such issuance was estimated at $10.44 per share, the then current price paid to acquire a share of the Company’s common stock pursuant to the 2017 DRP Offering. Immediately upon granting the restricted common stock, the Company measured and began recognizing director compensation expense, subject to the vesting period. 13,000 restricted shares vested during the year ended December 31, 2017, which were part of the 2014, 2015, 2016, and 2017 grants. The fair value of the restricted shares granted in 2014 was estimated at $10.28 per share; additionally, the fair value of the restricted shares granted in 2015 and 2016 was $10.40 , the then most recent price paid to acquire a share of the Company’s common stock. All issuances of restricted stock are entitled to dividends upon vesting of the shares. Noncontrolling Interests Noncontrolling interests represent limited partnership interests in the Operating Partnership in which the Company is the general partner. General partnership units and limited partnership units of the Operating Partnership were issued as part of the initial capitalization of the Operating Partnership, and limited partnership units were issued in conjunction with management’s contribution of certain assets, as well as other contributions, as discussed in Note 1, Organization . As of December 31, 2017 , noncontrolling interests were approximately 4% of total shares and weighted average shares outstanding (both measures assuming limited partnership units were converted to common stock). The Company has evaluated the terms of the limited partnership interests in the Operating Partnership and as a result, has classified limited partnership interests issued in the initial capitalization and in conjunction with the contributed assets as noncontrolling interests, which are presented as a component of permanent equity, except as discussed below. The Company evaluates individual noncontrolling interests for the ability to recognize the noncontrolling interest as permanent equity on the consolidated balance sheets at the time such interests are issued and on a continual basis. Any noncontrolling interest that fails to qualify as permanent equity has been reclassified as temporary equity and adjusted to the greater of (a) the carrying amount or (b) its redemption value as of the end of the period in which the determination is made. The Operating Partnership issued 6.6 million limited partnership units to affiliated parties and unaffiliated third parties in exchange for certain properties and 0.1 million limited partnership units to unaffiliated third parties unrelated to property contributions. To the extent the contributors should elect to redeem all or a portion of their Operating Partnership units, pursuant to the terms of the respective contribution agreement, such redemption shall be at a per unit value equivalent to the price at which the contributor acquired its limited partnership units in the respective transaction. The limited partners of the Operating Partnership, other than those related to the Will Partners REIT, LLC (“Will Partners” property) contribution, will have the right to cause the general partner of the Operating Partnership, the Company, to redeem their limited partnership units for cash equal to the value of an equivalent number of shares of common stock, or, at the Company’s option, purchase their limited partnership units by issuing one share of the Company’s common stock for the original redemption value of each limited partnership unit redeemed. These rights may not be exercised under certain circumstances which could cause the Company to lose its REIT election. There were no redemption requests during the year ended December 31, 2017 and year ended December 31, 2016 . The following summarizes the activity for noncontrolling interests recorded as equity for the years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, 2017 2016 2015 Beginning balance $ 30,114 $ 21,318 $ 17,478 Contribution/issuance of noncontrolling interests — 11,941 7,282 Distributions to noncontrolling interests (4,369 ) (4,124 ) (3,150 ) Allocated distributions to noncontrolling interests subject to redemption (13 ) (11 ) (10 ) Net income 5,120 912 (138 ) Other comprehensive income (loss) 253 78 (144 ) Ending balance $ 31,105 $ 30,114 $ 21,318 Noncontrolling Interests Subject to Redemption Operating Partnership units issued pursuant to the Will Partners property contribution are not included in permanent equity on the consolidated balance sheets. The partners holding these units can cause the general partner of the Operating Partnership to redeem the units for the cash value, as defined in the operating partnership agreement. As the general partner of the Operating Partnership does not control these redemptions, these units are presented on the consolidated balance sheets as noncontrolling interest subject to redemption at their redeemable value. The net income (loss) and distributions attributed to these limited partners is allocated proportionately between common stockholders and other noncontrolling interests that are not considered redeemable.

Noncontrolling Interest (Notes)

Noncontrolling Interest (Notes)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Noncontrolling Interest [Abstract]
Noncontrolling Interest Disclosure [Text Block]	Noncontrolling Interests Noncontrolling interests represent limited partnership interests in the Operating Partnership in which the Company is the general partner. The Operating Partnership issued 20,000 Class A limited partnership units for $10 .00 per unit on February 11, 2014 to the Advisor in exchange for the initial capitalization of the Operating Partnership. On February 16, 2018, as elected by the Advisor, the Company issued 123,779 Operating Partnership units for $9.57 per unit to the Advisor for the 50% of the 2017 performance distribution allocation that the Advisor elected to receive in Class I limited partnership units. The remaining balance was paid in cash. As of September 30, 2018 , noncontrolling interests were approximately 0.18% of total shares outstanding and 0.16% of weighted average shares outstanding (both measures assuming limited partnership units were converted to common stock). The Company evaluates individual noncontrolling interests for the ability to recognize the noncontrolling interest as permanent equity on the consolidated balance sheets at the time such interests are issued and on a continual basis. Any noncontrolling interest that fails to qualify as permanent equity will be reclassified as temporary equity and adjusted to the greater of (a) the carrying amount, or (b) its redemption value as of the end of the period in which the determination is made. The limited partners of the Operating Partnership will have the right to cause the Operating Partnership to redeem their limited partnership units for cash equal to the value of an equivalent number of shares, or, at the Company’s option, the Company may purchase such limited partners' limited partnership units by issuing one share of common stock for each limited partnership unit redeemed. These rights may not be exercised under certain circumstances which could cause the Company to lose its REIT election. Furthermore, limited partners may generally exercise their redemption rights only after their limited partnership units have been outstanding for one year . The limited partnership units are reported on the consolidated balance sheets as noncontrolling interests. The following summarizes the activity for noncontrolling interests for the nine months ended September 30, 2018 and the year ended December 31, 2017 : Nine Months Ended September 30, 2018 Year Ended December 31, 2017 Beginning balance $ 76 $ 84 Issuance of limited partnership units 1,185 — Distributions to noncontrolling interests (50 ) (11 ) Net (loss) income allocation (1 ) 3 Other comprehensive loss (2 ) — Ending balance $ 1,208 $ 76	Noncontrolling Interests Noncontrolling interests represent limited partnership interests in the Operating Partnership. The Operating Partnership issued 20,000 limited partnership units for $10.00 per unit on February 11, 2014 to the Advisor in exchange for the initial capitalization of the Operating Partnership. As of December 31, 2017 , noncontrolling interests were approximately 0.03% of total shares outstanding and of weighted average shares outstanding (both measures assuming limited partnership units were converted to common stock). The Company evaluates individual noncontrolling interests for the ability to recognize the noncontrolling interest as permanent equity on the consolidated balance sheets at the time such interests are issued and on a continual basis. Any noncontrolling interest that fails to qualify as permanent equity will be reclassified as temporary equity and adjusted to the greater of (a) the carrying amount or (b) its redemption value as of the end of the period in which the determination is made. The limited partners of the Operating Partnership will have the right to cause the Operating Partnership to redeem their limited partnership units for cash equal to the value of an equivalent number of shares, or, at the Company’s option, the Company may purchase such limited partners’ limited partnership units by issuing one share of common stock for each limited partnership unit redeemed. These rights may not be exercised under certain circumstances which could cause the Company to lose its REIT election. Furthermore, limited partners may exercise their redemption rights only after their limited partnership units have been outstanding for one year. The limited partnership units are reported on the consolidated balance sheets as noncontrolling interests. The following summarizes the activity for noncontrolling interests for the years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, 2017 2016 2015 Beginning balance $ 84 $ 98 $ 139 Distributions to noncontrolling interests (11 ) (11 ) (11 ) Net income (loss) 3 (3 ) (30 ) Ending balance $ 76 $ 84 $ 98

Perpetual Convertible Preferred

Perpetual Convertible Preferred Equity	9 Months Ended
	Sep. 30, 2018
Griffin Capital Essential Asset REIT, Inc. [Member]
Temporary Equity [Line Items]
Perpetual Convertible Preferred Equity	Perpetual Convertible Preferred Shares On August 8, 2018, the Company entered into a purchase agreement (the "Purchase Agreement") with SHBNPP Global Professional Investment Type Private Real Estate Trust No. 13(H) (acting through Kookmin Bank as trustee)(the "Purchaser") and Shinhan BNP Paribas Asset Management Corporation, as an asset manager of the Purchaser, pursuant to which the Purchaser agreed to purchase an aggregate of 10,000,000 shares of Series A Cumulative Perpetual Convertible Preferred Stock, $0.001 par value per share, at a price of $25.00 per share (the "Series A Preferred Shares") in two tranches, each comprising 5,000,000 Series A Preferred Shares. On August 8, 2018 (the "First Issuance Date"), the Company issued 5,000,000 Series A Preferred Shares to the Purchaser for a total purchase price of $125.0 million (the "First Issuance"). The Company paid transaction fees totaling 3.5% of the First Issuance purchase price and incurred approximately $0.4 million in transaction-related expenses to third parties unaffiliated with the Company or the Sponsor. The Advisor incurred transaction-related expenses of approximately $0.2 million , which will be reimbursed by the Company. Pursuant to the Purchase Agreement, the Purchaser has agreed to purchase an additional 5,000,000 Series A Preferred Shares at a later date (the "Second Issuance Date") for an additional purchase price of $125.0 million subject to approval by the Purchaser’s internal investment committee and the satisfaction of the conditions in the Purchase Agreement, including, but not limited to, the execution of an Ownership Limit Exemption Agreement (the "Second Issuance"). Pursuant to the Purchase Agreement, the Purchaser is generally restricted from transferring the Series A Preferred Shares or the economic interest in the Series A Preferred Shares for a period of five years from the closing date. As redemption under certain circumstances (described below) are not solely within the Company's control, the Company classified the Series A Preferred Shares as temporary equity and are presented at their redemption value. The offering costs allocated to the Series A Preferred Shares are reductions to temporary equity. Distributions The Series A Preferred Shares are entitled to receive distributions quarterly in arrears at a rate equal to one-fourth (1/4) of the applicable varying rate, as follows: i. an initial annual distribution rate of 6.55% from and after the First Issuance Date, or if the Second Issuance occurs, 6.55% from and after the Second Issuance Date until the five year anniversary of the First Issuance Date, or if the Second Issuance occurs, the five year anniversary of the Second Issuance Date (the "Reset Date"), subject to paragraphs (iii) and (iv) below; ii. 6.75% from and after the Reset Date, subject to paragraphs (iii) and (iv) below; iii. if a listing ("Listing") of our shares of common stock or the Series A Preferred Shares on a national securities exchange registered under Section 6(a) of the Exchange Act, does not occur by August 1, 2020 (the "First Triggering Event"), 7.55% from and after August 2, 2020 and 7.75% from and after the Reset Date; or iv. if a Listing does not occur by August 1, 2021, 8.05% from and after August 2, 2021 until the Reset Date, and 8.25% from and after the Reset Date. Liquidation Preference Upon any voluntary or involuntary liquidation, dissolution or winding up of the Company, the holders of the Series A Preferred Shares will be entitled to be paid out of the Company's assets legally available for distribution to the stockholders, after payment of or provision for the Company's debts and other liabilities, liquidating distributions, in cash or property at its fair market value as determined by the Company's board of directors, in the amount, for each outstanding Series A Preferred Share equal to $25.00 per Series A Preferred Share (the "Liquidation Preference"), plus an amount equal to any accumulated and unpaid distributions to the date of payment, before any distribution or payment is made to holders of shares of common stock or any other class or series of equity securities ranking junior to the Series A Preferred Shares but subject to the preferential rights of holders of any class or series of equity securities ranking senior to the Series A Preferred Shares. After payment of the full amount of the Liquidation Preference to which they are entitled, plus an amount equal to any accumulated and unpaid distributions to the date of payment, the holders of Series A Preferred Shares will have no right or claim to any of our remaining assets. Company Redemption Rights The Series A Preferred Shares may be redeemed by the Company, in whole or in part, at the Company's option, upon the earlier to occur of: (i) five years from the First Issuance Date or (ii) the First Triggering Event, at a per share redemption price in cash equal to $25.00 per Series A Preferred Share (the "Redemption Price"), plus any accumulated and unpaid distributions on the Series A Preferred Shares up to the redemption date, plus, a redemption fee of 1.5% of the Redemption Price in the case of a redemption that occurs on or after the date of the First Triggering Event, but before the date that is five years from the First Issuance Date. Holder Redemption Rights In the event we fail to effect a Listing by August 1, 2023, the holder of any Series A Preferred Shares has the option to request a redemption of such shares on or on any date following August 1, 2023, at the Redemption Price, plus any accumulated and unpaid distributions up to the redemption date (the "Redemption Right"); provided, however, that no holder of the Series A Preferred Shares shall have a Redemption Right if a Listing occurs prior to or on August 1, 2023. Conversion Rights Subject to our redemption rights and certain conditions set forth in the articles supplementary, a holder of the Series A Preferred Shares, at his or her option, will have the right to convert such holder's Series A Preferred Shares into shares of the Company's common stock any time after the earlier of (i) five years from the First Issuance Date, or if the Second Issuance occurs, five years from the Second Issuance Date or (ii) a Change of Control (as defined in the articles supplementary) at a per share conversion rate equal to the Liquidation Preference divided by the then Common Stock Fair Market Value (as defined in the articles supplementary).

Related Party Transactions

Related Party Transactions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Related Party Transactions	Related Party Transactions Summarized below are the related party costs incurred by the Company for the nine months ended September 30, 2018 , and 2017 , respectively, and amounts payable as of September 30, 2018 and December 31, 2017 : Incurred for the Nine Months Ended September 30, Payable as of September 30, Payable as of December 31, 2018 2017 2018 2017 Expensed Corporate operating expenses $ 2,168 $ 1,677 $ 806 $ 658 Asset management fees (1) — 8,027 — — Property management fees 1,365 1,347 153 158 Performance distribution allocation 6,200 213 6,224 2,394 Advisory fees 6,970 273 784 762 Capitalized/Offering Acquisition fees and (2) — 1,099 — — Organization and offering expense 1,113 250 1,305 (6) 192 Other costs advanced by the Advisor 938 604 319 285 Selling commissions (3) 66 1,127 — — Dealer Manager fees 11 393 — — Stockholder servicing fee (4) 175 565 9,353 12,377 Advisor advances: (5) Organization and offering 45 136 44 8 Dealer Manager fees — 791 — 62 Total $ 19,051 $ 16,502 $ 18,988 $ 16,896 (1) As part of the Follow-On Offering, the Company's new management compensation structure no longer includes asset management fees. (2) Effective September 20, 2017, the Advisor is not entitled to acquisition fees, disposition fees or financing fees; provided, however, that the Advisor will receive the compensation set forth in the original advisory agreement for the Company’s investment in an approximately 1,000,000 square foot property located at 39000 Amrheim Road, Livonia, Michigan 48150 with a total transaction price of approximately $80.0 million . (3) On September 18, 2017, the Company and the Dealer Manager entered into a dealer manager agreement for the Follow-On Offering. See the "Dealer Manager Agreement" section below for details regarding selling commissions and dealer manager fees. (4) The Dealer Manager continues to receive a stockholder servicing fee with respect to Class AA shares as detailed in the Company's IPO prospectus. The stockholder servicing fee is paid quarterly and accrues daily in an amount equal to 1/365th of 1.0% of the NAV per share of the Class AA shares, up to an aggregate of 4% of the gross proceeds of Class AA shares sold. The Company will cease paying the stockholder servicing fee with respect to the Class AA shares at the earlier of (i) the date at which the aggregate underwriting compensation from all sources equals 10% of the gross proceeds from the sale of shares in Company's IPO (excluding proceeds from sales pursuant to the related DRP); (ii) the fourth anniversary of the last day of the fiscal quarter in which the Company's IPO terminated; (iii) the date that such Class AA share is redeemed or is no longer outstanding; and (iv) the occurrence of a merger, listing on a national securities exchange, or an extraordinary transaction. (5) Pursuant to the original advisory agreement, commencing November 2, 2015, the Company remained obligated to reimburse the Advisor for organizational and offering costs incurred after such date. Terms of the organizational and offering costs are included in the Company's 2016 Annual Report on Form 10-K filed on March 15, 2017. (6) Excludes amounts in excess of the 15% organization and offering costs limitation. See Note 8, Equity , for additional details. On September 20, 2017, an affiliated entity of the Sponsor purchased 263,992 New Shares for $2.5 million . As of September 30, 2018 , the total outstanding shares owned by affiliates (including DRP) was 563,440 . Advisory Agreement In connection with the Follow-On Offering, on September 20, 2017, the Company entered into the Advisory Agreement with the Advisor and the Operating Partnership. The Advisory Agreement is substantially similar to the Original Advisory Agreement, except that the Company will not pay the Advisor any acquisition, financing or other similar fees from proceeds raised in the Follow-On Offering in connection with making investments and will instead pay the Advisor an advisory fee that will be payable in arrears on a monthly basis and accrues daily in an amount equal to 1/365th of 1.25% of the NAV for each class of common stock for each day. Performance Distribution Allocation So long as the Advisory Agreement has not been terminated (including by means of non-renewal), the Advisor will hold a special limited partner interest in the Operating Partnership that entitles it to receive a distribution from the Operating Partnership equal to 12.5% of the total return, subject to a 5.5% hurdle amount and a high water mark, with a catch-up (terms of the performance distribution allocation are included in the Company's 2017 Annual Report on Form 10-K filed on March 9, 2018). Such distribution will be made annually and accrue daily. On February 16, 2018, the Company paid in cash approximately $1.2 million and issued approximately $1.2 million in Class I limited partnership units to the Advisor. The Advisor elected to receive 50% in cash and the remaining in Class I limited partnership units. Operating Expenses The Advisor and its affiliates are entitled to reimbursement for certain expenses incurred on behalf of the Company in connection with providing administrative services, including related personnel costs; provided, however, the Advisor must reimburse the Company for the amount, if any, by which total operating expenses (as defined), including advisory fees, paid during the previous 12 months then ended exceeded the greater of: (i) 2% of the Company’s average invested assets for that 12 months then ended; or (ii) 25% of the Company’s net income, before any additions to reserves for depreciation, bad debts or other expenses connected with the acquisition and disposition of real estate interests and before any gain from the sale of the Company’s assets, for that fiscal year, unless the Company’s board of directors has determined that such excess expenses were justified based on unusual and non-recurring factors. The Advisor may waive or defer all or a portion of these reimbursements or elect to receive Class I shares or Class I units of the Operating Partnership in lieu of these reimbursements at any time and from time to time, in its sole discretion. For the nine months ended September 30, 2018 and 2017 , the Company’s total operating expenses did not exceed the 2%/25% guideline. The Company reimbursed the Advisor and its affiliates a portion of the compensation paid by the Advisor and its affiliates for the Company's principal financial officer, Javier F. Bitar, executive vice president, David C. Rupert, and vice president and secretary, Howard S. Hirsch of approximately $0.6 million and $0.5 million , which is partially included in offering costs with the remaining amount included in corporate operating expenses to affiliates for the nine months ended September 30, 2018 and 2017 , respectively, for services provided to the Company, for which the Company does not pay the Advisor a fee. In addition, the Company incurred approximately $0.07 million and $0.1 million in reimbursable expenses to the Advisor for services provided to the Company by certain of its other executive officers for each of the nine months ended September 30, 2018 and 2017 , respectively. The reimbursable expenses include components of salaries, bonuses, benefits and other overhead charges and are based on the percentage of time each executive officer spends on the Company's affairs. Dealer Manager Agreement The Company entered into a dealer manager agreement (the "Dealer Manager Agreement") and associated form of participating dealer agreement with the Dealer Manager. The terms of the Dealer Manager Agreement are substantially similar to the terms of the dealer manager agreement from the Company's IPO, except as it relates to the share classes offered and the fees to be received by the Dealer Manager (terms of the Dealer Manager Agreement are included in the Company's 2017 Annual Report on Form 10-K filed on March 9, 2018). Distribution Fees Subject to Financial Industry Regulatory Authority, Inc.'s limitations on underwriting compensation, under the Dealer Manager Agreement the Company will pay the Dealer Manager a distribution fee for ongoing services rendered to stockholders by participating broker-dealers or broker-dealers servicing investors’ accounts, referred to as servicing broker-dealers. The fee accrues daily and is paid monthly in arrears and is calculated based on the average daily NAV for the applicable month (the “Average NAV”). The distribution fees for the different share classes are as follows: (i) with respect to the outstanding Class T shares equal to 1/365th of 1.0% of the Average NAV of the outstanding Class T shares for each day, consisting of an advisor distribution fee of 1/365th of 0.75% and a dealer distribution fee of 1/365th of 0.25% of the Average NAV of the Class T shares for each day; (ii) with respect to the outstanding Class S shares equal to 1/365th of 1.0% of the Average NAV of the outstanding Class S shares for each day; and (iii) with respect to the outstanding Class D shares equal to 1/365th of 0.25% of the Average NAV of the outstanding Class D shares for each day. The Company will not pay a distribution fee with respect to the outstanding Class I shares. The distribution fees will accrue daily and be paid monthly in arrears. The Dealer Manager will reallow the distribution fees to participating broker-dealers and servicing broker-dealers for ongoing services performed by such broker-dealers, and will retain any such distribution fees to the extent a broker-dealer is not eligible to receive them for failure to provide such services. The Dealer Manager will waive the distribution fees for any purchases by affiliates of the Company. The Company will cease paying the distribution fee with respect to any Class T share, Class S share or Class D share held in a stockholder's account at the end of the month in which the Dealer Manager in conjunction with the transfer agent determines that total selling commissions, dealer manager fees and distribution fees paid with respect to all shares from the Follow-On Offering held by such stockholder within such account would exceed, in the aggregate, 9.0% (or a lower limit as set forth in any applicable agreement between the Dealer Manager and a participating broker-dealer) of the gross proceeds from the sale of such shares (including the gross proceeds of any shares issued under the DRP with respect thereto). At the end of such month, such Class T share, Class S share or Class D share (and any shares issued under the DRP with respect thereto) will convert into a number of Class I shares (including any fractional shares) with an equivalent NAV as such share. In addition, the Company will cease paying the distribution fee on the Class T shares, Class S shares and Class D shares on the earlier to occur of the following: (i) a listing of the Company's shares, (ii) a merger or consolidation with or into another entity, or the sale or other disposition of all or substantially all of the Company's assets, including any liquidation of the Company or (iii) the date following the completion of the primary portion of the Follow-On Offering on which, in the aggregate, underwriting compensation from all sources in connection with the Follow-On Offering, including selling commissions, dealer manager fees, the distribution fee and other underwriting compensation, is equal to 9% of the gross proceeds from the Company's primary offering. Conflicts of Interest The Sponsor, Advisor, Property Manager and their officers and certain of their key personnel and their respective affiliates currently serve as key personnel, advisors, managers and sponsors or co-sponsors to some or all of 12 other programs affiliated with the Sponsor, including Griffin Capital Essential Asset REIT, Inc. ("GCEAR"), Griffin-American Healthcare REIT III, Inc. ("GAHR III"), Griffin-American Healthcare REIT IV, Inc. ("GAHR IV") and Phillips Edison Grocery Center REIT III, Inc. ("PECO III"), all of which are publicly-registered, non-traded real estate investment trusts, and Griffin Institutional Access Real Estate Fund ("GIA Real Estate Fund") and Griffin Institutional Access Credit Fund ("GIA Credit Fund"), both of which are non-diversified, closed-end management investment companies that are operated as interval funds under the Investment Company Act of 1940, as amended (the "1940 Act"). Because these persons have competing demands on their time and resources, they may have conflicts of interest in allocating their time between the Company’s business and these other activities. Some of the material conflicts that the Advisor, the Dealer Manager or its affiliates will face are (1) competing demand for time of the Advisor’s executive officers and other key personnel from the Sponsor and other affiliated entities; (2) determining if certain investment opportunities should be recommended to the Company or another program sponsored or co-sponsored by the Sponsor; and (3) influence of the fee structure under the Advisory Agreement and distribution structure of the operating partnership agreement that could result in actions not necessarily in the long-term best interest of the Company's stockholders. The board of directors has adopted the Sponsor’s acquisition allocation policy as to the allocation of acquisition opportunities among the Company and GCEAR, which is as follows: The Sponsor will allocate potential investment opportunities to the Company and GCEAR based on the following factors: • the investment objectives of each program; • the amount of funds available to each program; • the financial impact of the acquisition on each program, including each program’s earnings and distribution ratios; • various strategic considerations that may impact the value of the investment to each program; • the effect of the acquisition on concentration/diversification of each program’s investments; and • the income tax effects of the purchase to each program. In the event all acquisition allocation factors have been exhausted and an investment opportunity remains equally suitable for the Company and GCEAR, the Sponsor will offer the investment opportunity to the REIT that has had the longest period of time elapse since it was offered an investment opportunity. If the Sponsor no longer sponsors GCEAR, then, in the event that an investment opportunity becomes available that is suitable, under all of the factors considered by the Advisor, for both the Company and one or more other entities affiliated with the Sponsor, the Sponsor has agreed to present such investment opportunities to the Company first, prior to presenting such opportunities to any other programs sponsored by or affiliated with the Sponsor. In determining whether or not an investment opportunity is suitable for more than one program, the Advisor, subject to approval by the board of directors, shall examine, among others, the following factors: • anticipated cash flow of the property to be acquired and the cash requirements of each program; • effect of the acquisition on diversification of each program’s investments; • policy of each program relating to leverage of properties; • income tax effects of the purchase to each program; • size of the investment; • no significant increase in the cost of financing; and • amount of funds available to each program and the length of time such funds have been available for investment. Economic Dependency The Company will be dependent on the Advisor and the Dealer Manager for certain services that are essential to the Company, including the sale of the Company's shares of common stock available for issue, the identification, evaluation, negotiation, purchase and disposition of properties and other investments, management of the daily operations of the Company’s real estate portfolio, and other general and administrative responsibilities. In the event that these companies are unable to provide the respective services, the Company will be required to obtain such services from other resources.	Related Party Transactions Summarized below are the related-party costs incurred by the Company for the years ended December 31, 2017 , 2016 and 2015 , respectively, and any related amounts payable as of December 31, 2017 and 2016 : Incurred as of December 31, Payable as of December 31, 2017 2016 2015 2017 2016 Expensed Acquisition fees and expenses $ — $ 6,324 $ 11,438 $ — $ — Operating expenses 2,336 1,622 1,911 658 18 Asset management fees 8,027 6,413 2,624 — 807 Property management fees 1,799 1,052 333 158 143 Performance distributions 2,394 — — 2,394 — Advisory Fees 2,550 — — 762 — Capitalized/Offering Acquisition fees and expenses (1) 1,099 7,606 — — — Organization and offering expense 192 — 3,150 192 — Other costs advanced by the Advisor 662 304 2,598 285 12 Preferred offering costs (2) — — 375 — — Selling commissions (3) 1,128 11,397 16,303 — 54 Dealer Manager fees (4) 393 3,949 7,303 — 18 Stockholder servicing fee 660 17,449 25 12,377 16,020 Advisor Advances: (5) Organization and offering expenses 179 2,634 382 8 2,477 Dealer Manager fees 853 8,069 765 62 2,932 Total $ 22,272 $ 66,819 $ 47,207 $ 16,896 $ 22,481 (1) Effective September 20, 2017, the Advisor is not entitled to acquisition fees, disposition fees or financing fees; provided, however, that the Advisor will receive the compensation set forth in the Original Advisory Agreement for the Company’s investment in an approximately 1,000,000 square foot property located at 39000 Amrheim Road, Livonia, Michigan 48150 with a total transaction price of approximately $80 million . (2) The Company recognized a redemption premium on preferred units issued to an affiliate of approximately $0.4 million , which represented a write-off of original issuance costs. (3) On September 18, 2017, the Company and the Dealer Manager entered into a dealer manager agreement for the follow-on offering. See the “Dealer Manager Agreement” section below for details regarding selling commissions and dealer manager fees. (4) The Dealer Manager continues to receive a stockholder servicing fee with respect to Class AA shares as detailed in the Company’s IPO prospectus. The stockholder servicing fee is paid quarterly and accrues daily in an amount equal to 1/365th of 1% of the NAV per share of the Class AA shares, up to an aggregate of 4% of the gross proceeds of Class AA shares sold. The Company will cease paying the stockholder servicing fee with respect to the Class AA shares at the earlier of (i) the date at which the aggregate underwriting compensation from all sources equals 10% of the gross proceeds from the sale of shares in the Company’s IPO (excluding proceeds from sales pursuant to the related DRP); (ii) the fourth anniversary of the last day of the fiscal quarter in which the Company’s IPO terminated; (iii) the date that such Class AA share is redeemed or is no longer outstanding; and (iv) the occurrence of a merger, listing on a national securities exchange, or an extraordinary transaction. (5) Pursuant to the Original Advisory Agreement, commencing November 2, 2015, the Company remained obligated to reimburse the Advisor for organizational and offering costs incurred after such date. Terms of the organizational and offering costs are included in the Company’s 2016 Annual Report on Form 10-K filed on March 15, 2017. Advisory Agreement In connection with the follow-on offering, on September 20, 2017, the Company entered into the Advisory Agreement with the Advisor and the Operating Partnership. The Advisory Agreement is substantially similar to the Original Advisory Agreement, except that the Company will not pay the Advisor any acquisition, financing or other similar fees from proceeds raised in the follow-on offering in connection with making investments and will instead pay the Advisor an advisory fee that will be payable in arrears on a monthly basis and accrues daily in an amount equal to 1/365th of 1.25% of the NAV for each class of common stock for each day. Performance Distribution So long as the Advisory Agreement has not been terminated (including by means of non-renewal), the Advisor will hold a special limited partner interest in the Operating Partnership that entitles it to receive a distribution from the Operating Partnership equal to 12.5% of the Total Return, subject to a 5.5% Hurdle Amount and a High Water Mark, with a Catch-Up (each term as defined below). Such distribution will be made annually and accrue daily. Specifically, the Advisor will be entitled to a performance distribution in an amount equal to: - First, if the Total Return for the applicable period exceeds the sum of (i) the Hurdle Amount for that period and (ii) the Loss Carryforward Amount (any such excess, “Excess Profits”), 100% of such annual Excess Profits until the total amount distributed to the Advisor equals 12.5% of the sum of (x) the Hurdle Amount for that period and (y) any amount distributed to the Advisor pursuant to this clause (this is commonly referred to as a “Catch-Up”); and - Second, to the extent there are remaining Excess Profits, 12.5% of such remaining Excess Profits. “Total Return” for any period since the end of the prior calendar year shall equal the sum of: (i) all distributions accrued or paid (without duplication) on the Operating Partnership units outstanding at the end of such period since the beginning of the then current calendar year plus (ii) the change in aggregate NAV of such units since the beginning of the year, before giving effect to (x) changes resulting solely from the proceeds of issuances of Operating Partnership units, (y) any allocation/accrual of the performance distribution and (z) applicable distribution fee and stockholder servicing fee expenses (including any payments made to us for payment of such expenses). For the avoidance of doubt, the calculation of the Total Return will (i) include any appreciation or depreciation in the NAV of units issued during the then current calendar year but (ii) exclude the proceeds from the initial issuance of such units. “Hurdle Amount” for any period during a calendar year means that amount that results in a 5.5% annualized internal rate of return on the NAV of the Operating Partnership units outstanding at the beginning of the then current calendar year and all Operating Partnership units issued since the beginning of the then current calendar year, taking into account the timing and amount of all distributions accrued or paid (without duplication) on all such units and all issuances of the Operating Partnership units over the period and calculated in accordance with recognized industry practices. The ending NAV of the Operating Partnership units used in calculating the internal rate of return will be calculated before giving effect to any allocation/accrual of the performance distribution and applicable distribution fee and stockholder servicing fee expenses. For the avoidance of doubt, the calculation of the Hurdle Amount for any period will exclude any Operating Partnership units redeemed during such period, which units will be subject to the performance distribution upon redemption as described below. Except as described in the Loss Carryforward Amount below, any amount by which the Total Return falls below the Hurdle Amount will not be carried forward to subsequent periods. “Loss Carryforward Amount” shall initially equal zero and shall cumulatively increase by the absolute value of any negative annual Total Return and decrease by any positive annual Total Return, provided that the Loss Carryforward Amount shall at no time be less than zero and provided further that the calculation of the Loss Carryforward Amount will exclude the Total Return related to any Operating Partnership units redeemed during such year, which units will be subject to the performance distribution upon redemption as described below. The effect of the Loss Carryforward Amount is that the recoupment of past annual Total Return losses will offset the positive annual Total Return for purposes of the calculation of the Advisor’s performance distribution. This is referred to as a “High Water Mark.” The Advisor will also be allocated a performance distribution with respect to all Operating Partnership units that are redeemed at the end of any quarter (in connection with redemptions of the Company’s shares in the share redemption programs) in an amount calculated as described above with the relevant period being the portion of the year for which such unit was outstanding, and proceeds for any such unit redemption will be reduced by the amount of any such performance distribution. Distributions on the performance distribution may be paid in cash or Class I units of the Operating Partnership, at the election of the Advisor. In 2017, the performance distribution was prorated for the portion of the calendar year that the follow-on offering was effective. Operating Expenses The Advisor and its affiliates are entitled to reimbursement for certain expenses incurred on behalf of the Company in connection with providing administrative services, including related personnel costs; provided, however, the Advisor must reimburse the Company for the amount, if any, by which total operating expenses (as defined), including advisory fees, paid during the previous 12 months then ended exceeded the greater of: (i) 2% of the Company’s average invested assets for that 12 months then ended; or (ii) 25% of the Company’s net income, before any additions to reserves for depreciation, bad debts or other expenses connected with the acquisition and disposition of real estate interests and before any gain from the sale of the Company’s assets, for that fiscal year, unless the Company’s board of directors has determined that such excess expenses were justified based on unusual and non-recurring factors. The Advisor may waive or defer all or a portion of these reimbursements or elect to receive Class I shares or Class I units of the Operating Partnership in lieu of these reimbursements at any time and from time to time, in its sole discretion. For the years ended December 31, 2017 and 2016 , the Company’s total operating expenses did not exceed the 2%/25% guideline. The Company reimbursed the Advisor and its affiliates a portion of the compensation paid by the Advisor and its affiliates for the Company’s principal financial officer, Javier F. Bitar, executive vice president, David C. Rupert, and vice president and secretary, Howard S. Hirsch of approximately $0.7 million and $0.5 million , which is included in offering costs for the years ended December 31, 2017 and 2016 , for services provided to the Company, for which the Company does not pay the Advisor a fee. In addition, the Company incurred approximately $0.2 million in reimbursable expenses to the Advisor for services provided to the Company by certain of its other executive officers for each of the years ended December 31, 2017 and 2016 . The reimbursable expenses include components of salaries, bonuses, benefits and other overhead charges and are based on the percentage of time each executive officer spends on the Company’s affairs. Dealer Manager Agreement The Company entered into a dealer manager agreement and associated form of participating dealer agreement (the “Dealer Manager Agreement”) with the Dealer Manager. The terms of the Dealer Manager Agreement are substantially similar to the terms of the dealer manager agreement from the Company’s IPO, except as it relates to the share classes offered and the fees to be received by the Dealer Manager (terms of the previous dealer manager agreement are included in the Company’s 2016 Annual Report on Form 10-K filed on March 15, 2017). Pursuant to the Dealer Manager Agreement, the Company will pay to the Dealer Manager selling commissions of up to 3.0% of the total purchase price for each sale of Class T shares and selling commissions of up to 3.5% of the total purchase price for each sale of Class S shares. The Company will not pay to the Dealer Manager any selling commissions in respect of the purchase of any Class D shares, Class I shares or DRP shares. The Company also will pay to the Dealer Manager dealer manager fees of up to 0.5% of the total purchase price for each sale of Class T shares. The Company will not pay to the Dealer Manager any dealer manager fees in respect of the purchase of any Class S shares, Class D shares, Class I shares or DRP shares. Substantially all of the selling commissions and dealer manager fees may be reallowed by the Dealer Manager to the participating broker-dealers who sold the shares giving rise to such selling commissions and dealer manager fees. Distribution Fees Subject to Financial Industry Regulatory Authority, Inc.’s limitations on underwriting compensation, under the Dealer Manager Agreement the Company will pay the Dealer Manager a distribution fee for ongoing services rendered to stockholders by participating broker-dealers or broker-dealers servicing investors’ accounts, referred to as servicing broker-dealers. The fee accrues daily and is paid monthly in arrears and is calculated based on the average daily NAV for the applicable month (the “Average NAV”). The distribution fees for the different share classes are as follows: (i) with respect to the outstanding Class T shares equal to 1/365th of 1.0% of the Average NAV of the outstanding Class T shares for each day, consisting of an advisor distribution fee of 1/365th of 0.75% and a dealer distribution fee of 1/365th of 0.25% of the Average NAV of the Class T shares for each day; (ii) with respect to the outstanding Class S shares equal to 1/365th of 1.0% of the Average NAV of the outstanding Class S shares for each day; and (iii) with respect to the outstanding Class D shares equal to 1/365th of 0.25% of the Average NAV of the outstanding Class D shares for each day. The Company will not pay a distribution fee with respect to the outstanding Class I shares. The distribution fees will accrue daily and be paid monthly in arrears. The Dealer Manager will reallow the distribution fees to participating broker-dealers and servicing broker-dealers for ongoing services performed by such broker-dealers, and will retain any such distribution fees to the extent a broker-dealer is not eligible to receive them for failure to provide such services. The Dealer Manager will waive the distribution fees for any purchases by affiliates of the Company. The Company will cease paying the distribution fee with respect to any Class T share, Class S share or Class D share held in a stockholder’s account at the end of the month in which the Dealer Manager in conjunction with the transfer agent determines that total selling commissions, dealer manager fees and distribution fees paid with respect to all shares from the follow-on offering held by such stockholder within such account would exceed, in the aggregate, 9.0% (or a lower limit as set forth in any applicable agreement between the Dealer Manager and a participating broker-dealer) of the gross proceeds from the sale of such shares (including the gross proceeds of any shares issued under the DRP with respect thereto). At the end of such month, such Class T share, Class S share or Class D share (and any shares issued under the DRP with respect thereto) will convert into a number of Class I shares (including any fractional shares) with an equivalent NAV as such share. In addition, the Company will cease paying the distribution fee on the Class T shares, Class S shares and Class D shares on the earlier to occur of the following: (i) a listing of the Company’s shares, (ii) a merger or consolidation with or into another entity, or the sale or other disposition of all or substantially all of the Company’s assets, including any liquidation of the Company or (iii) the date following the completion of the primary portion of the follow-on offering on which, in the aggregate, underwriting compensation from all sources in connection with the follow-on offering, including selling commissions, dealer manager fees, the distribution fee and other underwriting compensation, is equal to 9.0% of the gross proceeds from the Company’s primary offering. Property Management Agreement In the event that the Company contracts directly with non-affiliated third party property managers with respect to its individual properties, the Company pays the Property Manager an oversight fee equal to 1.0% of the gross revenues of the property managed, plus reimbursable costs as applicable. Reimbursable costs and expenses include wages and salaries and other expenses of employees engaged in operating, managing and maintaining the Company’s properties, as well as certain allocations of office, administrative, and supply costs. The Property Manager may waive or defer all or a portion of these reimbursements or elect to receive Class I shares or Class I units of the Operating Partnership in lieu of these reimbursements at any time and from time to time, in its sole discretion. In the event that the Company contracts directly with the Property Manager with respect to a particular property, the Company pays the Property Manager aggregate property management fees of up to 3.0% , or greater if the lease so allows, of gross revenues received for management of the Company’s properties, plus reimbursable costs as applicable. These property management fees may be paid or re-allowed to third party property managers if the Property Manager contracts with a third party. In no event will the Company pay both a property management fee to the Property Manager and an oversight fee to the Property Manager with respect to a particular property. In addition, the Company may pay the Property Manager or its designees a leasing fee in an amount equal to the fee customarily charged by others rendering similar services in the same geographic area. The Company may also pay the Property Manager or its designees a construction management fee for planning and coordinating the construction of any tenant directed improvements for which the Company is responsible to perform pursuant to lease concessions, including tenant-paid finish-out or improvements. The Property Manager shall also be entitled to a construction management fee of 5.0% of the cost of improvements. In the event that the Property Manager assists with the development or redevelopment of a property, the Company may pay a separate market-based fee for such services. Conflicts of Interest The Sponsor, Advisor, Property Manager and their officers and certain of their key personnel and their respective affiliates currently serve as key personnel, advisors, managers and sponsors or co-sponsors to some or all of 12 other programs affiliated with the Sponsor, including Griffin Capital Essential Asset REIT, Inc. (“GCEAR”), Griffin-American Healthcare REIT III, Inc. (“GAHR III”), and Griffin-American Healthcare REIT IV, Inc. (“GAHR IV”), all of which are publicly-registered, non-traded real estate investment trusts, and Griffin Institutional Access Real Estate Fund (“GIA Real Estate Fund”) and Griffin Institutional Access Credit Fund (“GIA Credit Fund”), both of which are non-diversified, closed-end management investment companies that are operated as interval funds under the Investment Company Act of 1940, as amended (the “1940 Act”). Because these persons have competing demands on their time and resources, they may have conflicts of interest in allocating their time between the Company’s business and these other activities. Some of the material conflicts that the Advisor, the Dealer Manager or its affiliates will face are (1) competing demand for time of the Advisor’s executive officers and other key personnel from the Sponsor and other affiliated entities; (2) determining if certain investment opportunities should be recommended to the Company or another program sponsored or co-sponsored by the Sponsor; and (3) influence of the fee structure under the Advisory Agreement and distribution structure of the operating partnership agreement that could result in actions not necessarily in the long-term best interest of the Company’s stockholders. The board of directors has adopted the Sponsor’s acquisition allocation policy as to the allocation of acquisition opportunities among GCEAR and the Company, which is as follows: The Sponsor will allocate potential investment opportunities to the Company and GCEAR based on the following factors: • the investment objectives of each program; • the amount of funds available to each program; • the financial impact of the acquisition on each program, including each program’s earnings and distribution ratios; • various strategic considerations that may impact the value of the investment to each program; • the effect of the acquisition on concentration/diversification of each program’s investments; and • the income tax effects of the purchase to each program. In the event all acquisition allocation factors have been exhausted and an investment opportunity remains equally suitable for the Company and GCEAR, the Sponsor will offer the investment opportunity to the REIT that has had the longest period of time elapse since it was offered an investment opportunity. If the Sponsor no longer sponsors GCEAR, then, in the event that an investment opportunity becomes available that is suitable, under all of the factors considered by the Advisor, for both the Company and one or more other entities affiliated with the Sponsor, the Sponsor has agreed to present such investment opportunities to the Company first, prior to presenting such opportunities to any other programs sponsored by or affiliated with the Sponsor. In determining whether or not an investment opportunity is suitable for more than one program, the Advisor, subject to approval by the board of directors, shall examine, among others, the following factors: • anticipated cash flow of the property to be acquired and the cash requirements of each program; • effect of the acquisition on diversification of each program’s investments; • policy of each program relating to leverage of properties; • income tax effects of the purchase to each program; • size of the investment; • no significant increase in the cost of financing; and • amount of funds available to each program and the length of time such funds have been available for investment. Economic Dependency The Company will be dependent on the Advisor and the Dealer Manager for certain services that are essential to the Company, including the sale of the Company’s shares of common stock available for issue, the identification, evaluation, negotiation, purchase and disposition of properties and other investments, management of the daily operations of the Company’s real estate portfolio, and other general and administrative responsibilities. In the event that these companies are unable to provide the respective services, the Company will be required to obtain such services from other resources.
Griffin Capital Essential Asset REIT, Inc. [Member]
Related Party Transaction [Line Items]
Related Party Transactions	Related Party Transactions Summarized below are the related party costs incurred by the Company for the nine months ended September 30, 2018 and 2017 , respectively, and any related amounts payable as of September 30, 2018 and December 31, 2017 : Incurred for the Nine Months Payable as of Ended September 30, September 30, December 31, 2018 2017 2018 2017 Expensed Operating expenses $ 2,630 $ 1,983 $ 949 $ 670 Asset management fees 17,628 17,744 1,999 1,873 Property management fees 6,992 7,466 746 725 Costs advanced by the Advisor 396 419 324 267 Capitalized Acquisition fees (1) 5,331 — — — Leasing commissions — 1,752 — — Total, net of real estate assets held for sale $ 32,977 $ 29,364 $ 4,018 $ 3,535 Asset management fees related to real estate held for sale 42 42 5 5 Property management fees related to real estate held for sale 57 53 — 5 Total $ 33,076 $ 29,459 $ 4,023 $ 3,545 (1) Acquisition fees related to the acquisitions of Quaker, McKesson, and Shaw were capitalized as the acquisition did not meet the business combination criteria. Advisory Agreement The Company currently does not have nor does it expect to have any employees. The Advisor will be primarily responsible for managing the business affairs and carrying out the directives of the Company’s board of directors. The Company entered into an advisory agreement with the Advisor. The Advisory Agreement entitles the Advisor to specified fees and expense reimbursements upon the provision of certain services with regard to the Public Offerings and investment of funds in real estate properties, among other services, including as reimbursement for organizational and offering costs incurred by the Advisor on the Company’s behalf and reimbursement of certain costs and expenses incurred by the Advisor in providing services to the Company. Management Compensation The following table summarizes the compensation and fees the Company has paid or may pay to the Advisor, the Property Manager, and the Sponsor and other affiliates, including amounts to reimburse costs for providing services. Type of Compensation (Recipient) Determination of Amount Acquisition Fees and Expenses (Advisor) Under the Advisory Agreement, the Advisor receives acquisition fees equal to 2.5%, and reimbursement for actual acquisition related expenses incurred by the Advisor of up to 0.50% of the contract purchase price, as defined therein, of each property acquired by the Company, and reimbursement for actual acquisition expenses incurred on the Company's behalf, including certain payroll costs for acquisition-related efforts by the Advisor's personnel, as defined in the agreement. In addition, the Company pays acquisition expenses to unaffiliated third parties equal to approximately 0.60% of the purchase price of the Company's properties. The acquisition fee and acquisition expenses paid by the Company shall be reasonable and in no event exceed an amount equal to 6% of the contract purchase price, unless approved by a majority of the independent directors. Disposition Fee (Advisor) In the event that the Company sells any or all of its properties (or a portion thereof), or all or substantially all of the business or securities of the Company are transferred or otherwise disposed of by way of a merger or other similar transaction, the Advisor will be entitled to receive a disposition fee if the Advisor or an affiliate provides a substantial amount of the services (as determined by a majority of the Company's directors, including a majority of the independent directors) in connection with such transaction. The disposition fee the Advisor or such affiliate shall be entitled to receive at closing will be equal to the lesser of: (1) 3% of the Contract Sales Price, as defined in the Advisory Agreement or (2) 50% of the Competitive Commission, as defined in the Advisory Agreement; provided, however, that in connection with certain types of transactions described further in the Advisory Agreement, the disposition fee shall be subordinated to Invested Capital (as defined in the operating partnership agreement). The disposition fee may be paid in addition to real estate commissions or other commissions paid to non-affiliates, provided that the total real estate commissions or other commissions (including the disposition fee) paid to all persons by the Company or the operating partnership shall not exceed an amount equal to the lesser of (i) 6% of the aggregate Contract Sales Price or (ii) the Competitive Commission. Asset Management Fee (Advisor) The Advisor receives an annual asset management fee for managing the Company’s assets equal to 0.75% of the Average Invested Assets, defined as the aggregate carrying value of the assets invested before reserves for depreciation. The fee will be computed based on the average of these values at the end of each month. The asset management fees are earned monthly. Operating Expenses (Advisor) The Advisor and its affiliates are entitled to reimbursement, at cost, for actual expenses incurred by them on behalf of the Company in connection with their provision of administrative services, including related personnel costs; provided, however, the Advisor must reimburse the Company for the amount, if any, by which total operating expenses, including advisory fees, paid during the previous 12 months then ended exceeded the greater of: (i) 2% of the Company’s average invested assets for that 12 months then ended; or (ii) 25% of the Company’s net income, before any additions to reserves for depreciation, bad debts or other expenses connected with the acquisition and disposition of real estate interests and before any gain from the sale of the Company’s assets, for that fiscal year, unless the Company’s board of directors has determined that such excess expenses were justified based on unusual and non-recurring factors. For the nine months ended September 30, 2018 and 2017, the Company’s total operating expenses did not exceed the 2 %/25% guideline. Operating expenses for the nine months ended September 30, 2018 included approximately $0.4 million, to reimburse the Advisor and its affiliates a portion of the compensation paid by the Advisor and its affiliates for the Company's principal financial officer, Javier F. Bitar, executive vice president, David C. Rupert, and vice president and assistant secretary, Howard S. Hirsch, for services provided to the Company, for which the Company does not pay the Advisor a fee. In addition, the Company incurred approximately $0.2 million and $0.1 million for reimbursable expenses to the Advisor for services provided to the Company by certain of its other executive officers for the nine months ended September 30, 2018 and 2017, respectively. The reimbursable expenses include components of salaries, bonuses, benefits and other overhead charges and are based on the percentage of time each such executive officer spends on the Company's affairs. Property Management Fees (Property Manager) The Property Manager is entitled to receive a fee for its services in managing the Company’s properties up to 3% of the gross monthly revenues from the properties plus reimbursement of the costs of managing the properties. The Property Manager, in its sole and absolute discretion, can waive all or a part of any fee earned. In the event that the Property Manager assists with the development or redevelopment of a property, the Company may pay a separate market-based fee for such services. In the event that the Company contracts directly with a non-affiliated third-party property manager with respect to a particular property, the Company will pay the Property Manager an oversight fee equal to 1% of the gross revenues of the property managed. In no event will the Company pay both a property management fee to the Property Manager and an oversight fee to the Property Manager with respect to a particular property. In addition, the Company may pay the Property Manager or its designees a leasing fee in an amount equal to the fee customarily charged by others rendering similar services in the same geographic area. The Company may also pay the Property Manager or its designees a construction management fee for planning and coordinating the construction of any tenant directed improvements for which the Company is responsible to perform pursuant to lease concessions, including tenant-paid finish-out or improvements. The Property Manager shall also be entitled to a construction management fee of 5% of the cost of improvements. Subordinated Share of Net Sale Proceeds (Advisor) (1) Payable to the Advisor in cash upon the sale of a property after the Company's stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The share of net proceeds from the sale of property is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return. Subordinated Incentive Listing Distribution (Advisor) (1) Payable to the Advisor no earlier than 7 months and no later than 19 months following a listing of the shares on a national securities exchange, based upon the market value of the Company's shares during a period of 30 trading days commencing after the first day of the 6th month, but no later than the last day of the 18th month following a listing, the commencement date of which shall be chosen by the Advisor in its sole discretion, and after the Company's stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The distribution share is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return, and is payable in cash, shares of the Company's stock, units of limited partnership interest in the Operating Partnership, or a combination thereof. Subordinated Distribution Due Upon Termination (Advisor) Payable to the Advisor (in cash, shares of the Company's stock, units of limited partnership interest in the Operating Partnership, or a combination thereof), 1/3rd within 30 days of the date of involuntary termination of the Advisory Agreement, 1/3rd upon the one year anniversary of such date, and 1/3rd upon the two year anniversary of such date. Calculated based upon appraised value of properties less the fair value of the underlying debt, and plus or minus net current assets or net current liabilities, respectively, and payable after the Company's stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The distribution share is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return. Upon a voluntary termination of the Advisory Agreement, the Advisor will not be entitled to receive the Subordinated Distribution Due Upon Termination but instead will be entitled to receive at the time of the applicable liquidity event a distribution equal to the applicable Subordinated Share of Net Sale Proceeds, Subordinated Incentive Listing Distribution, or Subordinated Distribution Due Upon Extraordinary Transaction. Subordinated Distribution Due Upon Extraordinary Transaction (Advisor) (1) Payable to the Advisor upon the closing date of an Extraordinary Transaction (as defined in the operating partnership agreement); payable in cash, shares of the Company's stock, units of limited partnership in the Operating Partnership, or a combination thereof after the Company's stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The distribution share is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return. Sponsor Break-Even Amount (Sponsor) In the event of a merger of the Advisor into the Company or one of its affiliates in anticipation of listing or a merger with an already-listed entity, any merger consideration paid to the Company's sponsor or its affiliates in excess of unreturned and unreimbursed capital invested by the Company's sponsor and its affiliates into the Company, the Advisor, the Company's dealer manager, or affiliates, relating in any way to the business organization of the Company, the Operating Partnership, or any offering of the Company, shall be subordinated to the return of stockholders' invested capital. Such excess merger consideration shall be paid in stock that may not be traded for one year from the date of receipt, and such stock shall be held in escrow pending the occurrence of certain conditions outlined further in the Operating Partnership Agreement. (1) The Advisor cannot earn more than one incentive distribution. Any receipt by the Advisor of subordinated share of net sale proceeds (for anything other than a sale of the entire portfolio) will reduce the amount of the subordinated distribution due upon termination, the subordinated incentive listing distribution and the subordinated distribution due upon extraordinary transaction. Conflicts of Interest The Sponsor, Advisor, Property Manager and their officers and certain of their key personnel and their respective affiliates currently serve as key personnel, advisors, managers and sponsors or co-sponsors to some or all of 12 other programs affiliated with the Sponsor, including Griffin Capital Essential Asset REIT II, Inc. ("GCEAR II"), Griffin-American Healthcare REIT III, Inc. ("GAHR III"), Griffin-American Healthcare REIT IV, Inc. ("GAHR IV") and Phillips Edison Grocery Center REIT III ("PECO III"), each of which are publicly-registered, non-traded real estate investment trusts, and Griffin Institutional Access Real Estate Fund (“GIA Real Estate Fund”) and Griffin Institutional Access Credit Fund ("GIA Credit Fund"), both of which are non-diversified, closed-end management investment companies that are operated as interval funds under the Investment Company Act of 1940, as amended (the "1940 Act"). Because these persons have competing demands on their time and resources, they may have conflicts of interest in allocating their time between the Company’s business and these other activities. Some of the material conflicts that the Sponsor, Advisor, and Property Manager and their key personnel and their respective affiliates will face are (1) competing demand for time of the Advisor’s executive officers and other key personnel from the Sponsor and other affiliated entities; (2) determining if certain investment opportunities should be recommended to the Company or another program sponsored or co-sponsored by the Sponsor; and (3) influence of the fee structure under the Advisory Agreement and the distribution structure under the operating partnership agreement that could result in actions not necessarily in the long-term best interest of the Company’s stockholders. The board of directors has adopted the Sponsor’s acquisition allocation policy as to the allocation of acquisition opportunities among the Company and GCEAR II, which is based on the following factors: • the investment objectives of each program; • the amount of funds available to each program; • the financial impact of the acquisition on each program, including each program’s earnings and distribution ratios; • various strategic considerations that may impact the value of the investment to each program; • the effect of the acquisition on concentration/diversification of each program’s investments; and • the income tax effects of the purchase to each program. In the event all acquisition allocation factors have been exhausted and an investment opportunity remains equally suitable for the Company and GCEAR II, the Sponsor will offer the investment opportunity to the REIT that has had the longest period of time elapse since it was offered an investment opportunity. If the Sponsor no longer sponsors GCEAR II, then, in the event that an investment opportunity becomes available that is suitable, under all of the factors considered by the Advisor, for both the Company and one or more other entities affiliated with the Sponsor, the Sponsor has agreed to present such investment opportunities to the Company first, prior to presenting such opportunities to any other programs sponsored by or affiliated with the Sponsor. In determining whether or not an investment opportunity is suitable for more than one program, the Advisor, subject to approval by the board of directors, shall examine, among others, the following factors: • anticipated cash flow of the property to be acquired and the cash requirements of each program; • effect of the acquisition on diversification of each program’s investments; • policy of each program relating to leverage of properties; • income tax effects of the purchase to each program; • size of the investment; • no significant increase in the cost of financing; and • amount of funds available to each program and the length of time such funds have been available for investment. Economic Dependency The Company will be dependent on the Advisor for certain services that are essential to the Company, including the identification, evaluation, negotiation, purchase and disposition of properties and other investments, management of the daily operations of the Company’s real estate portfolio, and other general and administrative responsibilities. In the event that the Advisor is unable to provide the services, the Company will be required to obtain such services from other resources	Related Party Transactions Summarized below are the related-party costs incurred by the Company for the years ended December 31, 2017 , 2016 and 2015 , respectively, and any related amounts payable as of December 31, 2017 and 2016 : Incurred for the Year Ended December 31, Payable as of December 31, 2017 2016 2015 2017 2016 Expensed Acquisition fees and expenses $ — $ 1,322 $ 35,210 $ — $ — Operating expenses 2,652 1,525 1,608 670 — Asset management fees 23,499 23,530 19,389 1,878 1,982 Property management fees 9,782 9,740 7,622 730 737 Disposition fees (1) 1,950 — 640 — — Costs advanced by the Advisor 587 73 53 267 — Capitalized Acquisition fees (2) 3,791 — — — — Leasing commissions 1,752 — 2,105 — — Total $ 44,013 $ 36,190 $ 66,627 $ 3,545 $ 2,719 (1) Disposition fees with respect to real estate sold are included in the gain on sale of real estate in the accompanying consolidated statements of operations. (2) Acquisition fees related to the LPL acquisition were capitalized as the acquisition did not meet the business combination criteria (see Note 3, Real Estate, for additional details). Advisory Agreement The Company currently does not have nor does it expect to have any employees. The Advisor will be primarily responsible for managing the business affairs and carrying out the directives of the Company’s board of directors. The Company entered into an advisory agreement with the Advisor. The Advisory Agreement entitles the Advisor to specified fees and expense reimbursements upon the provision of certain services with regard to the Public Offerings and investment of funds in real estate properties, among other services, including reimbursement for organizational and offering costs incurred by the Advisor on the Company’s behalf and reimbursement of certain costs and expenses incurred by the Advisor in providing services to the Company. Management Compensation The following table summarizes the compensation and fees the Company has paid or may pay to the Advisor, the Property Manager, and the Sponsor and other affiliates, including amounts to reimburse costs for providing services: Type of Compensation (Recipient) Determination of Amount Acquisition Fees and Expenses (Advisor) Under the Advisory Agreement, the Advisor receives acquisition fees equal to 2.5%, and reimbursement for actual acquisition related expenses incurred by the Advisor of up to 0.50% of the contract purchase price, as defined therein, of each property acquired by the Company, and reimbursement for actual acquisition expenses incurred on the Company’s behalf, including certain payroll costs for acquisition-related efforts by the Advisor’s personnel, as defined in the agreement. In addition, the Company pays acquisition expenses to unaffiliated third parties equal to approximately 0.60% of the purchase price of the Company’s properties. The acquisition fee and acquisition expenses paid by the Company shall be reasonable and in no event exceed an amount equal to 6% of the contract purchase price, unless approved by a majority of the Company’s independent directors. Disposition Fee (Advisor) In the event that the Company sells any or all of its properties (or a portion thereof), or all or substantially all of the business or securities of the Company are transferred or otherwise disposed of by way of a merger or other similar transaction, the Advisor will be entitled to receive a disposition fee if the Advisor or an affiliate provides a substantial amount of the services (as determined by a majority of the Company’s directors, including a majority of the independent directors) in connection with such transaction. The disposition fee the Advisor or such affiliate shall be entitled to receive at closing will be equal to the lesser of: (1) 3% of the Contract Sales Price, as defined in the Advisory Agreement or (2) 50% of the Competitive Commission, as defined in the Advisory Agreement; provided, however, that in connection with certain types of transactions described further in the Advisory Agreement, the disposition fee shall be subordinated to Invested Capital (as defined in the operating partnership agreement). The disposition fee may be paid in addition to real estate commissions or other commissions paid to non-affiliates, provided that the total real estate commissions or other commissions (including the disposition fee) paid to all persons by the Company or the Operating Partnership shall not exceed an amount equal to the lesser of (i) 6% of the aggregate Contract Sales Price or (ii) the Competitive Commission. Asset Management Fee (Advisor) The Advisor receives an annual asset management fee for managing the Company’s assets equal to 0.75% of the Average Invested Assets, defined as the aggregate carrying value of the assets invested before reserves for depreciation. The fee will be computed based on the average of these values at the end of each month. The asset management fees are earned monthly. Operating Expenses (Advisor) The Advisor and its affiliates are entitled to reimbursement, at cost, for actual expenses incurred by them on behalf of the Company in connection with their provision of administrative services, including related personnel costs; provided, however, the Advisor must reimburse the Company for the amount, if any, by which total operating expenses, including advisory fees, paid during the previous 12 months then ended exceeded the greater of: (i) 2% of the Company’s average invested assets for that 12 months then ended; or (ii) 25% of the Company’s net income, before any additions to reserves for depreciation, bad debts or other expenses connected with the acquisition and disposition of real estate interests and before any gain from the sale of the Company’s assets, for that fiscal year, unless the Company’s board of directors has determined that such excess expenses were justified based on unusual and non-recurring factors. For the years ended December 31, 2017 and 2016, the Company’s total operating expenses did not exceed the 2 %/25 % guideline. Operating expenses for years ended December 31, 2017 and 2016 included approximately $0.6 million and $0.4 million, respectively, to reimburse the Advisor and its affiliates a portion of the compensation paid by the Advisor and its affiliates for the Company’s principal financial officer, Javier F. Bitar, executive vice president, David C. Rupert, and vice president and assistant secretary, Howard S. Hirsch, for services provided to the Company, for which the Company does not pay the Advisor a fee. In addition, the Company incurred approximately $0.2 million for reimbursable expenses to the Advisor for services provided to the Company by certain of its other executive officers for each of the years ended December 31, 2017 and 2016. The reimbursable expenses include components of salaries, bonuses, benefits and other overhead charges and are based on the percentage of time each such executive officer spends on the Company’s affairs. Property Management Fees (Property Manager) The Property Manager is entitled to receive a fee for its services in managing the Company’s properties up to 3% of the gross monthly revenues from the properties plus reimbursement of the costs of managing the properties. The Property Manager, in its sole and absolute discretion, can waive all or a part of any fee earned. In the event that the Property Manager assists with the development or redevelopment of a property, the Company may pay a separate market-based fee for such services. In the event that the Company contracts directly with a non-affiliated third-party property manager with respect to a particular property, the Company will pay the Property Manager an oversight fee equal to 1% of the gross revenues of the property managed. In no event will the Company pay both a property management fee to the Property Manager and an oversight fee to the Property Manager with respect to a particular property. In addition, the Company may pay the Property Manager or its designees a leasing fee in an amount equal to the fee customarily charged by others rendering similar services in the same geographic area. The Company may also pay the Property Manager or its designees a construction management fee for planning and coordinating the construction of any tenant directed improvements for which the Company is responsible to perform pursuant to lease concessions, including tenant-paid finish-out or improvements. The Property Manager shall also be entitled to a construction management fee of 5% of the cost of improvements. Subordinated Share of Net Sale Proceeds (Advisor) (1) Payable to the Advisor in cash upon the sale of a property after the Company’s stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The share of net proceeds from the sale of property is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return. Subordinated Incentive Listing Distribution (Advisor) (1) Payable to the Advisor no earlier than 7 months and no later than 19 months following a listing of the shares of common stock on a national securities exchange, based upon the market value of the Company’s shares of common stock during a period of 30 trading days commencing after the first day of the 6th month, but no later than the last day of the 18th month following a listing, the commencement date of which shall be chosen by the Advisor in its sole discretion, and after the Company’s stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The distribution share is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return, and is payable in cash, shares of the Company’s stock, units of limited partnership interest in the Operating Partnership, or a combination thereof. Subordinated Distribution Due Upon Termination (Advisor) Payable to the Advisor (in cash, shares of the Company’s stock, units of limited partnership interest in the Operating Partnership, or a combination thereof), 1/3rd within 30 days of the date of involuntary termination of the Advisory Agreement, 1/3rd upon the one year anniversary of such date, and 1/3rd upon the two year anniversary of such date. Calculated based upon appraised value of properties less the fair value of the underlying debt, and plus or minus net current assets or net current liabilities, respectively, and payable after the Company’s stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The distribution share is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return. Upon a voluntary termination of the Advisory Agreement, the Advisor will not be entitled to receive the Subordinated Distribution Due Upon Termination but instead will be entitled to receive at the time of the applicable liquidity event a distribution equal to the applicable Subordinated Share of Net Sale Proceeds, Subordinated Incentive Listing Distribution, or Subordinated Distribution Due Upon Extraordinary Transaction. Subordinated Distribution Due Upon Extraordinary Transaction (Advisor) (1) Payable to the Advisor upon the closing date of an Extraordinary Transaction (as defined in the operating partnership agreement); payable in cash, shares of the Company’s stock, units of limited partnership in the Operating Partnership, or a combination thereof after the Company’s stockholders receive a return of capital plus a 6% cumulative, non-compounded return. The distribution share is 5% if stockholders are paid a return of capital plus 6% to 8% annual cumulative non-compounding return, 10% if stockholders are paid a return of capital plus 8% to 10% annual cumulative non-compounding return, or 15% if stockholders are paid a return of capital plus 10% or more annual cumulative non-compounding return. Sponsor Break-Even Amount (Sponsor) In the event of a merger of the Advisor into the Company or one of its affiliates in anticipation of listing or a merger with an already-listed entity, any merger consideration paid to the Company’s sponsor or its affiliates in excess of unreturned and unreimbursed capital invested by the Company’s sponsor and its affiliates into the Company, the Advisor, the Company’s dealer manager, or affiliates, relating in any way to the business organization of the Company, the Operating Partnership, or any offering of the Company, shall be subordinated to the return of stockholders’ invested capital. Such excess merger consideration shall be paid in stock that may not be traded for one year from the date of receipt, and such stock shall be held in escrow pending the occurrence of certain conditions outlined further in the operating partnership agreement. (1) The Advisor cannot earn more than one incentive distribution. Any receipt by the Advisor of subordinated share of net sale proceeds (for anything other than a sale of the entire portfolio) will reduce the amount of the subordinated distribution due upon termination, the subordinated incentive listing distribution and the subordinated distribution due upon extraordinary transaction. Conflicts of Interest The Sponsor, Advisor, Property Manager and their officers and certain of their key personnel and their respective affiliates currently serve as key personnel, advisors, managers and sponsors or co-sponsors to some or all of 12 other programs affiliated with the Sponsor, including Griffin Capital Essential Asset REIT II, Inc. (“GCEAR II”), Griffin-American Healthcare REIT III, Inc. (“GAHR III”), and Griffin-American Healthcare REIT IV, Inc. (“GAHR IV”), each of which are publicly-registered, non-traded real estate investment trusts, and Griffin Institutional Access Real Estate Fund (“GIA Real Estate Fund”) and Griffin Institutional Access Credit Fund (“GIA Credit Fund”), both of which are non-diversified, closed-end management investment companies that are operated as interval funds under the Investment Company Act of 1940, as amended (the “1940 Act”). Because these persons have competing demands on their time and resources, they may have conflicts of interest in allocating their time between the Company’s business and these other activities. Some of the material conflicts that the Sponsor, Advisor, and Property Manager and their key personnel and their respective affiliates will face are (1) competing demand for time of the Advisor’s executive officers and other key personnel from the Sponsor and other affiliated entities; (2) determining if certain investment opportunities should be recommended to the Company or another program sponsored or co-sponsored by the Sponsor; and (3) influence of the fee structure under the Advisory Agreement and the distribution structure under the operating partnership agreement that could result in actions not necessarily in the long-term best interest of the Company’s stockholders. The board of directors has adopted the Sponsor’s acquisition allocation policy as to the allocation of acquisition opportunities among the Company and GCEAR II, which is based on the following factors: • the investment objectives of each program; • the amount of funds available to each program; • the financial impact of the acquisition on each program, including each program’s earnings and distribution ratios; • various strategic considerations that may impact the value of the investment to each program; • the effect of the acquisition on concentration/diversification of each program’s investments; and • the income tax effects of the purchase to each program. In the event all acquisition allocation factors have been exhausted and an investment opportunity remains equally suitable for the Company and GCEAR II, the Sponsor will offer the investment opportunity to the REIT that has had the longest period of time elapse since it was offered an investment opportunity. If the Sponsor no longer sponsors GCEAR II, then, in the event that an investment opportunity becomes available that is suitable, under all of the factors considered by the Advisor, for both the Company and one or more other entities affiliated with the Sponsor, the Sponsor has agreed to present such investment opportunities to the Company first, prior to presenting such opportunities to any other programs sponsored by or affiliated with the Sponsor. In determining whether or not an investment opportunity is suitable for more than one program, the Advisor, subject to approval by the board of directors, shall examine, among others, the following factors: • anticipated cash flow of the property to be acquired and the cash requirements of each program; • effect of the acquisition on diversification of each program’s investments; • policy of each program relating to leverage of properties; • income tax effects of the purchase to each program; • size of the investment; • no significant increase in the cost of financing; and • amount of funds available to each program and the length of time such funds have been available for investment. Economic Dependency The Company will be dependent on the Advisor for certain services that are essential to the Company, including the identification, evaluation, negotiation, purchase and disposition of properties and other investments, management of the daily operations of the Company’s real estate portfolio, and other general and administrative responsibilities. In the event that the Advisor is unable to provide the services, the Company will be required to obtain such services from other resources.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Other Commitments [Line Items]
Commitments and Contingencies	Commitments and Contingencies Litigation From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company is not a party to any material legal proceedings, nor is the Company aware of any pending or threatened litigation that would have a material adverse effect on the Company’s business, operating results, cash flows or financial condition should such litigation be resolved unfavorably.	Commitments and Contingencies Litigation From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company is not a party to any material legal proceedings, nor is the Company aware of any pending or threatened litigation that would have a material adverse effect on the Company’s business, operating results, cash flows or financial condition should such litigation be resolved unfavorably.
Griffin Capital Essential Asset REIT, Inc. [Member]
Other Commitments [Line Items]
Commitments and Contingencies	Commitments and Contingencies Ground Lease Obligations The Company acquired properties on January 16, 2014 and April 10, 2018 that are subject to ground leases with expiration dates of December 2095 and September 2102, respectively. The Company incurred rent expense of approximately $1.3 million for the nine months ended September 30, 2018 and 2017 , related to the ground leases. As of September 30, 2018 , the remaining required payments under the terms of the ground leases are as follows: September 30, 2018 Remaining 2018 $ 258 2019 1,032 2020 1,032 2021 1,032 2022 1,072 Thereafter 200,446 Total $ 204,872 Litigation From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company is not a party to any material legal proceedings, nor is the Company aware of any pending or threatened litigation that would have a material adverse effect on the Company’s business, operating results, cash flows or financial condition should such litigation be resolved unfavorably.	Commitments and Contingencies Ground Lease Obligations The Company acquired a property on January 16, 2014 that is subject to a ground lease with an expiration date of December 31, 2095. The Company incurred rent expense of approximately $0.4 million for the years ended December 31, 2017 and 2016 , related to the ground lease. As of December 31, 2017 , the remaining required payments under the terms of the ground lease are as follows: December 31, 2017 2018 $ 198 2019 198 2020 198 2021 198 2022 218 Thereafter 33,631 Total $ 34,641 Litigation From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company is not a party to any material legal proceedings, nor is the Company aware of any pending or threatened litigation that would have a material adverse effect on the Company’s business, operating results, cash flows or financial condition should such litigation be resolved unfavorably.

Declaration of Distributions

Declaration of Distributions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Dividends Payable [Line Items]
Declaration of Distributions	Declaration of Distributions During the quarter ended September 30, 2018 , the Company paid cash distributions in the amount of $0.0015068493 per day, before adjustments of class-specific expenses, per Class T share, Class S share, Class D share, Class I share, Class A share, Class AA share and Class AAA share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from July 1, 2018 through September 30, 2018. Such distributions payable to each stockholder of record were paid on such date after the end of each month during the period as determined by the Company's Chief Executive Officer. On September 12, 2018 , the Company’s board of directors declared cash distributions in the amount of $0.0015068493 per day, subject to adjustments for class-specific expenses, per Class T share, Class S share, Class D share, Class I share, Class A share, Class AA share, and Class AAA on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from October 1, 2018 through December 31, 2018. Such distributions payable to each stockholder of record will be paid on such date after the end of each month during the period as determined by the Company's Chief Executive Officer.	Declaration of Distributions The Company paid cash distributions in the amount of $0.00150684932 per day, before adjustments of class-specific expenses, per Class T share, Class S share, Class D share, Class I share, Class A share, Class AA share and Class AAA share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from September 20, 2017 through December 31, 2017 . Such distributions payable to each stockholder of record were paid on such date after the end of each month during the period as determined by the Company’s Chief Executive Officer. On December 4, 2017, the Company’s board of directors declared cash distributions in the amount of $0.00150684932 per day, subject to adjustments for class-specific expenses, per Class T share, Class S share, Class D share, Class I share, Class A share, Class AA share, and Class AAA on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from January 1, 2018 through March 31, 2018. Such distributions payable to each stockholder of record will be paid on such date after the end of each month during the period as determined by the Company’s Chief Executive Officer.
Griffin Capital Essential Asset REIT, Inc. [Member]
Dividends Payable [Line Items]
Declaration of Distributions	Declaration of Distributions During the quarter ended September 30, 2018 , the Company paid distributions in the amount of $0.001901096 per day per share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from July 1, 2018 through September 30, 2018 . Such distributions were paid on a monthly basis, on or about the first day of the month, for the month then-ended. On September 12, 2018 , the Company’s board of directors declared distributions in the amount of $0.001901096 per day per share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from October 1, 2018 through December 31, 2018. Such distributions payable to each stockholder of record during a month will be paid on such date of the following month as the Company’s Chief Executive Officer may determine.	Declaration of Distributions During the quarter ended December 31, 2017 , the Company paid distributions in the amount of $0.001901096 per day per share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from October 1, 2017 through December 31, 2017 . Such distributions were paid on a monthly basis, on or about the first day of the month, for the month then-ended. On December 12, 2017 , the Company’s board of directors declared distributions in the amount of $0.001901096 per day per share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from January 1, 2018 through March 31, 2018. Such distributions payable to each stockholder of record during a month will be paid on such date of the following month as the Company’s Chief Executive Officer may determine.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited) Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information [Line Items]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) Presented below is a summary of the unaudited quarterly financial information for the years ended December 31, 2017 and 2016 : 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue $ 25,972 $ 26,546 $ 27,349 $ 27,514 Net income $ 3,124 $ 3,365 $ 3,099 $ 1,531 Net income attributable to common stockholders $ 3,123 $ 3,364 $ 3,098 $ 1,531 Net income per share (1) $ 0.04 $ 0.04 $ 0.04 $ 0.03 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue $ 12,502 $ 13,330 $ 16,334 $ 20,646 Net (loss)/income $ (1,141 ) $ (2,825 ) $ (2,736 ) $ 595 Net (loss)/income attributable to common stockholders $ (1,140 ) $ (2,824 ) $ (2,735 ) $ 595 Net (loss)/income per share (1) $ (0.03 ) $ (0.06 ) $ (0.05 ) $ 0.01 (1) Amounts were retroactively adjusted to reflect stock dividends. (See Note 2, Basis of Presentation and Summary of Significant Accounting Policies, for additional details).
Griffin Capital Essential Asset REIT, Inc. [Member]
Quarterly Financial Information [Line Items]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) Presented below is a summary of the unaudited quarterly financial information for the years ended December 31, 2017 and 2016 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue $ 96,708 $ 82,772 $ 85,132 $ 81,878 Income before other income and (expenses) $ 26,787 $ 17,685 $ 22,394 $ 15,428 Net income $ 14,306 $ 9,160 $ 9,445 $ 113,222 Net income attributable to common stockholders $ 13,726 $ 8,756 $ 9,029 $ 109,146 Net income attributable to common stockholders per share $ 0.08 $ 0.05 $ 0.05 $ 0.64 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue (1) $ 86,732 $ 86,588 $ 86,736 $ 84,218 Income before other income and (expenses) $ 22,973 $ 18,841 $ 19,378 $ 12,339 Net income $ 12,386 $ 6,581 $ 7,131 $ 457 Net income attributable to common stockholders $ 11,891 $ 6,248 $ 6,795 $ 351 Net income attributable to common stockholders per share $ 0.07 $ 0.04 $ 0.04 $ — (1) Amounts were reclassified to conform to the current period presentation. See Note 2, Basis of Presentation and Summary of Significant Accounting Policies, for additional details.

Subsequent Events

Subsequent Events	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Subsequent Events		Subsequent Events Offering Status As of November 7, 2018, the Company had issued 7,372,224 shares of the Company’s common stock pursuant to the DRP and Follow-On Offering for approximately $70.2 million . Redemptions On October 1, 2018, the Company paid approximately $6.7 million at a weighted average price per share of $9.62 related to redemption payables.	Subsequent Events Status of the Offering As of March 7, 2018 , the Company had issued 4,818,911 and 299,515 shares of the Company’s common stock pursuant to the DRP and follow-on offering, respectively, for approximately $45.6 million and $2.8 million , respectively. Redemptions On January 31, 2018, the Company redeemed 217,088 shares of common stock for approximately $2.0 million at a weighted average price per share of $9.09 . Declaration of Distributions On March 8, 2018, the Company’s board of directors declared cash distributions in the amount of $0.00150684932 per day, subject to adjustments for class-specific expenses, per Class T share, Class S share, Class D share, Class I share, Class A share, Class AA share, and Class AAA on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from April 1, 2018 through June 30, 2018. Such distributions payable to each stockholder of record will be paid on such date after the end of each month during the period as determined by the Company’s Chief Executive Officer. Performance Distribution The Company’s Advisor holds a special limited partner interest in the Operating Partnership that entitles it to receive a special distribution from the Operating Partnership equal to 12.5% of the total return, subject to certain limitations, which is paid annually (See Note 10, Related Party Transactions , for additional details). On February 16, 2018, the Company paid in cash approximately $1.2 million and issued approximately $1.2 million in limited partnership units to the Advisor.
Griffin Capital Essential Asset REIT, Inc. [Member]
Subsequent Event [Line Items]
Subsequent Events	Subsequent Events Offering Status As of November 7, 2018 , the Company had issued 22,100,900 shares of the Company’s common stock pursuant to the DRP Offerings for approximately $226.3 million . Redemptions On October 31, 2018, the Company redeemed 681,757 shares of common stock for approximately $6.7 million at a weighted average price per share of $9.76 . Sale of Property On November 2, 2018, the Company sold the Quad Graphics property located in Loveland, Colorado for total proceeds of $10.7 million , which includes $3.9 million in termination fees, less closing costs and other closing credits. The carrying value of the property on the closing date was approximately $9.9 million . Determination of Estimated Value Per Share On October 24, 2018, the Company's board of directors approved an estimated value per share of the Company's common stock of $10.05 based on the estimated value of the Company's assets less the estimated value of the liabilities, or net asset value, divided by the number of shares outstanding on a fully diluted basis, calculated as of June 30, 2018. The Company is providing this estimated value per share to assist broker dealers in connection with their obligations under applicable Financial Industry Regulatory Authority rules with respect to customer account statements. This valuation was performed in accordance with the methodology provided in Practice Guideline 2013-01, Valuations of Publicly Registered Non-Listed REITs, issued by the Institute for Portfolio Alternatives in April 2013, in addition to guidance from the SEC. See the Company's Current Report on Form 8-K filed with the SEC on October 26, 2018 for a description of the methodologies and assumptions used to determine, and the limitations of, the estimated value per share.		Subsequent Events Offering Status As of March 7, 2018, the Company had issued 19,135,619 shares of the Company’s common stock pursuant to the DRP Offerings for approximately $196.5 million . Declaration of Distributions On March 7, 2018, the Company’s board of directors declared distributions in the amount of $0.001901096 per day per share on the outstanding shares of common stock payable to stockholders of record at the close of business on each day during the period from April 1, 2018 through June 30, 2018. Such distributions payable to each stockholder of record during a month will be paid on such date of the following month as the Company’s Chief Executive Officer may determine. Charter Filings On March 8, 2018, the Company filed a Certificate of Correction (the “Certificate of Correction”) to the Company’s Fourth Articles of Amendment and Restatement with the State Department of Assessments and Taxation of Maryland (the “SDAT”). The Certificate of Correction was filed to correct a scrivener’s error in Section 7.1 of the Fourth Articles of Amendment and Restatement. On March 8, 2018, the Company filed Articles Supplementary with the SDAT to elect to become subject to Section 3-804(c) of the Maryland General Corporation Law with respect to any vacancy of any member of the board of directors that is elected by stockholders. Amendment to Bylaws On March 7, 2018, the board of directors amended the Company’s Amended and Restated Bylaws to add new Article XV designating the Circuit Court for Baltimore City, Maryland (or, if that Court does not have jurisdiction, the United States District Court for the District of Maryland, Baltimore Division) as the exclusive forum for certain proceedings relating to the Company, as set forth in the new article. Amendment to SRP On March 7, 2018, the board of directors amended the Company’s SRP to clarify which stockholders may participate in the SRP. A description of the SRP, as amended, is included as Exhibit 4.3 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 and is incorporated herein by reference.

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation Schedule III - Real Estate and Accumulated Depreciation - Rollforward of Accumulated Depreciation	12 Months Ended
	Dec. 31, 2017
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Schedule III - Real Estate and Accumulated Depreciation	Initial Cost to Company Cost Capitalized Subsequent to Acquisition Gross Carrying Amount at Life on which depreciation in latest income statement is computed Property Property Type ST Encumbrances Land Building and Improvements (1) Building and Land Building and Improvements Total Accumulated Depreciation and Amortization Date of Construction Date of Acquisition Owens Corning Industrial NC $ 3,300 $ 575 $ 5,167 $ — $ 575 $ 5,167 $ 5,742 $ 485 N/A 3/9/2015 5-40 years Westgate II Office TX 34,200 3,732 55,101 — 3,732 55,101 58,833 6,488 N/A 4/1/2015 5-40 years Administrative Office of Pennsylvania Courts Office PA 6,070 1,207 8,936 — 1,207 8,936 10,143 994 N/A 4/22/2015 5-40 years American Express Center Data Center/Office AZ 54,900 5,750 113,670 — 5,750 113,670 119,420 17,706 N/A 5/11/2015 5-40 years MGM Corporate Center Office NV 18,180 4,260 28,705 405 4,260 29,110 33,370 3,387 N/A 5/27/2015 5-40 years American Showa Industrial OH 10,320 1,453 15,747 — 1,453 15,747 17,200 1,475 N/A 5/28/2015 5-40 years Huntington Ingalls Industrial VA — 5,415 29,836 18 5,415 29,854 35,269 2,778 N/A 6/26/2015 5-40 years Wyndham Office NJ — 5,696 76,532 — 5,696 76,532 82,228 6,601 N/A 6/26/2015 5-40 years Exel Distribution Center OH — 1,988 13,958 — 1,988 13,958 15,946 1,461 N/A 6/30/2015 5-40 years Rapiscan Systems Office MA — 2,350 9,482 — 2,350 9,482 11,832 1,132 N/A 7/1/2015 5-40 years FedEx Freight Industrial OH — 2,774 25,913 — 2,774 25,913 28,687 2,331 N/A 7/22/2015 5-40 years Aetna Office AZ — 1,853 20,481 — 1,853 20,481 22,334 1,243 N/A 7/29/2015 5-40 years Bank of America I Office CA — 5,491 23,514 138 5,491 23,652 29,143 3,724 N/A 8/14/2015 5-40 years Bank of America II Office CA — 9,206 20,204 — 9,206 20,204 29,410 3,674 N/A 8/14/2015 5-40 years Atlas Copco Office MI — 1,480 16,490 — 1,480 16,490 17,970 1,626 N/A 10/1/2015 5-40 years Toshiba TEC Office NC — 4,130 36,821 — 4,130 36,821 40,951 2,691 N/A 1/21/2016 5-40 years NETGEAR Office CA — 20,726 25,887 43 20,726 25,930 46,656 2,148 N/A 5/17/2016 5-40 years Nike Office OR — 5,988 42,397 24 5,988 42,421 48,409 4,603 N/A 6/16/2016 5-40 years Zebra Technologies Office IL — 5,238 56,526 — 5,238 56,526 61,764 3,843 N/A 8/1/2016 5-40 years WABCO Industrial SC — 1,302 12,598 — 1,302 12,598 13,900 682 N/A 9/14/2016 5-40 years IGT Office NV — 6,325 64,441 40 6,325 64,481 70,806 2,695 N/A 9/27/2016 5-40 years 3M Industrial IL — 5,320 62,247 — 5,320 62,247 67,567 2,475 N/A 10/25/2016 5-40 years Amazon Industrial OH — 5,331 85,770 — 5,331 85,770 91,101 2,903 N/A 11/18/2016 5-40 years Zoetis Office NJ — 3,375 42,265 — 3,375 42,265 45,640 1,749 N/A 12/16/2016 5-40 years Southern Company Office AL — 6,605 122,679 45 6,605 122,724 129,329 3,488 N/A 12/22/2016 5-40 years Allstate Office CO — 1,808 14,090 200 1,808 14,290 16,098 679 N/A 1/31/2017 5-40 years MISO Office IN — 3,104 26,014 — 3,104 26,014 29,118 844 N/A 5/15/2017 5-40 years Total (3) $ 126,970 $ 122,482 $ 1,055,471 $ 913 $ 122,482 $ 1,056,384 $ 1,178,866 $ 83,905 (1) Building and improvements include tenant origination and absorption costs. (2) The acquisitions were funded by the credit facility. (3) As of December 31, 2017 , the aggregate cost of real estate the Company and consolidated subsidiaries own for federal income tax purposes was approximately $1.1 billion (unaudited). Activity for the year ended December 31, 2017 2016 2015 Real estate facilities Balance at beginning of year $ 1,133,055 $ 516,965 $ — Acquisitions 45,016 615,972 516,965 Improvements 576 38 — Construction-in-progress 219 80 — Balance at end of year $ 1,178,866 $ 1,133,055 $ 516,965 Accumulated depreciation Balance at beginning of year $ 39,955 $ 12,061 $ — Depreciation and amortization expense 43,950 27,894 12,061 Balance at end of year $ 83,905 $ 39,955 $ 12,061 Real estate facilities, net $ 1,094,961 $ 1,093,100 $ 504,904
Griffin Capital Essential Asset REIT, Inc. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Schedule III - Real Estate and Accumulated Depreciation	GRIFFIN CAPITAL ESSENTIAL ASSET REIT, INC. SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION (Dollars in thousands) Initial Cost to Company (2) Cost Gross Carrying Amount at December 31, 2017 Life on Property Property ST Encumbrances (1) Land Building and Building and Land Building and Improvements Total Accumulated Date of Date of Plainfield Office/Laboratory IL $ — $ 3,709 $ 27,335 $ 2,217 $ 3,709 $ 29,552 $ 33,261 $ 11,477 N/A 6/18/2009 5-40 years Renfro Warehouse/Distribution SC 13,320 1,400 18,804 1,390 1,400 20,194 21,594 7,075 N/A 6/18/2009 5-40 years Emporia Partners Office/Industrial/Distribution KS 2,978 274 7,567 — 274 7,567 7,841 2,378 N/A 8/27/2010 5-40 years Quad/Graphics Industrial/Office CO 7,400 1,950 10,236 292 1,950 10,528 12,478 2,723 N/A 12/30/2010 5-40 years AT&T Office/ Data Center WA 25,655 6,770 32,420 461 6,770 32,881 39,651 8,535 N/A 1/31/2012 5-40 years Westinghouse Engineering Facility PA 21,708 2,650 26,745 — 2,650 26,745 29,395 6,193 N/A 3/22/2012 5-40 years TransDigm Office GA 4,539 3,773 9,030 408 3,773 9,438 13,211 2,350 N/A 5/31/2012 5-40 years Travelers Office CO 9,374 2,600 13,500 873 2,600 14,373 16,973 3,771 N/A 6/29/2012 5-40 years Zeller Manufacturing IL 8,880 2,674 13,229 651 2,674 13,880 16,554 2,654 N/A 11/8/2012 5-40 years Northrop Office OH 10,667 1,300 16,188 39 1,300 16,227 17,527 5,057 N/A 11/13/2012 5-40 years Health Net Office CA 13,321 4,182 18,072 — 4,182 18,072 22,254 5,520 N/A 12/18/2012 5-40 years Comcast Office CO — 3,146 22,826 1,517 3,146 24,343 27,489 6,705 N/A 1/11/2013 5-40 years Boeing Office WA — 3,000 9,000 102 3,000 9,102 12,102 4,377 N/A 2/15/2013 5-40 years Schlumberger Office TX 29,689 2,800 47,752 145 2,800 47,897 50,697 8,090 N/A 5/1/2013 5-40 years UTC Office NC 23,467 1,330 37,858 — 1,330 37,858 39,188 6,982 N/A 5/3/2013 5-40 years Avnet Research & Development/Flex Facility AZ 19,615 1,860 31,481 — 1,860 31,481 33,341 5,724 N/A 5/29/2013 5-40 years Cigna Office AZ 375,000 (4) 8,600 48,102 — 8,600 48,102 56,702 8,811 N/A 6/20/2013 5-40 years Nokia Office IL — 7,697 21,843 — 7,697 21,843 29,540 3,362 N/A 8/13/2013 5-40 years Verizon Office NJ 25,837 5,300 36,768 2,010 5,300 38,778 44,078 9,858 N/A 10/3/2013 5-40 years Fox Head Office CA — 3,672 23,230 — 3,672 23,230 26,902 3,442 N/A 10/29/2013 5-40 years Coca-Cola Refreshments Office GA — 5,000 50,227 1,946 5,000 52,173 57,173 11,845 N/A 11/5/2013 5-40 years General Electric Office GA — (4) 5,050 51,396 153 5,050 51,549 56,599 7,398 N/A 11/5/2013 5-40 years Atlanta Wildwood Office GA — 4,189 23,414 1,612 4,189 25,026 29,215 6,523 N/A 11/5/2013 5-40 years Community Insurance Office OH — 1,177 22,323 — 1,177 22,323 23,500 3,883 N/A 11/5/2013 5-40 years Anthem Office OH — 850 8,892 — 850 8,892 9,742 2,071 N/A 11/5/2013 5-40 years JPMorgan Chase Office OH — 5,500 39,000 212 5,500 39,212 44,712 6,531 N/A 11/5/2013 5-40 years Initial Cost to Company (2) Cost Gross Carrying Amount at December 31, 2017 Life on Property Property ST Encumbrances (1) Land Building and Building and Land Building and Improvements Total Accumulated Date of Date of IBM Office OH — 4,750 32,769 391 4,750 33,160 37,910 8,037 N/A 11/5/2013 5-40 years Aetna Office TX — 3,000 12,330 185 3,000 12,515 15,515 3,245 N/A 11/5/2013 5-40 years CHRISTUS Health Office TX — (4) 1,950 46,922 332 1,950 47,254 49,204 9,145 N/A 11/5/2013 5-40 years Roush Industries Office MI — 875 11,375 534 875 11,909 12,784 2,979 N/A 11/5/2013 5-40 years Wells Fargo Office WI — 3,100 26,348 6,217 3,100 32,565 35,665 12,475 N/A 11/5/2013 5-40 years Shire Pharmaceuticals Office PA — 2,925 18,935 715 2,925 19,650 22,575 6,865 N/A 11/5/2013 5-40 years United HealthCare Office MO — 2,920 23,510 283 2,920 23,793 26,713 5,983 N/A 11/5/2013 5-40 years Northpointe Corporate Center II Office WA — 1,109 6,066 4,576 1,109 10,642 11,751 2,003 N/A 11/5/2013 5-40 years Comcast (Northpointe Corporate Center I) Office WA — (4) 2,292 16,930 1,571 2,292 18,501 20,793 3,957 N/A 11/5/2013 5-40 years Farmers Office KS — 2,750 17,106 51 2,750 17,157 19,907 3,511 N/A 12/27/2013 5-40 years Caterpillar Industrial IL — 6,000 46,511 — 6,000 46,511 52,511 10,717 N/A 1/7/2014 5-40 years DigitalGlobe Office CO — 8,600 83,400 — 8,600 83,400 92,000 12,692 N/A 1/14/2014 5-40 years Waste Management Office AZ — — 16,515 10 — 16,525 16,525 3,057 N/A 1/16/2014 5-40 years BT Infonet Office CA — 9,800 41,483 — 9,800 41,483 51,283 7,082 N/A 2/27/2014 5-40 years Wyndham Worldwide Office NJ — 6,200 91,153 — 6,200 91,153 97,353 10,609 N/A 4/23/2014 5-40 years Ace Hardware Office IL — (4) 6,900 33,945 — 6,900 33,945 40,845 4,795 N/A 4/24/2014 5-40 years Equifax I Office MO — 1,850 12,709 78 1,850 12,787 14,637 2,504 N/A 5/20/2014 5-40 years American Express Office AZ — 15,000 45,893 — 15,000 45,893 60,893 11,792 N/A 5/22/2014 5-40 years SoftBank Office CA — 22,789 68,950 3,400 22,789 72,350 95,139 17,454 N/A 5/28/2014 5-40 years Vanguard Office NC — 2,230 31,062 — 2,230 31,062 33,292 4,570 N/A 6/19/2014 5-40 years Restoration Hardware Industrial CA — (4) 15,463 — 74,213 15,463 74,213 89,676 8,135 8/15/2015 6/20/2014 5-40 years Parallon Office FL — 1,000 16,772 — 1,000 16,772 17,772 2,442 N/A 6/25/2014 5-40 years TW Telecom Office CO 19,169 10,554 35,817 1,240 10,554 37,057 47,611 5,721 N/A 8/1/2014 5-40 years Equifax II Office MO — 2,200 12,755 70 2,200 12,825 15,025 2,015 N/A 10/1/2014 5-40 years Mason I Office OH — 4,777 18,489 — 4,777 18,489 23,266 1,457 N/A 11/7/2014 5-40 years Wells Fargo Office NC — (4) 2,150 40,806 46 2,150 40,852 43,002 4,907 N/A 12/15/2014 5-40 years GE Aviation Office OH — 4,400 61,681 — 4,400 61,681 66,081 9,046 N/A 2/19/2015 5-40 years Westgate III Office TX — 3,209 75,937 — 3,209 75,937 79,146 7,727 N/A 4/1/2015 5-40 years Lisle Office IL — 2,788 16,200 33 2,788 16,233 19,021 2,860 N/A 6/10/2015 5-40 years Bloomingdale Office IL — 588 2,986 — 588 2,986 3,574 794 N/A 6/10/2015 5-40 years Columbia Office MD — 6,989 46,875 171 6,989 47,046 54,035 5,433 N/A 6/10/2015 5-40 years Denver Office CO — 9,948 23,888 3,670 9,948 27,558 37,506 2,806 N/A 6/10/2015 5-40 years Columbus Office OH — 2,943 22,651 133 2,943 22,784 25,727 3,802 N/A 6/10/2015 5-40 years Miramar Office FL — 4,488 19,979 591 4,488 20,570 25,058 2,994 N/A 6/10/2015 5-40 years Initial Cost to Company (2) Cost Gross Carrying Amount at December 31, 2017 Life on Property Property ST Encumbrances (1) Land Building and Building and Land Building and Improvements Total Accumulated Date of Date of Irving Carpenter Office TX — (4) 1,842 22,052 3,463 1,842 25,515 27,357 2,142 N/A 6/10/2015 5-40 years Frisco Office TX — (4) 8,239 51,395 3,917 8,239 55,312 63,551 5,720 N/A 6/10/2015 5-40 years Houston Westway II Office TX — 3,961 78,668 — 3,961 78,668 82,629 10,791 N/A 6/10/2015 5-40 years Houston Westway I Office TX — 6,540 30,703 — 6,540 30,703 37,243 4,622 N/A 6/10/2015 5-40 years Atlanta Perimeter Office GA — (4) 8,607 96,718 447 8,607 97,165 105,772 14,370 N/A 6/10/2015 5-40 years Herndon Office VA — 9,666 74,098 — 9,666 74,098 83,764 9,679 N/A 6/10/2015 5-40 years Deerfield Office IL — 4,339 37,298 1,032 4,339 38,330 42,669 8,467 N/A 6/10/2015 5-40 years Highway 94 Office MO 17,352 5,637 25,280 — 5,637 25,280 30,917 2,636 N/A 11/6/2015 5-40 years DynCorp Office TX — 1,952 15,540 — 1,952 15,540 17,492 2,040 N/A 12/11/2015 5-40 years Mercedes-Benz Office TX — 2,330 26,376 — 2,330 26,376 28,706 3,369 N/A 12/11/2015 5-40 years Samsonite Office FL 22,961 5,040 42,490 — 5,040 42,490 47,530 3,140 N/A 12/11/2015 5-40 years Lynwood III & IV Land WA — 2,865 — — 2,865 — 2,865 — N/A 3/17/2016 N/A HealthSpring Office TN 21,694 8,126 31,447 — 8,126 31,447 39,573 2,503 N/A 4/27/2016 5-40 years Fort Mill Office SC — 4,612 86,352 — 4,612 86,352 90,964 222 N/A 11/30/2017 5-40 years Fort Mill II Office SC — 1,275 41,507 — 1,275 41,507 42,782 105 N/A 11/30/2017 5-40 years Total All Properties (3) $ 672,626 $ 342,021 $ 2,405,910 $ 121,397 $ 342,021 $ 2,527,307 $ 2,869,328 $ 426,752 (1) Amount does not include the net loan valuation discount of $0.3 million related to the debt assumed in the Highway 94, Samsonite and HealthSpring property acquisitions. (2) Building and improvements include tenant origination and absorption costs. (3) As of December 31, 2017, the aggregate cost of real estate the Company and consolidated subsidiaries own for federal income tax purposes was approximately $2.9 billion (unaudited). (4) The Bank of America Loan is secured by cross-collateralized and cross-defaulted first mortgage liens on the proper Activity for the Year Ended December 31, 2017 2016 2015 Real estate facilities Balance at beginning of year $ 3,024,389 $ 2,968,982 $ 1,823,895 Acquisitions 133,747 42,438 1,087,153 Improvements 12,479 16,792 7,382 Construction-in-progress 1,752 575 45,067 Other adjustments (2,785 ) (4,398 ) — Real estate assets held and used — — 70,907 Write down of tenant origination and absorption costs (2,352 ) — — Sale of real estate assets (297,902 ) — (65,422 ) Balance at end of year $ 2,869,328 $ 3,024,389 $ 2,968,982 Accumulated depreciation Balance at beginning of year $ 338,552 $ 208,933 $ 102,883 Depreciation and amortization expense 116,583 130,849 112,748 Depreciation expense (held and used adjustment) — — 4,621 Less: Non-real estate assets depreciation expense (1,554 ) (1,230 ) (328 ) Less: Sale of real estate assets depreciation expense (26,829 ) — (10,991 ) Balance at end of year $ 426,752 $ 338,552 $ 208,933 Real estate facilities, net $ 2,442,576 $ 2,685,837 $ 2,760,049

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Accounting Policies [Line Items]
Consolidation		Principles of Consolidation The Company’s financial statements, and the financial statements of the Company’s Operating Partnership, including its wholly-owned subsidiaries, are consolidated in the accompanying consolidated financial statements. The portion of these entities not wholly-owned by the Company is presented as noncontrolling interests. All significant intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the unaudited consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates.	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates.
Change in Consolidated Financial Statements Presentation	Change in Consolidated Financial Statements Presentation During the year ended December 31, 2017, the Company elected to early adopt Accounting Standards Update ("ASU") No. 2016-18, Restricted Cash ("ASU No. 2016-18"). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the consolidated statements of cash flows.	Change in Consolidated Financial Statements Presentation Certain amounts in the Company’s prior period consolidated financial statements have been reclassified to conform to the current period presentation. During the year ended December 31, 2017, the Company elected to early adopt Accounting Standards Update (“ASU”) No. 2016-18 (as discussed below). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the consolidated statements of cash flows.
Per Share Data	Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common stock outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common stock outstanding, including common stock equivalents. As of September 30, 2018 and December 31, 2017 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders.	Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding, including common stock equivalents. As of December 31, 2017 and December 31, 2016 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders. The Company retroactively adjusted the number of shares of common stock outstanding in accordance with ASC 260-10, Earnings per Share. ASC 260-10 requires retroactively adjusting the computations of basic and diluted earnings per share for all periods presented to reflect the change in capital structure, if the number of shares of common stock outstanding increases as a result of a stock dividend or stock split or decreases as a result of a reverse stock split. If changes in common stock resulting from stock dividends, stock splits, or reverse stock splits occur after the close of the period but before the consolidated financial statements are issued or are available to be issued, the per-share computations for those and any prior-period consolidated financial statements presented shall be based on the new number of shares.
Segment Information	Segment Information ASC Topic 280, Segment Reporting , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment.	Segment Information ASC Topic 280, Segment Reporting , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging ("ASU No. 2017-12") . 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards, a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. This ASU is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company elected to early adopt ASU No. 2017-12 for the reporting period ending March 31, 2018. The adoption of ASU No. 2017-12 did not have a material effect on the Company's financial position or statement of operations. In February 2016, the FASB issued ASU No. 2016-02, Leases ("ASU No. 2016-02"). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued an amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which states that: (a) an entity need not reassess whether any expired or existing contracts are leases or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in May 2017 board meeting minutes that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In March 2018, the FASB approved a proposal to the drafting of an amendment to the ASU to allow lessors to elect, as a practical expedient, not to allocate the total consideration to lease and non-lease components based on their relative standalone selling prices. If adopted, this single-lease component practical expedient will allow lessors to elect a combined single-lease component presentation if (i) the timing and pattern of transfer of the lease component and the non-lease component(s) associated with it are the same, and (ii) the lease component would be classified as an operating lease if it were accounted for separately. Non-lease components that do not meet the criteria of this practical expedient and combined components in which the non-lease component is the predominant component will be accounted for under the new revenue recognition ASU. The Company does not expect that ASU No. 2016-02 will impact the Company's accounting for Fixed Lease Payments because the Company's accounting policy is currently consistent with the provisions of the standard. The Company is currently evaluating the impact of the standard as it relates to Non-Lease Payments. If the practical expedient mentioned above is adopted and the Company elects it, the Company expects payments for expense reimbursements that qualify as Non-Lease Payments will be presented under a single lease component presentation. However, without the proposed practical expedient, the Company expects these reimbursements would be separated into Fixed Lease Payments and Non-Lease Payments. Under ASU No. 2016-02, reimbursements relating to property taxes and insurances are Fixed Lease Payments as the payments relates to the right to use the leased assets, while reimbursements relating to maintenance activities and common area expense are Non-Lease Payments and would be accounted under ASU No. 2014-09 upon the adoption of the ASU No. 2016-02 as these payments for goods or services are transferred separately from the right to use the underlying assets. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 replaces substantially all industry-specific revenue recognition requirements and converges areas under this topic with International Financial Reporting Standards. ASU No. 2014-09 implements a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. ASU No. 2014-09 also requires enhanced disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows from contracts with customers. Other major provisions in ASU No. 2014-09 include capitalizing and amortizing certain contract costs, ensuring the time value of money is considered in the applicable transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. ASU No. 2014-09 was originally effective for reporting periods beginning after December 31, 2016 (for public entities). On April 1, 2015, the FASB voted to defer the effective date of ASU No. 2014-09 by one year to annual reporting periods beginning after December 15, 2017. On July 9, 2015, the FASB affirmed its proposal to defer the effective date to annual reporting periods beginning after December 15, 2017, although entities may elect to adopt the standard as of the original effective date. The Company adopted the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The impact was minimal upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of gains and losses on the sale of real estate assets as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Rental income from leasing arrangements is a substantial portion of the Company’s revenue, is specifically excluded from ASU No. 2014-09 and will be governed by the applicable lease codification ("ASU No. 2016-02"). In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU No. 2016-08"). The amendments clarify how an entity should identify the unit of accounting (i.e., the specified good or service) for the principal versus agent evaluation, and how it should apply the control principle to certain types of arrangements, such as service transactions, by explaining what a principal controls before the specified good or service is transferred to the customer. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements of ASU No. 2014-09 described above. The Company adopted the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The impact was minimal upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of reporting revenue gross versus net on its consolidated financial statements as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle.	Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (“ASU No. 2017-12”), that simplifies hedge accounting. 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. ASU No. 2017-12 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. For cash flow hedges in existence at the date of adoption, an entity is required to apply a cumulative-effect adjustment for previously recognized ineffectiveness from retained earnings to accumulated other comprehensive income (“AOCI”), as of the beginning of the fiscal year when an entity adopts the amendments in this ASU. The Company utilizes interest rate hedge agreements to hedge a portion of exposure to variable interest rates primarily associated with borrowings based on London Interbank Offered Rate (“LIBOR”). As a result, all interest rate hedge agreements are designated as cash flow hedges. During the years ended December 31, 2017 and December 31, 2016 , the ineffectiveness related to the Company’s interest rate hedge agreement was immaterial. Therefore, the Company does not believe ASU No. 2017-12 would have an impact on operating results for the year ended December 31, 2017 . In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (“ASU No. 2017-01”), that clarified the definition of a business. ASU No. 2017-01 is effective for reporting periods beginning after December 15, 2017, with early adoption permitted. The Company adopted this update on October 1, 2016. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash (“ASU No. 2016-18”), that will require companies to include restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This ASU will require a disclosure of a reconciliation between the statement of financial position and the statement of cash flows when the statement of financial position includes more than one line item for cash, cash equivalents, restricted cash, and restricted cash equivalents. Entities with material restricted cash and restricted cash equivalents balances will be required to disclose the nature of the restrictions. This ASU is effective for reporting periods beginning after December 15, 2017, with early adoption permitted, and will be applied retrospectively to all periods presented. The Company elected to early adopt ASU No. 2016-18 for the reporting period ending December 31, 2017 and applied retrospectively to all periods presented. As a result of the adoption of ASU No. 2016-18, the Company no longer presents the changes within restricted cash in the consolidated statements of cash flows. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU No. 2016-15”). ASU No. 2016-15 addresses eight specific cash flow issues with the objective of reducing diversity in practice. The cash flow issues include debt prepayment or debt extinguishment costs and proceeds from the settlement of insurance claims. This ASU is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The Company elected to early adopt ASU No. 2016-15 for the reporting period ending December 31, 2017. There was no change to the Company’s consolidated financial statements or notes as a result of adoption. In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU No. 2016-02”). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued a proposed amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which allows for (a) an entity need not to reassess whether any expired or existing contracts are or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in board meeting minutes of May 2017 that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In January, 2018, the FASB issued a proposed amendment to ASU No. 2016-02 that would allow lessors to elect, as a practical expedient, not to allocate the total consideration to Fixed Lease Payments and Non-Lease Payments based on their relative standalone selling prices. If adopted, this practical expedient will allow lessors to elect a combined single component presentation if (i) the timing and pattern of the revenue recognition for the Fixed Lease Payments and Non-Lease Payments are the same, and (ii) the combined single component of the lease would continue to be classified as an operating lease. The Company does not expect that ASU 2016-02 will impact the Company’s accounting for Fixed Lease Payments, because the Company’s accounting policy is currently consistent with the provisions of the standard. The Company is currently evaluating the impact of the standard as it relates to Non-Lease Payments. If the proposed practical expedient mentioned above is adopted and the Company elects it, the Company expects payments for expense reimbursements that qualify as Non-Lease Payments will be presented under a single lease component presentation. However, without the proposed practical expedient, the Company expects these reimbursements would be separated into Fixed Lease Payments and Non-Lease Payments. Under ASU No. 2016-02, reimbursements relating to property taxes and insurances are Fixed Lease Payments as the payments relates to the right to use the leased assets, while reimbursements relating to maintenance activities and common area expense are Non-Lease Payments and would be accounted under ASU No. 2014-09 upon the adoption of the ASU No. 2016-02 as these payments for goods or services are transferred separately from the right to use the underlying assets. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 replaces substantially all industry-specific revenue recognition requirements and converges areas under this topic with International Financial Reporting Standards. ASU No. 2014-09 implements a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. ASU No. 2014-09 also requires enhanced disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows from contracts with customers. Other major provisions in ASU No. 2014-09 include capitalizing and amortizing certain contract costs, ensuring the time value of money is considered in the applicable transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. ASU No. 2014-09 was originally effective for reporting periods beginning after December 31, 2016 (for public entities). On April 1, 2015, the FASB voted to defer the effective date of ASU No. 2014-09 by one year to annual reporting periods beginning after December 15, 2017. On July 9, 2015, the FASB affirmed its proposal to defer the effective date to annual reporting periods beginning after December 15, 2017, although entities may elect to adopt the standard as of the original effective date. The Company intends to adopt the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The Company anticipates minimal impact upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of gains and losses on the sale of real estate assets as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Rental income from leasing arrangements is a substantial portion of the Company’s revenue, is specifically excluded from ASU No. 2014-09 and will be governed by the applicable lease codification (“ASU No. 2016-02”). In conjunction with the adoption of the leasing guidance, the Company is currently in the process of evaluating certain variable payment terms included in these lease arrangements which are governed by ASU No. 2014-09. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations ( Reporting Revenue Gross versus Net “ASU No. 2016-08”). The amendments clarify how an entity should identify the unit of accounting (i.e., the specified good or service) for the principal versus agent evaluation, and how it should apply the control principle to certain types of arrangements, such as service transactions, by explaining what a principal controls before the specified good or service is transferred to the customer. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements of ASU No. 2014-09 described above. The Company intends to adopt the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The Company anticipates minimal impact upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of reporting revenue gross versus net on its consolidated financial statements as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle.
Revenue Recognition, Policy [Policy Text Block]		Revenue Recognition Leases associated with the acquisition and contribution of certain real estate assets (see Note 3, Real Estate ) have net minimum rent payment increases during the term of the lease and are recorded to rental revenue on a straight-line basis, commencing as of the contribution or acquisition date. If a lease provides for contingent rental income, the Company will defer the recognition of contingent rental income, such as percentage rents, until the specific target that triggers the contingent rental income is achieved. Tenant reimbursement revenue, which is comprised of additional amounts collected from tenants for the recovery of certain operating expenses, including repair and maintenance, property taxes and insurance, and capital expenditures, to the extent allowed pursuant to the lease (collectively, “Recoverable Expenses”), is recognized as revenue when the additional rent is due. Recoverable Expenses to be reimbursed by a tenant are determined based on the Company’s estimate of the property’s operating expenses for the year, pro rated based on leased square footage of the property, and are collected in equal installments as additional rent from the tenant, pursuant to the terms of the lease. At least quarterly, the Company reconciles the amount of additional rent paid by the tenant during the quarter to the actual amount of the Recoverable Expenses incurred by the Company for the same period. The difference, if any, is either charged or credited to the tenant pursuant to the provisions of the lease. In certain instances, the lease may restrict the amount the Company can recover from the tenant such as a cap on certain or all property operating expenses.
Derivatives, Policy [Policy Text Block]		Derivative Instruments and Hedging Activities ASC Topic 815: Derivatives and Hedgin g (“ASC 815”), provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, ASC 815 requires qualitative disclosures regarding the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company recorded all derivatives on the consolidated balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, and whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. See Note 5, Interest Rate Contracts .
Regulatory Income Taxes, Policy [Policy Text Block]		Income Taxes The Company has elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”) for the year ended December 31, 2015. To qualify as a REIT, the Company must meet certain organizational and operational requirements, including a requirement to currently distribute at least 90% of the REIT’s ordinary taxable income to stockholders. As a REIT, the Company generally will not be subject to federal income tax on taxable income that is distributed to stockholders. If the Company fails to qualify as a REIT in any taxable year, after the Company initially qualifies to be taxed as a REIT, the Company will then be subject to federal income taxes on the taxable income at regular corporate rates and will not be permitted to qualify for treatment as a REIT for federal income tax purposes for four years following the year during which qualification is lost unless the Internal Revenue Service grants the Company relief under certain statutory provisions. Such an event could materially adversely affect net income and net cash available for distribution to stockholders. However, the Company believes that it is organized and will operate in such a manner as to qualify for treatment as a REIT and intends to operate in the foreseeable future in such a manner that it will remain qualified as a REIT for federal income tax purposes. The Company could engage in certain business activities that could have an adverse effect on its REIT qualification. The Company has elected to isolate these business activities in the books and records of the TRS. In general, the TRS may perform additional services for the Company’s tenants and generally may engage in any real estate or non-real estate related business. The TRS will be subject to corporate federal and state income tax. As of December 31, 2017 , the TRS has not commenced operations.
Unaudited Data [Policy Text Block]		Unaudited Data Any references to the number of buildings, square footage, number of leases, occupancy, and any amounts derived from these values in the notes to the consolidated financial statements are unaudited and outside the scope of the Company’s independent registered public accounting firm’s audit of its consolidated financial statements in accordance with the standards of the Public Company Accounting Oversight Board.
Real Estate, Policy [Policy Text Block]		Real Estate Purchase Price Allocation In January 2017, the FASB issued ASU No. 2017-01, Business Combinations, (see “Recently Issued Accounting Pronouncements” below) that clarifies the framework for determining whether an integrated set of assets and activities meets the definition of a business. The revised framework establishes a screen for determining whether an integrated set of assets and activities is a business and 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. This update is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2017, with early adoption permitted for transactions that have not been reported in previously issued (or available to be issued) financial statements. The Company adopted this accounting standard early effective October 1, 2016. As a result of the Company’s adoption of ASU No. 2017-01, Business Combinations, the Company anticipates that many of its future acquisitions will be treated as asset acquisitions, which will result in a lower amount of acquisition-related costs being expensed on the Company’s consolidated statement of operations, as the majority of those costs will be capitalized and included as part of the relative fair value allocation of the purchase price. The Company applies the provisions in ASC 805-10, Business Combinations , to account for the acquisition of real estate, or real estate related assets, in which a lease, or other contract, is in place representing an active revenue stream, as an asset acquisition (in rare cases, a business combination). In accordance with the provisions of ASC 805-10 (on an asset acquisition), the Company recognizes an asset acquisition, the assets acquired, the liabilities assumed and any noncontrolling interest in the acquired entity at their relative fair values. The accounting provisions have also established that transaction costs associated with an asset acquisition are capitalized. Acquired in-place leases are valued as above-market or below-market as of the date of acquisition. The valuation is measured based on the present value (using an interest rate, which reflects the risks associated with the leases acquired) of the difference between (a) the contractual amounts to be paid pursuant to the in-place leases and (b) management’s estimate of fair market lease rates for the corresponding in-place leases over a period equal to the remaining non-cancelable term of the lease for above-market leases, taking into consideration below-market extension options for below-market leases. In addition, renewal options are considered and will be included in the valuation of in-place leases if (1) it is likely that the tenant will exercise the option, and (2) the renewal rent is considered to be sufficiently below a fair market rental rate at the time of renewal. The above-market and below-market lease values are capitalized as intangible lease assets or liabilities and amortized as an adjustment to rental income over the remaining terms of the respective leases. The aggregate relative fair value of in-place leases includes direct costs associated with obtaining a new tenant, opportunity costs associated with lost rentals, which are avoided by acquiring an in-place lease, and tenant relationships. Direct costs associated with obtaining a new tenant include commissions, tenant improvements, and other direct costs and are estimated using methods similar to those used in independent appraisals and management’s consideration of current market costs to execute a similar lease. These direct costs are considered intangible lease assets and are included with real estate assets on the consolidated balance sheets. The intangible lease assets are amortized to expense over the remaining terms of the respective leases. The value of opportunity costs is calculated using the contractual amounts to be paid, including real estate taxes, insurance, and other operating expenses, pursuant to the in-place leases over a market lease-up period for a similar lease. Customer relationships are valued based on management’s evaluation of certain characteristics of each tenant’s lease and the Company’s overall relationship with that respective tenant. Characteristics management will consider in allocating these values include the nature and extent of the Company’s existing business relationships with tenants, growth prospects for developing new business with the tenant, the tenant’s credit quality and expectations of lease renewals (including those existing under the terms of the lease agreement), among other factors. These intangibles will be included in intangible lease assets on the consolidated balance sheets and are amortized to expense over the remaining term of the respective leases. The determination of the relative fair values of the assets and liabilities acquired requires the use of significant assumptions about current market rental rates, rental growth rates, discount rates and other variables.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]		Restricted Cash In conjunction with acquisitions of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash. As of December 31, 2017 , the Company had approximately $12.9 million in restricted cash, which includes tenant improvement funds.
Cash and Cash Equivalents, Policy [Policy Text Block]		Cash and Cash Equivalents The Company considers all short-term, highly liquid investments that are readily convertible to cash with a maturity of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents may include cash and short-term investments. Short-term investments are stated at cost, which approximates fair value. There were no cash equivalents, nor were there restrictions on the use of the Company’s cash balance as of December 31, 2017 and 2016 . The Company maintains its cash accounts with major financial institutions. The cash balances consist of business checking accounts. These accounts are insured by the Federal Deposit Insurance Corporation up to $250,000 at each institution. The Company has not experienced any losses with respect to cash balances in excess of government provided insurance. Management believes there was no significant concentration of credit risk with respect to these cash balances as of December 31, 2017 .
Depreciation, Depletion, and Amortization [Policy Text Block]		Depreciation and Amortization The purchase price of real estate acquired and the costs related to development, construction, and property improvements are capitalized. Repairs and maintenance costs include all costs that do not extend the useful life of the real estate asset and are expensed as incurred. The Company considers the period of future benefit of an asset to determine the appropriate useful life. The Company anticipates the estimated useful lives of its assets by class to be generally as follows: Buildings 40 years Building Improvements 5-20 years Land Improvements 15-25 years Tenant Improvements Shorter of estimated useful life or remaining contractual lease term Tenant Origination and Absorption Cost Remaining contractual lease term In-place Lease Valuation Remaining contractual lease term with consideration as to below-market extension options for below-market leases If a lease is terminated or amended prior to its scheduled expiration, the Company will accelerate the remaining useful life of the unamortized lease-related costs.
Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy [Policy Text Block]		Impairment of Real Estate and Related Intangible Assets The Company continually monitors events and changes in circumstances that could indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, including credit ratings of all tenants to stay abreast of any material changes in credit quality. The Company monitors tenant credit by (1) reviewing the credit ratings of tenants (or their parent companies or lease guarantors) that are rated by nationally recognized rating agencies; (2) reviewing financial statements and related metrics and information that are publicly available or that are required to be provided pursuant to the lease; (3) monitoring news reports and press releases regarding the tenants (or their parent companies or lease guarantors), and their underlying business and industry; and (4) monitoring the timeliness of rent collections. When indicators of potential impairment are present that indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, management assesses whether the carrying value of the assets will be recovered through the future undiscounted operating cash flows expected from the use of the assets and the eventual disposition. If, based on this analysis, the Company does not believe that it will be able to recover the carrying value of the asset, the Company will record an impairment charge to the extent the carrying value exceeds the net present value of the estimated future cash flows of the asset. Projections of expected future undiscounted cash flows require management to estimate future market rental income amounts subsequent to the expiration of current lease agreements, property operating expenses, discount rates, the number of months it takes to re-lease the property and the number of years the property is held for investment. For the year ended December 31, 2017 , the Company did not record any impairment charges related to its real estate assets or intangible assets .
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Consolidation		Principles of Consolidation The Company’s financial statements, and the financial statements of the Company’s Operating Partnership, including its wholly-owned subsidiaries, are consolidated in the accompanying consolidated financial statements. The portion of these entities not wholly-owned by the Company is presented as noncontrolling interests. All significant intercompany accounts and transactions have been eliminated in consolidation. Consolidation Considerations Current accounting guidance provides a framework for identifying a variable interest entity (“VIE”) and determining when a company should include the assets, liabilities, noncontrolling interests, and results of activities of a VIE in its consolidated financial statements. In general, a VIE is an entity or other legal structure used to conduct activities or hold assets that either (1) has an insufficient amount of equity to carry out its principal activities without additional subordinated financial support, (2) has a group of equity owners that are unable to make significant decisions about its activities, or (3) has a group of equity owners that do not have the obligation to absorb losses or the right to receive returns generated by its operations. Generally, a VIE should be consolidated if a party with an ownership, contractual, or other financial interest in the VIE (a variable interest holder) has the power to direct the VIE’s most significant activities and the obligation to absorb losses or right to receive benefits of the VIE that could be significant to the VIE. A variable interest holder that consolidates the VIE is called the primary beneficiary. Upon consolidation, the primary beneficiary generally must initially record all of the VIE’s assets, liabilities, and noncontrolling interest at fair value and subsequently account for the VIE as if it were consolidated based on majority voting interest. See Note 4, Investments .
Use of Estimates		Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Use of Estimates The preparation of the unaudited consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates.
Change in Consolidated Financial Statements Presentation		Change in Consolidated Financial Statements Presentation Certain amounts in the Company’s prior period consolidated financial statements have been reclassified to conform to the current period presentation. Property expense recovery reimbursements are presented gross on the statement of operations for all periods presented. During the year ended December 31, 2017, the Company elected to early adopt ASU No. 2016-18 (as defined below). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the consolidated statements of cash flows. Change in Consolidated Financial Statements Presentation Certain amounts in the Company's prior period consolidated financial statements have been reclassified to conform to the current period presentation. During the year ended December 31, 2017, the Company elected to early adopt Accounting Standards Update ("ASU") No. 2016-18, Restricted Cash ("ASU No. 2016-18"). As a result, the Company no longer presents transfers between cash and restricted cash in the consolidated statements of cash flows. Instead, restricted cash is included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the consolidated statements of cash flows. Recoverable state tax expenses have been reclassified from general and administrative expenses to property operating expenses on the statement of operations for all periods presented. Certain amounts in the Company's prior period consolidated financial statements have been reclassified to conform to the current period presentation. See Assets Held for Sale in Note 3, Real Estate .
Per Share Data		Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding, including common stock equivalents. As of December 31, 2017 and December 31, 2016 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders. Per Share Data The Company reports earnings per share for the period as (1) basic earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding during the period, and (2) diluted earnings per share computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding, including common stock equivalents. As of September 30, 2018 and December 31, 2017 , there were no material common stock equivalents that would have a dilutive effect on earnings (loss) per share for common stockholders.
Segment Information		Segment Information Segment Reporting (“ ASC 280 ”) , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment. Segment Information ASC Topic 280, Segment Reporting , establishes standards for reporting financial and descriptive information about a public entity’s reportable segments. The Company internally evaluates all of the properties and interests therein as one reportable segment.
Recently Issued Accounting Pronouncements		Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging. 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. The ASU is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. For cash flow hedges in existence at the date of adoption, an entity is required to apply a cumulative-effect adjustment for previously recognized ineffectiveness from retained earnings to accumulated other comprehensive income, as of the beginning of the fiscal year when an entity adopts the amendments in this ASU. The Company utilizes interest rate hedge agreements to hedge a portion of exposure to variable interest rates primarily associated with borrowings based on London Interbank Offered Rate (“LIBOR”). As a result, all interest rate hedge agreements are designated as cash flow hedges. During the years ended December 31, 2017 and 2016, the ineffectiveness related to the Company’s interest rate hedge agreements was immaterial. Therefore, the Company does not believe this ASU would have an impact on operating results for the year ended December 31, 2017 . In January 2017, the FASB issued ASU No. 2017-01, Business Combinations, that clarified the definition of a business. The ASU is effective for reporting periods beginning after December 15, 2017, with early adoption permitted. The Company adopted this update on January 1, 2017. Refer to “ Real Estate Purchase Price Allocation ” above for a discussion of this accounting pronouncement. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , that will require companies to include restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The ASU will require a disclosure of a reconciliation between the statement of financial position and the statement of cash flows when the statement of financial position includes more than one line item for cash, cash equivalents, restricted cash, and restricted cash equivalents. Entities with material restricted cash and restricted cash equivalents balances will be required to disclose the nature of the restrictions. This ASU is effective for reporting periods beginning after December 15, 2017, with early adoption permitted, and will be applied retrospectively to all periods presented. The Company elected to early adopt ASU No. 2016-18 for the reporting period ending December 31, 2017 and apply this ASU retrospectively to all periods presented. As a result of the adoption of ASU No. 2016-18, the Company no longer presents the changes within restricted cash in the consolidated statements of cash flows. In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments . ASU No. 2016-15 addresses eight specific cash flow issues with the objective of reducing diversity in practice. The cash flow issues include debt prepayment or debt extinguishment costs and proceeds from the settlement of insurance claims. This ASU is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The Company elected to early adopt ASU No. 2016-15 for the reporting period ending December 31, 2017. There was no change to the Company’s consolidated financial statements or notes as a result of adoption. In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU No. 2016-02”). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued a proposed amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which allows for (a) an entity need not to reassess whether any expired or existing contracts are or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in board meeting minutes of May 2017 that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In January, 2018, the FASB issued a proposed amendment to ASU No. 2016-02 that would allow lessors to elect, as a practical expedient, not to allocate the total consideration to Fixed Lease Payments and Non-Lease Payments based on their relative standalone selling prices. If adopted, this practical expedient will allow lessors to elect a combined single component presentation if (i) the timing and pattern of the revenue recognition for the Fixed Lease Payments and Non-Lease Payments are the same, and (ii) the combined single component of the lease would continue to be classified as an operating lease. The Company does not expect that ASU 2016-02 will impact the Company’s accounting for Fixed Lease Payments, because the Company’s accounting policy is currently consistent with the provisions of the standard. The Company is currently evaluating the impact of the standard as it relates to Non-Lease Payments. If the proposed practical expedient mentioned above is adopted and the Company elects it, the Company expects payments for expense reimbursements that qualify as Non-Lease Payments will be presented under a single lease component presentation. However, without the proposed practical expedient, the Company expects these reimbursements would be separated into Fixed Lease Payments and Non-Lease Payments. Under ASU No. 2016-02, reimbursements relating to property taxes and insurances are Fixed Lease Payments as the payments relates to the right to use the leased assets, while reimbursements relating to maintenance activities and common area expense are Non-Lease Payments and would be accounted under ASU No. 2014-09 upon the adoption of the ASU No. 2016-02 as these payments for goods or services are transferred separately from the right to use the underlying assets. Additionally, the Company is analyzing its current ground lease obligation under ASU No. 2016-02. The Company has done a preliminary assessment and continues to evaluate the potential impact the guidance may have on its consolidated financial statements and related disclosures and will adopt ASU No. 2016-02 as of January 1, 2019. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 replaces substantially all industry-specific revenue recognition requirements and converges areas under this topic with International Financial Reporting Standards. ASU No. 2014-09 implements a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. ASU No. 2014-09 also requires enhanced disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows from contracts with customers. Other major provisions in ASU No. 2014-09 include capitalizing and amortizing certain contract costs, ensuring the time value of money is considered in the applicable transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. ASU No. 2014-09 was originally effective for reporting periods beginning after December 31, 2016 (for public entities). On April 1, 2015, the FASB voted to defer the effective date of ASU No. 2014-09 by one year to annual reporting periods beginning after December 15, 2017. On July 9, 2015, the FASB affirmed its proposal to defer the effective date to annual reporting periods beginning after December 15, 2017, although entities may elect to adopt the standard as of the original effective date. The Company intends to adopt the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The Company anticipates minimal impact upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of gains and losses on the sale of real estate assets as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Rental income from leasing arrangements is a substantial portion of the Company’s revenue, is specifically excluded from ASU No. 2014-09 and will be governed by the applicable lease codification (ASU No. 2016-02). In conjunction with the adoption of the leasing guidance, the Company is currently in the process of evaluating certain variable payment terms included in these lease arrangements which are governed by ASU No. 2014-09. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) . The amendments clarify how an entity should identify the unit of accounting (i.e., the specified good or service) for the principal versus agent evaluation, and how it should apply the control principle to certain types of arrangements, such as service transactions, by explaining what a principal controls before the specified good or service is transferred to the customer. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements of ASU No. 2014-09. The Company intends to adopt the guidance using the modified retrospective approach for the fiscal year beginning January 1, 2018. The Company anticipates minimal impact upon adoption of the new accounting guidance on its consolidated financial statements relating to the recognition of reporting revenue gross versus net on its consolidated financial statements as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Recently Issued Accounting Pronouncements In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging ("ASU No. 2017-12"). 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. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in other comprehensive income and to be reclassified into earnings only when the hedged item impacts earnings. Current guidance requires a periodic recognition of hedge ineffectiveness in earnings. Under existing standards a quantitative assessment is made on an ongoing basis to determine if a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Under the new standard, entities will still be required to perform an initial quantitative test. However, the new standard allows entities to elect to subsequently perform only a qualitative assessment unless facts and circumstances change. This ASU is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company elected to early adopt ASU No. 2017-12 for the reporting period ending March 31, 2018. The adoption of ASU No. 2017-12 did not have a material effect on the Company's financial position or statement of operations. In February 2016, the FASB issued ASU No. 2016-02, Leases ("ASU No. 2016-02"). ASU No. 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. ASU No. 2016-02 will direct how the Company accounts for payments from the elements of leases that are generally fixed and determinable at the inception of the lease (“Fixed Lease Payments”) while ASU No. 2014-09 (defined below) will direct how the Company accounts for the non-lease components of lease contracts, primarily expense reimbursements (“Non-Lease Payments”) and the accounting for the disposition of real estate facilities. ASU No. 2016-02 will be effective beginning in the first quarter of 2019. Early adoption of ASU No. 2016-02 as of its issuance is permitted. ASU No. 2016-02 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. Based on the required adoption date of January 1, 2019, the modified retrospective method for ASU No. 2016-02 requires application of the standard to all leases that exist at, or commence after, January 1, 2017 (beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of accumulated earnings (deficit) on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. The FASB has also issued an amendment to the standard that would provide an entity an optional transition method to initially account for the impact of the adoption of the standard with a cumulative adjustment to accumulated earnings (deficit) on January 1, 2019 (the effective date of ASU No. 2016-02), rather than January 1, 2017, which would eliminate the need to restate amounts presented prior to January 1, 2019. Under ASU No. 2016-02, an entity may elect a practical expedient package, which states that: (a) an entity need not reassess whether any expired or existing contracts are leases or contain leases; (b) an entity need not reassess the lease classification for any expired or existing leases; and (c) an entity need not reassess initial direct costs for any existing leases. These three practical expedients are available as a single election that must be elected as a package and must be consistently applied to all existing leases at the date of adoption. The FASB has also tentatively noted in its May 2017 board meeting minutes that lessors that adopt this package of practical expedients are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017 under ASU No. 2016-02, or January 1, 2019, if the Company elects the optional transition method. The FASB noted that the transition provisions generally enable entities to “run off” their existing leases for the remainder of the lease term, which would effectively eliminate the need to calculate adjustment to the opening balance of accumulated earnings (deficit). In March 2018, the FASB approved a proposal to the drafting of an amendment to ASU No. 2016-02 to allow lessors to elect, as a practical expedient, not to allocate the total consideration to lease and non-lease components based on their relative standalone selling prices. If adopted, this single-lease component practical expedient will allow lessors to elect a combined single-lease component presentation if (i) the timing and pattern of transfer of the lease component and the non-lease component(s) associated with it are the same, and (ii) the lease component would be classified as an operating lease if it were accounted for separately. Non-lease components that do not meet the criteria of this practical expedient and combined components in which the non-lease component is the predominant component will be accounted for under the new ASU No. 2016-02. The Company does not expect that ASU No. 2016-02 will impact the Company's accounting for Fixed Lease Payments because the Company's accounting policy is currently consistent with the provisions of the standard. The Company is currently evaluating the impact of the standard as it relates to Non-Lease Payments. If the practical expedient mentioned above is adopted and the Company elects it, the Company expects payments for expense reimbursements that qualify as Non-Lease Payments will be presented under a single lease component presentation. However, without the proposed practical expedient, the Company expects these reimbursements would be separated into Fixed Lease Payments and Non-Lease Payments. Under ASU No. 2016-02, reimbursements relating to property taxes and insurances are Fixed Lease Payments as the payments relate to the right to use the leased assets, while reimbursements relating to maintenance activities and common area expense are Non-Lease Payments and would be accounted under ASU No. 2014-09 upon the adoption of the ASU No. 2016-02 as these payments for goods or services are transferred separately from the right to use the underlying assets. Additionally, the Company is analyzing its current ground lease obligation under ASU No. 2016-02 where the Company is the lessee. The Company has done a preliminary assessment and continues to evaluate the potential impact the guidance may have on its consolidated financial statements and related disclosures and will adopt ASU No. 2016-02 as of January 1, 2019. The Company is the lessee under two ground leases. The Company believes that the application of this standard will result in the recording of a right of use asset and the related lease liability for the ground leases. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU No. 2014-09”). ASU No. 2014-09 replaces substantially all industry-specific revenue recognition requirements and converges areas under this topic with International Financial Reporting Standards. ASU No. 2014-09 implements a five-step process for customer contract revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards. ASU No. 2014-09 also requires enhanced disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows from contracts with customers. Other major provisions in ASU No. 2014-09 include capitalizing and amortizing certain contract costs, ensuring the time value of money is considered in the applicable transaction price, and allowing estimates of variable consideration to be recognized before contingencies are resolved in certain circumstances. ASU No. 2014-09 was originally effective for reporting periods beginning after December 31, 2016 (for public entities). On April 1, 2015, the FASB voted to defer the effective date of ASU No. 2014-09 by one year to annual reporting periods beginning after December 15, 2017. On July 9, 2015, the FASB affirmed its proposal to defer the effective date to annual reporting periods beginning after December 15, 2017, although entities may elect to adopt the standard as of the original effective date. The Company adopted the guidance using the modified retrospective approach for the fiscal year beginning on January 1, 2018. The impact of the adoption of the new accounting guidance was minimal on the Company's consolidated financial statements relating to the recognition of gains and losses on the sale of real estate assets was minimal as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle. Rental income from leasing arrangements is a substantial portion of the Company’s revenue, is specifically excluded from ASU No. 2014-09 and will be governed by the applicable lease codification, ASU No. 2016-02. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU No. 2016-08"). The amendments clarify how an entity should identify the unit of accounting (i.e., the specified good or service) for the principal versus agent evaluation, and how it should apply the control principle to certain types of arrangements, such as service transactions, by explaining what a principal controls before the specified good or service is transferred to the customer. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements of ASU No. 2014-09 described above. The Company adopted the guidance using the modified retrospective approach for the fiscal year beginning on January 1, 2018. The impact of the adoption of the new accounting guidance was minimal on the Company's consolidated financial statements relating to the recognition of reporting revenue gross versus net on the Company's consolidated financial statements as the Company’s current accounting for such transactions is consistent with the new guidance’s core principle.
Revenue Recognition, Policy [Policy Text Block]		Revenue Recognition Leases associated with the acquisition and contribution of certain real estate assets have net minimum rent payment increases during the term of the lease and are recorded to rental revenue on a straight-line basis, commencing as of the contribution or acquisition date. If a lease provides for contingent rental income, the Company will defer the recognition of contingent rental income, such as percentage rents, until the specific target that triggers the contingent rental income is achieved. Tenant reimbursement revenue, which is comprised of additional amounts collected from tenants for the recovery of certain operating expenses, including repair and maintenance, property taxes and insurance, and capital expenditures, to the extent allowed pursuant to the lease (collectively, “Recoverable Expenses”), is recognized as revenue when the additional rent is due. Recoverable Expenses to be reimbursed by a tenant are determined based on the Company’s estimate of the property’s operating expenses for the year, pro rated based on leased square footage of the property, and are collected in equal installments as additional rent from the tenant, pursuant to the terms of the lease. At the end of each quarter, the Company reconciles the amount of additional rent paid by the tenant during the quarter to the actual amount of the Recoverable Expenses incurred by the Company for the same period. The difference, if any, is either charged or credited to the tenant pursuant to the provisions of the lease. In certain instances, the lease may restrict the amount the Company can recover from the tenant such as a cap on certain or all property operating expenses. In a situation in which a lease associated with a significant tenant has been, or is expected to be, terminated early, or extended, the Company evaluates the remaining useful life of amortizable assets in the asset group related to the lease that will be terminated (i.e., above- and below-market lease intangibles, in-place lease value and deferred leasing costs). Based upon consideration of the facts and circumstances surrounding the termination or extension, the Company may write-off or accelerate the amortization associated with the asset group. Such amounts are included within rental and other income for above- and below-market lease intangibles and amortization for the remaining lease related asset groups in the consolidated statements of operations.
Derivatives, Policy [Policy Text Block]		Derivative Instruments and Hedging Activities FASB ASC 815: Derivatives and Hedging (“ASC 815”) provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, ASC 815 requires qualitative disclosures regarding the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company recorded all derivatives on the consolidated balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, and whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. See Note 6, Interest Rate Contracts .
Regulatory Income Taxes, Policy [Policy Text Block]		Income Taxes The Company has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). To qualify as a REIT, the Company must meet certain organizational and operational requirements. The Company intends to adhere to these requirements and maintain its REIT status for the current year and subsequent years. As a REIT, the Company generally will not be subject to federal income taxes on taxable income that is distributed to stockholders. However, the Company may be subject to certain state and local taxes on its income and property, and federal income and excise taxes on its undistributed taxable income, if any. If the Company fails to qualify as a REIT in any taxable year, the Company will then be subject to federal income taxes on the taxable income at regular corporate rates and will not be permitted to qualify for treatment as a REIT for federal income tax purposes for four years following the year during which qualification is lost unless the Internal Revenue Service (“IRS”) grants the Company relief under certain statutory provisions. Such an event could materially adversely affect net income and net cash available for distribution to stockholders. As of December 31, 2017 , the Company satisfied the REIT requirements and distributed all of its taxable income. Pursuant to the Code, the Company has elected to treat its corporate subsidiary as a TRS. In general, the TRS may perform non-customary services for the Company’s tenants and may engage in any real estate or non real estate-related business. The TRS will be subject to corporate federal and state income tax. As of December 31, 2017 , the TRS had not commenced operations.
Unaudited Data [Policy Text Block]		Unaudited Data Any references to the number of buildings, square footage, number of leases, occupancy, and any amounts derived from these values in the notes to the consolidated financial statements are unaudited and outside the scope of the Company’s independent registered public accounting firm’s audit of its consolidated financial statements in accordance with the standards of the Public Company Accounting Oversight Board (“PCAOB”).
Real Estate Held for Development and Sale, Policy [Policy Text Block]		Assets Held for Sale The Company accounts for properties held for sale in accordance with ASC 360, Property, Plant, and Equipment , (“ASC 360”), which addresses financial accounting and reporting for the impairment or disposal of long-lived assets and ASC 2014-08, Presentation of Financial Statements (“ASC 205”) and Property, Plant, and Equipment: Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity (“ASU No. 2014-08”). Under ASU No. 2014-08, a discontinued operation is (i) a component of an entity or group of components that has been disposed of by sale, that has been disposed of other than by sale, or that is classified as held for sale that represents a strategic shift that has or will have a major effect on an entity’s operations and financial results or (ii) an acquired business or nonprofit activity that is classified as held for sale on the date of the acquisition. In accordance with ASC 205, a component of an entity or a group of components of an entity, or a business or nonprofit activity (the entity to be sold) shall be classified as held for sale in the period in which all of the required criteria are met. In accordance with ASC 360, upon being classified as held for sale, a property is carried at the lower of (i) its carrying amount or (ii) fair value less costs to sell. In addition, a property being held for sale ceases to be depreciated. Assets Reclassified from Held for Sale to Held and Used Upon the Company’s determination to discontinue marketing properties for sale, the properties will no longer meet the held for sale criteria and are required to be reclassified as held and used at the lower of adjusted carrying value (carrying value of the properties prior to being classified as held for sale adjusted for any depreciation and/or amortization expense that would have been recognized had the properties been continuously classified as held and used) or its fair value at the date of the subsequent decision not to sell. If adjusted carrying value is determined to be lower, a catch up adjustment will be recorded. The depreciation and/or amortization expenses that would have been recognized had the properties been continuously classified as held and used will be included as a component of depreciation and amortization expense in the accompanying consolidated statements of operations. If fair value is determined to be lower, the Company will record a loss included in income or loss from continuing operations in the accompanying consolidated statements of operations.
Real Estate, Policy [Policy Text Block]		Real Estate Purchase Price Allocation In January 2017, the FASB issued Accounting Standards Update (“ASU”) No. 2017-01, Business Combinations, (see “Recently Issued Accounting Pronouncements” below) that clarifies the framework for determining whether an integrated set of assets and activities meets the definition of a business. The revised framework establishes a screen for determining whether an integrated set of assets and activities is a business and 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. This update is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2017, with early adoption permitted for transactions that have not been reported in previously issued (or available to be issued) financial statements. The Company adopted this accounting standard early effective January 1, 2017. As a result of the Company’s adoption of ASU No. 2017-01, Business Combinations, the Company anticipates that many of its future acquisitions (if any) will be treated as asset acquisitions, which will result in a lower amount of acquisition-related costs being expensed on the Company’s consolidated statement of operations, as the majority of those costs will be capitalized and included as part of the relative fair value allocation of the purchase price. The Company applies the provisions in ASC 805-10, Business Combinations , to account for the acquisition of real estate, or real estate related assets, in which a lease, or other contract, is in place representing an active revenue stream, as an asset acquisition (in rare cases, a business combination). In accordance with the provisions of ASC 805-10 (on an asset acquisition), the Company recognizes the assets acquired, the liabilities assumed and any noncontrolling interest in the acquired entity at their relative fair values. The accounting provisions have also established that transaction costs associated with an asset acquisition are capitalized. Acquired in-place leases are valued as above-market or below-market as of the date of acquisition. The valuation is measured based on the present value (using an interest rate, which reflects the risks associated with the leases acquired) of the difference between (a) the contractual amounts to be paid pursuant to the in-place leases and (b) management’s estimate of fair market lease rates for the corresponding in-place leases over a period equal to the remaining non-cancelable term of the lease for above-market leases, taking into consideration below-market extension options for below-market leases. In addition, renewal options are considered and will be included in the valuation of in-place leases if (1) it is likely that the tenant will exercise the option, and (2) the renewal rent is considered to be sufficiently below a fair market rental rate at the time of renewal. The above-market and below-market lease values are capitalized as intangible lease assets or liabilities and amortized as an adjustment to rental income over the remaining terms of the respective leases. The aggregate relative fair value of in-place leases includes direct costs associated with obtaining a new tenant, opportunity costs associated with lost rentals, which are avoided by acquiring an in-place lease, and tenant relationships. Direct costs associated with obtaining a new tenant include commissions, tenant improvements, and other direct costs and are estimated using methods similar to those used in independent appraisals and management’s consideration of current market costs to execute a similar lease. These direct costs are considered intangible lease assets and are included with real estate assets on the consolidated balance sheets. The intangible lease assets are amortized to expense over the remaining terms of the respective leases. The value of opportunity costs is calculated using the contractual amounts to be paid, including real estate taxes, insurance, and other operating expenses, pursuant to the in-place leases over a market lease-up period for a similar lease. Customer relationships are valued based on management’s evaluation of certain characteristics of each tenant’s lease and the Company’s overall relationship with that respective tenant. Characteristics management will consider in allocating these values include the nature and extent of the Company’s existing business relationships with tenants, growth prospects for developing new business with the tenant, the tenant’s credit quality and expectations of lease renewals (including those existing under the terms of the lease agreement), among other factors. These intangibles will be included in intangible lease assets on the consolidated balance sheets and are amortized to expense over the remaining term of the respective leases. The determination of the relative fair values of the assets and liabilities acquired requires the use of significant assumptions about current market rental rates, rental growth rates, discount rates and other variables.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]		Restricted Cash Restricted cash primarily consists of cash proceeds from dispositions that are temporarily held at qualified intermediaries for purposes of facilitating potential exchanges under Section 1031 of the Code (“Section 1031 Exchanges”). In addition, in conjunction with acquisitions of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash.
Cash and Cash Equivalents, Policy [Policy Text Block]		Cash and Cash Equivalents The Company considers all short-term, highly liquid investments that are readily convertible to cash with a maturity of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents may include cash and short-term investments. Short-term investments are stated at cost, which approximates fair value. There were no cash equivalents, nor were there restrictions on the use of the Company’s cash balance as of December 31, 2017 and 2016 . The Company maintains its cash accounts with major financial institutions. The cash balances consist of business checking accounts. These accounts are insured by the Federal Deposit Insurance Corporation up to $250,000 at each institution. The Company has not experienced any losses with respect to cash balances in excess of government provided insurance. Management believes there was no significant concentration of credit risk with respect to these cash balances as of December 31, 2017 .
Depreciation, Depletion, and Amortization [Policy Text Block]		Depreciation and Amortization The purchase price of real estate acquired and costs related to development, construction, and property improvements are capitalized. Repairs and maintenance costs include all costs that do not extend the useful life of the real estate asset and are expensed as incurred. The Company considers the period of future benefit of an asset to determine the appropriate useful life. The Company anticipates the estimated useful lives of its assets by class to be generally as follows: Buildings 25-40 years Building Improvements 5-20 years Land Improvements 15-25 years Tenant Improvements Shorter of estimated useful life or remaining contractual lease term Tenant Origination and Absorption Cost Remaining contractual lease term In-place Lease Valuation Remaining contractual lease term with consideration as to below-market extension options for below-market leases If a lease is terminated or amended prior to its scheduled expiration, the Company will accelerate the remaining useful life of the unamortized lease-related costs.
Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy [Policy Text Block]		Impairment of Real Estate and Related Intangible Assets The Company continually monitors events and changes in circumstances that could indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, including credit ratings of all tenants to stay abreast of any material changes in credit quality. The Company monitors tenant credit by (1) reviewing the credit ratings of tenants (or their parent companies or lease guarantors) that are rated by nationally recognized rating agencies; (2) reviewing financial statements and related metrics and information that are publicly available or that are required to be provided pursuant to the lease; (3) monitoring news reports and press releases regarding the tenants (or their parent companies or lease guarantors), and their underlying business and industry; and (4) monitoring the timeliness of rent collections. When indicators of potential impairment are present that indicate that the carrying amounts of real estate and related intangible assets may not be recoverable, management assesses whether the carrying value of the assets will be recovered through the future undiscounted operating cash flows expected from the use of the assets and the eventual disposition. If, based on this analysis, the Company does not believe that it will be able to recover the carrying value of the asset, the Company will record an impairment charge to the extent the carrying value exceeds the net present value of the estimated future cash flows of the asset. Projections of expected future undiscounted cash flows require management to estimate future market rental income amounts subsequent to the expiration of current lease agreements, property operating expenses, discount rates, the number of months it takes to re-lease the property and the number of years the property is held for investment. As of December 31, 2017, the Company recorded an impairment provision of approximately $8.5 million related to the lease intangibles, building and land as it was determined that the carrying value of these assets would more than likely not be recoverable.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Line Items]
Property, Plant and Equipment [Table Text Block]	The Company anticipates the estimated useful lives of its assets by class to be generally as follows: Buildings 40 years Building Improvements 5-20 years Land Improvements 15-25 years Tenant Improvements Shorter of estimated useful life or remaining contractual lease term Tenant Origination and Absorption Cost Remaining contractual lease term In-place Lease Valuation Remaining contractual lease term with consideration as to below-market extension options for below-market leases
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment [Table Text Block]	The Company anticipates the estimated useful lives of its assets by class to be generally as follows: Buildings 25-40 years Building Improvements 5-20 years Land Improvements 15-25 years Tenant Improvements Shorter of estimated useful life or remaining contractual lease term Tenant Origination and Absorption Cost Remaining contractual lease term In-place Lease Valuation Remaining contractual lease term with consideration as to below-market extension options for below-market leases

Real Estate (Tables)

Real Estate (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Real Estate [Line Items]
Schedule of Aggregate purchase price of the acquisitions		The purchase price and other acquisition items for the properties acquired during the year ended December 31, 2017 are shown below: Paid to Advisor Property Location Tenant/Major Lessee Acquisition Date Purchase Price Approx. Square Feet Acquisition Fees and Reimbursable Expenses (1) Contingent Advisor Payment (2) Year of Lease Expiration Allstate Lone Tree, CO Allstate Insurance Company 1/31/2017 $ 14,750 (3) 70,300 $ 402 $ 273 2026 MISO Carmel, IN Midcontinent Independent System Operator, Inc. 5/15/2017 $ 28,600 133,400 $ 696 $ 529 2028 (1) Under the Original Advisory Agreement, the fee consisted of a 2.0% base acquisition fee and acquisition expense reimbursement for actual acquisition expenses incurred, estimated to be approximately 1.0% of acquisition value. (2) Under the Original Advisory Agreement, the Advisor was entitled to receive an acquisition fee in an amount up to 3.85% of the contract purchase price for each property the Company acquired. The acquisition fee consisted of a 2.0% base acquisition fee and up to an additional 1.85% contingent advisor payment (the “Contingent Advisor Payment”); provided, however, that $5.0 million of amounts advanced by the Advisor for dealer manager fees and organizational and offering expenses (the “Contingent Advisor Payment Holdback”) would be retained by the Company until the later of (a) the termination of the IPO, including any follow-on offerings where the Advisor provides up-front funding of offering fees, or (b) July 31, 2017, at which time such amount would be paid to the Advisor. On July 31, 2017, the Company paid to the Advisor the Contingent Advisor Payment Holdback of $5.0 million , which consisted of amounts previously advanced by the Advisor for dealer manager fees and organizational and offering expenses. (3) The purchase price for the Allstate property was $14.8 million , plus closing costs, less a credit in the amount of $0.4 million applied at closing.
Summary of purchase price allocation		The following summarizes the purchase price allocations for the properties acquired during the year ended December 31, 2017 : Property (1) Land Building and Improvements Tenant Origination and Absorption Cost In-Place Lease Valuation Above Market In-Place Lease Valuation (Below) Market Total Allstate $ 1,808 $ 9,071 $ 5,019 $ — $ (1,001 ) $ 14,897 MISO $ 3,104 $ 18,077 $ 7,937 $ 218 $ — $ 29,336 (1) The Company evaluated the transactions above under the clarified framework for determining whether an integrated set of assets and activities meets the definition of a business, pursuant to ASU No. 2017-01, Business Combinations, issued in January 2017, which the Company early-adopted effective October 1, 2016. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. Since the transactions above lacked a substantive process, the transactions did not meet the definition of a business and consequently were accounted for as asset acquisitions. The Company allocated the total consideration (including acquisition costs of approximately $1.2 million ) to the individual assets and liabilities acquired on a relative fair value basis.
Schedule of future minimum contractual rent payments	The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company's current leases have expirations ranging from 2021 to 2044. As of September 30, 2018 Remaining 2018 $ 19,311 2019 78,887 2020 80,492 2021 72,677 2022 73,538 Thereafter 528,803 Total $ 853,708	The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company’s current leases have expirations ranging from 2020 to 2044. As of December 31, 2017 2018 $ 71,662 2019 78,887 2020 80,492 2021 72,677 2022 73,538 Thereafter 528,803 Total $ 906,059
Schedule of in-place lease valuation and tenant origination and absorption cost	The Company allocated a portion of the acquired real estate asset value to in-place lease valuation and tenant origination and absorption cost. The in-place lease was measured against comparable leasing information and the present value of the difference between the contractual, in-place rent and the fair market rent was calculated using, as the discount rate, the capitalization rate utilized to compute the value of the real estate at acquisition. September 30, 2018 December 31, 2017 In-place lease valuation (above market) $ 4,046 $ 4,046 In-place lease valuation (above market), accumulated amortization (1,030 ) (752 ) Intangible assets, net $ 3,016 $ 3,294 In-place lease valuation (below market) $ (62,070 ) $ (62,070 ) In-place lease valuation (below market) - accumulated amortization 14,564 10,775 In-place lease valuation (below market), net $ (47,506 ) $ (51,295 ) Tenant origination and absorption cost $ 240,364 $ 240,364 Tenant origination and absorption cost - accumulated amortization (65,264 ) (47,165 ) Tenant origination and absorption cost, net $ 175,100 $ 193,199	The Company allocated a portion of the acquired real estate asset value to in-place lease valuation and tenant origination and absorption cost. The in-place lease was measured against comparable leasing information and the present value of the difference between the contractual, in-place rent and the fair market rent was calculated using, as the discount rate, the capitalization rate utilized to compute the value of the real estate at acquisition. The intangible assets are amortized over the remaining lease terms of the respective properties, which on a weighted-average basis, was approximately 10.3 and 11.4 years as of December 31, 2017 and December 31, 2016 , respectively. December 31, 2017 December 31, 2016 In-place lease valuation (above market) $ 4,046 $ 3,828 In-place lease valuation (above market), accumulated amortization (752 ) (300 ) Intangible assets, net $ 3,294 $ 3,528 In-place lease valuation (below market) $ (62,070 ) $ (61,069 ) In-place lease valuation (below market) - accumulated amortization 10,775 5,750 In-place lease valuation (below market), net $ (51,295 ) $ (55,319 ) Tenant origination and absorption cost $ 240,364 $ 227,407 Tenant origination and absorption cost - accumulated amortization (47,165 ) (23,409 ) Tenant origination and absorption cost, net $ 193,199 $ 203,998
Schedule of estimated annual amortization (income) expense		The amortization of the intangible assets and other leasing costs for the respective periods is as follows: Amortization (income) expense for the year ended December 31, 2017 2016 2015 In-place lease valuation $ (4,573 ) $ (3,592 ) $ (1,858 ) Tenant origination and absorption cost $ 23,756 $ 16,264 $ 7,145
Estimated annual amortization (income) expense, in-place lease valuation	The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, and tenant origination and absorption costs as of September 30, 2018 for the next five years : Year In-Place Lease Valuation Tenant Origination and Absorption Costs Remaining 2018 $ (1,170 ) $ 6,033 2019 $ (4,695 ) $ 24,198 2020 $ (4,695 ) $ 24,198 2021 $ (3,799 ) $ 19,715 2022 $ (3,799 ) $ 19,597	The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, and tenant origination and absorption costs as of December 31, 2017 for the next five years: Year In-Place Lease Valuation Tenant Origination and Absorption Costs 2018 $ (4,695 ) $ 24,198 2019 $ (4,695 ) $ 24,198 2020 $ (4,695 ) $ 24,198 2021 $ (3,799 ) $ 19,715 2022 $ (3,799 ) $ 19,597
Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Schedule of Aggregate purchase price of the acquisitions	The purchase price and other acquisition items for the properties acquired during the nine months ended September 30, 2018 are shown below: Property Location Tenant/Major Lessee Acquisition Date Purchase Price Approx. Square Feet Acquisition Fees and Expenses (1) Year of Lease Expiration Quaker Lakeland, Florida Quaker Sales and Distribution, Inc. 3/13/2018 $ 59,600 605,400 $ 1,777 2028 McKesson Scottsdale, Arizona McKesson Corporation 4/10/2018 $ 67,000 271,100 $ 2,139 2028 Shaw Wentworth, Georgia Shaw Industries, Inc. 5/3/2018 $ 56,526 1,001,500 $ 1,782 2033 (1) The Advisor is entitled to receive acquisition fees equal to 2.5% and acquisition expense reimbursement of up to 0.5% of the contract purchase price for each acquisition. In addition, the Company incurred third-party costs associated with the three acquisitions.	The purchase price and other acquisition items for the property acquired during the year ended December 31, 2017 are shown below: Property Location Tenant/Major Lessee Acquisition Date Purchase Price Approx. Square Feet Acquisition Fees Paid to the Advisor (1) Year of Lease Expiration LPL Fort Mill, SC LPL Holdings, Inc. 11/30/2017 $ 130,000 451,600 $ 3,791 2036 (1) The Advisor is entitled to receive acquisition fees equal to 2.5% and acquisition expense reimbursement of up to 0.5% of the contract purchase price for each acquisition.
Summary of purchase price allocation		The following summarizes the purchase price allocation of the LPL property acquired during the year ended December 31, 2017 : Property Land Building and improvements Tenant origination and absorption costs In-place lease valuation - above market Total LPL (1) $ 5,886 $ 108,000 $ 19,859 $ 383 $ 134,128 (1) The Company evaluated the transactions above under the clarified framework for determining whether an integrated set of assets and activities meets the definition of a business, pursuant to ASU No. 2017-01, Business Combinations, issued in January 2017, which the Company early-adopted effective January 1, 2017. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. Since the transaction above lacked a substantive process, the transaction did not meet the definition of a business and consequently was accounted for as asset acquisition. The Company allocated the total consideration (including acquisition costs of approximately $4.1 million ) to the individual assets and liabilities acquired on a relative fair value basis.
Schedule of future minimum contractual rent payments	The following summarizes the purchase price allocations of the properties acquired during the nine months ended September 30, 2018 : Property (1) Land Building and improvements Tenant origination and absorption costs In-place lease valuation - above (below) market Receivable- Ground Lease Payable- Ground Lease Payments Total Quaker $ 5,433 $ 50,953 $ 4,387 $ (502 ) $ — $ — $ 60,271 McKesson $ 312 $ 45,109 $ 24,652 $ (933 ) $ — $ — $ 69,140 Shaw $ 5,465 $ 48,820 $ 8,297 $ (4,273 ) $ 2,008 $ (2,008 ) $ 58,309 (1) The Company evaluated the transactions above under the clarified framework for determining whether an integrated set of assets and activities meets the definition of a business, pursuant to ASU No. 2017-01, Business Combinations, issued in January 2017, which the Company early-adopted effective January 1, 2017. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. Since the transactions above lacked a substantive process, the transactions did not meet the definition of a business and consequently were accounted for as asset acquisitions. The Company allocated the total consideration (including acquisition costs of approximately $5.7 million ) to the individual assets and liabilities acquired on a relative fair value basis. The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company's current leases have expirations ranging from 2018 to 2036. As of September 30, 2018 Remaining 2018 $ 61,164 2019 226,557 2020 204,640 2021 191,182 2022 182,708 Thereafter 803,849 Total $ 1,670,100	The future minimum contractual rent payments pursuant to the current lease terms are shown in the table below. The Company’s current leases have expirations ranging from 2018 to 2036. As of December 31, 2017 2018 $ 231,620 2019 210,449 2020 188,653 2021 174,053 2022 164,494 Thereafter 664,226 Total $ 1,633,495
Schedule of in-place lease valuation and tenant origination and absorption cost	The Company allocated a portion of the acquired and contributed real estate asset value to in-place lease valuation and tenant origination and absorption cost, net of the write-off of intangibles, as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 In-place lease valuation (above market) $ 42,736 $ 42,736 In-place lease valuation (above market) - accumulated amortization (31,065 ) (26,613 ) In-place lease valuation (above market), net 11,671 16,123 Ground leasehold interest (below market) 2,254 2,255 Ground leasehold interest (below market) - accumulated amortization (129 ) (109 ) Ground leasehold interest (below market), net 2,125 2,146 Intangible assets, net $ 13,796 $ 18,269 In-place lease valuation (below market) $ (55,482 ) $ (49,774 ) In-place lease valuation (below market) - accumulated amortization 30,779 26,193 In-place lease valuation (below market), net $ (24,703 ) $ (23,581 ) Tenant origination and absorption cost $ 532,207 $ 494,871 Tenant origination and absorption cost - accumulated amortization (284,763 ) (242,108 ) Tenant origination and absorption cost, net $ 247,444 $ 252,763	The Company allocated a portion of the acquired and contributed real estate asset value to in-place lease valuation and tenant origination and absorption cost, net of the write-off of intangibles for the years ended December 31, 2017 and 2016 . In-place leases were measured against comparable leasing information and the present value of the difference between the contractual, in-place rent, and the fair market rent was calculated using, as the discount rate, the capitalization rate utilized to compute the value of the real estate at acquisition or contribution. December 31, 2017 2016 In-place lease valuation (above market) $ 43,826 $ 47,419 In-place lease valuation (above market) - accumulated amortization (27,703 ) (20,543 ) In-place lease valuation (above market), net 16,123 26,876 Ground leasehold interest (below market) 2,255 2,254 Ground leasehold interest (below market) - accumulated amortization (109 ) (82 ) Ground leasehold interest (below market), net 2,146 2,172 Intangible assets, net $ 18,269 $ 29,048 In-place lease valuation (below market) $ (49,774 ) $ (51,966 ) In-place lease valuation (below market) - accumulated amortization 26,193 20,330 In-place lease valuation (below market), net $ (23,581 ) $ (31,636 ) Tenant origination and absorption cost $ 495,364 $ 541,646 Tenant origination and absorption cost - accumulated amortization (242,601 ) (197,173 ) Tenant origination and absorption cost, net $ 252,763 $ 344,473
Schedule of estimated annual amortization (income) expense	The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, net, tenant origination and absorption costs, ground leasehold improvements, and other leasing costs as of September 30, 2018 for the next five years: Year In-place lease valuation, net Tenant origination and absorption costs Ground leasehold improvements Other leasing costs Remaining 2018 $ (386 ) $ 11,150 $ 21 $ 2,389 2019 $ (2,464 ) $ 38,096 $ 21 $ 4,765 2020 $ (936 ) $ 29,867 $ 21 $ 4,712 2021 $ (717 ) $ 25,170 $ 21 $ 4,830 2022 $ (1,058 ) $ 22,938 $ 21 $ 4,818	The amortization of the intangible assets and other leasing costs for the respective periods is as follows: Amortization (income) expense for the year ended December 31, 2017 2016 2015 In-place lease valuation, net $ 1,689 $ 3,287 $ (3,785 ) Tenant origination and absorption cost $ 59,046 $ 72,912 $ 69,099 Ground leasehold amortization (below market) $ 27 $ 28 $ 28 Other leasing costs amortization $ 1,527 $ 1,202 $ 301
Restrictions on cash and cash equivalents	In conjunction with acquisition of certain assets, as required by certain lease provisions or certain lenders in conjunction with an acquisition or debt financing, or credits received by the seller of certain assets, the Company assumed or funded reserves for specific property improvements and deferred maintenance, re-leasing costs, and taxes and insurance, which are included on the consolidated balance sheets as restricted cash. Additionally, an ongoing replacement reserve is funded by certain tenants pursuant to each tenant’s respective lease as follows: Balance as of September 30, 2018 December 31, 2017 Cash reserves $ 20,619 $ 17,034 Midland mortgage loan restricted lockbox 1,746 2,158 1031 Exchange Funds (1) — 154,940 Total $ 22,365 $ 174,132 (1) Section 1031 of the Internal Revenue Code of 1986, as amended ("1031 Exchanges"). Represents cash proceeds from a disposition that are temporarily held at the qualified intermediary for purposes of facilitating potential Section 1031 Exchanges. The Company's three acquisitions during the six months ended June 30, 2018 completed the 1031 Exchange.	Additionally, an ongoing replacement reserve is funded by certain tenants pursuant to each tenant’s respective lease as follows: Balance as of December 31, 2016 Additions Deductions Balance as of December 31, 2017 Tenant improvement reserves (1) $ 9,238 $ 5,468 $ (1,071 ) $ 13,635 Midland mortgage loan repairs reserves (2) 67 323 — 390 Real estate tax reserve (3) 1,645 3,344 (2,892 ) 2,097 Property insurance reserve (Emporia Partners) (3) 257 467 (499 ) 225 Rent Abatement Reserve — 731 (390 ) 341 Restricted deposits/Leasing commission reserve 745 4 (404 ) 345 Midland mortgage loan restricted lockbox (4) 1,468 2,158 (1,468 ) 2,158 Holdback Escrow (5) — 77,275 (77,275 ) — 1031 Exchange Funds (6) — 286,711 (131,771 ) 154,940 Total $ 13,420 $ 376,481 $ (215,770 ) $ 174,131 (1) Represents tenant improvement reserves held by the lenders. (2) Represents a deferred maintenance reserve funded by the Company as part of the refinancing that occurred on February 28, 2013, whereby certain properties became collateral for the Midland mortgage loan. (3) Represents real estate tax and insurance reserves which are funded monthly and held by the lenders. Funds are requested for disbursement as real estate tax and insurance premium payments are made. (4) As part of the terms of the Midland mortgage loan, rent collections from the eight properties which serve as collateral thereunder are received in a designated cash collateral account which is controlled by the lender until the designated payment date, as defined in the loan agreement, and the excess cash is transferred to the operating account. (5) Represents initial funds held back related to the Bank of America Loan, which were released on October 25, 2017 and October 26, 2017. (6) Represents cash proceeds from a disposition that are temporarily held at the qualified intermediary for purposes of facilitating potential Section 1031 Exchanges.
Major components of assets and liabilities related to the real estate held for sale	The following summary presents the major components of assets and liabilities related to the real estate held for sale as of the nine months ended September 30, 2018 and year ended December 31, 2017 : Balance as of September 30, 2018 December 31, 2017 Land $ 589 $ 589 Building and improvements 2,493 2,493 Tenant origination and absorption cost 493 493 Total real estate 3,575 3,575 Less: accumulated depreciation and amortization (868 ) (794 ) Total real estate, net 2,707 2,781 Other assets 4 178 Total assets $ 2,711 $ 2,959 Accrued expenses and other liabilities $ 288 $ 527 Due to affiliates 5 10 Total liabilities $ 293 $ 537
Estimated annual amortization (income) expense, in-place lease valuation		The following table sets forth the estimated annual amortization (income) expense for in-place lease valuation, net, tenant origination and absorption costs, ground leasehold improvements, and other leasing costs as of December 31, 2017 for the next five years: Year In-place lease valuation, net Tenant origination and absorption costs Ground leasehold improvements Other leasing costs 2018 $ (1,018 ) $ 51,363 $ 27 $ 1,768 2019 $ (1,856 ) $ 42,721 $ 27 $ 1,782 2020 $ (770 ) $ 33,302 $ 27 $ 1,757 2021 $ (630 ) $ 28,724 $ 27 $ 1,704 2022 $ (1,007 ) $ 24,918 $ 27 $ 1,674

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Griffin Capital Essential Asset REIT, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of the investment	As of December 31, 2017 , the balance of the investment is shown below: Digital Realty Joint Venture Balance as of December 31, 2016 $ 46,313 Other comprehensive income 465 Net loss (2,065 ) Distributions (7,599 ) Balance as of December 31, 2017 $ 37,114

Debt (Tables)

Debt (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Schedule of debt	As of September 30, 2018 and December 31, 2017 , the Company's debt and related deferred financing costs consisted of the following: September 30, 2018 December 31, 2017 Contractual Interest Rate (1) Payment Type Loan Maturity Effective Interest Rate (2) BofA/KeyBank Loan $ 250,000 $ — 4.32% Interest Only May 2028 4.36% AIG Loan 126,970 126,970 4.15% Interest Only (3) November 2025 4.22% Total Mortgage Debt 376,970 126,970 Term Loan 113,000 — LIBOR + 1.25% (4) Interest Only June 2023 3.58% Revolving Credit Facility 85 357,758 LIBOR + 1.30% (4)(5) Interest Only June 2023 (6) 3.65% Total Debt 490,055 484,728 Unamortized deferred financing costs (8,482 ) (2,880 ) Total Debt, net $ 481,573 $ 481,848 (1) Including the effect of one interest rate swap agreement with a total notional amount of $100.0 million , the weighted average interest rate as of September 30, 2018 was approximately 3.81% for the Company's fixed-rate and variable-rate debt combined. (2) Includes the effect of amortization of deferred financing costs. (3) The AIG Loan (as defined below) requires monthly payments of interest only, at a fixed rate, for the first five years and fixed monthly payments of principal and interest thereafter. (4) The LIBOR as of September 30, 2018 was 2.11% . (5) As discussed below, the Company entered into an amended and restated credit agreement in June 2018. The contractual interest rate on the original revolving credit facility was LIBOR + 1.50% as of March 31, 2018. (6) The Revolving Credit Facility (as defined below) has an initial term of four years, maturing on June 28, 2022, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below. (7)	As of December 31, 2017 and 2016 , the Company’s debt and related deferred financing costs consisted of the following: December 31, 2017 December 31, 2016 Contractual Interest Rate (1) Payment Type Loan Maturity Effective Interest Rate (4) Revolving Credit Facility $ 357,758 $ 333,458 2.87% Interest Only December 2019 (2) 3.32% AIG Loan 126,970 126,970 4.15% Interest Only (3) November 2025 4.22% Total Debt 484,728 460,428 Unamortized deferred financing costs (2,880 ) (3,956 ) Total Debt, net $ 481,848 $ 456,472 (1) The 2.87% contractual interest rate is based on a 360 -day year, pursuant to the Revolving Credit Facility. The 2.92% weighted-average interest rate is based on a 365 -day year. As discussed below, the interest rate on the Revolving Credit Facility (as defined below) is a one-month LIBO Rate + 1.50% . As of December 31, 2017 , the LIBO Rate was 1.57% . Including the effect of interest rate swap agreements with a total notional amount of $200.0 million , the weighted average interest rate as of December 31, 2017 was approximately 3.13% for the Company’s fixed-rate and variable-rate debt combined. (2) The Revolving Credit Facility has an initial term of four years, maturing on December 12, 2018, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below. (3) The AIG Loan (as defined below) requires monthly payments of interest only, at a fixed rate, for the first five years and fixed monthly payments of principal and interest thereafter. (4) Reflects the effective interest rate at December 31, 2017 and includes the effect of amortization of deferred financing costs.
Schedule of Maturities of Long-term Debt [Table Text Block]		The following summarizes the future principal repayments of all loans as of December 31, 2017 per the loan terms discussed above: December 31, 2017 2018 $ — 2019 357,758 2020 — 2021 2,178 2022 2,271 Thereafter 122,521 Total principal 484,728 Unamortized deferred loan costs (2,880 ) Total $ 481,848
Griffin Capital Essential Asset REIT, Inc. [Member]
Debt Instrument [Line Items]
Schedule of debt	As of September 30, 2018 and December 31, 2017 , the Company’s debt consisted of the following: September 30, 2018 December 31, 2017 Contractual Interest Rate (1) Loan Maturity Effective Interest Rate (2) TW Telecom loan (3) $ — $ 19,169 — — —% HealthSpring loan 21,340 21,694 4.18% April 2023 4.60% Midland loan 102,753 104,197 3.94% April 2023 4.12% Emporia Partners loan 2,662 2,978 5.88% September 2023 5.96% Samsonite loan 22,309 22,961 6.08% September 2023 5.16% Highway 94 loan 16,714 17,352 3.75% August 2024 4.65% Bank of America loan 375,000 375,000 3.77% October 2027 3.91% AIG loan 107,998 109,275 4.96% February 2029 5.07% Total Mortgage Debt 648,776 672,626 Term Loan 715,000 715,000 LIBOR+1.40% (4) July 2020 3.89% Revolver Loan — 10,153 LIBOR +1.45% (4) July 2020 (4) 3.77% Total Debt 1,363,776 1,397,779 Unamortized Deferred Financing Costs and Discounts, net (9,426 ) (11,695 ) Total Debt, net $ 1,354,350 $ 1,386,084 (1) Including the effect of one interest rate swap agreement with a total notional amount of $425.0 million , the weighted average interest rate as of September 30, 2018 was 3.70% for the Company’s fixed-rate and variable-rate debt combined and 3.75% for the Company’s fixed-rate debt only. (2) Reflects the effective interest rate as of September 30, 2018 and includes the effect of amortization of discounts/premiums and deferred financing costs. (3) In March 2018, the Company, through the Operating Partnership, paid off the remaining balance of the TW Telecom loan. (4) The LIBO rate as of September 30, 2018 was 2.11% .The Revolver Loan has an initial term of four years, maturing on July 20, 2019, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below.	As of December 31, 2017 and December 31, 2016, the Company’s debt consisted of the following: December 31, 2017 December 31, 2016 Contractual Interest Rate (1) Loan Maturity Effective Interest Rate (2) Plainfield loan $ — $ 18,932 — — — Emporia Partners loan 2,978 3,377 5.88% September 2023 5.96% Ace Hardware loan — 22,922 — — — Highway 94 loan 17,352 18,175 3.75% August 2024 4.63% Samsonite loan 22,961 23,786 6.08% September 2023 5.22% HealthSpring loan 21,694 22,149 4.18% April 2023 4.59% Midland loan 104,197 105,600 3.94% April 2023 4.08% AIG loan 109,275 110,640 4.96% February 2029 5.07% TW Telecom loan 19,169 20,353 LIBO Rate +2.45% (3) August 2019 4.04% Bank of America loan 375,000 — 3.77% August 2027 3.90% Total Mortgage Debt 672,626 345,934 Term Loan 715,000 715,000 LIBO Rate +1.40% (3) July 2020 3.19% Revolver Loan 10,153 397,409 LIBO Rate +1.45% (3) July 2020 (4) 3.79% Total Debt 1,397,779 1,458,343 Unamortized Deferred Financing Costs and Discounts, net (11,695 ) (10,808 ) Total Debt, net $ 1,386,084 $ 1,447,535 (1) Including the effect of interest rate swap agreements with a total notional amount of $725.0 million , the weighted average interest rate as of December 31, 2017 was 3.53% for the Company’s fixed-rate and variable-rate debt combined and 3.54% for the Company’s fixed-rate debt only. (2) Reflects the effective interest rate as of December 31, 2017 and includes the effect of amortization of discounts/premiums and deferred financing costs. (3) The LIBO Rate as of December 31, 2017 was 1.56% . (4) The Revolver Loan has an initial term of four years , maturing on July 20, 2019, and may be extended for a one -year period if certain conditions are met and upon payment of an extension fee. See discussion below.
Schedule of Maturities of Long-term Debt [Table Text Block]		The following summarizes the future principal repayments of all loans as of December 31, 2017 per the loan terms discussed above: December 31, 2017 2018 $ 7,132 2019 24,879 2020 732,034 2021 7,211 2022 7,556 Thereafter 618,967 Total principal 1,397,779 Unamortized debt premium/(discount) (281 ) Unamortized deferred loan costs (11,414 ) Total $ 1,386,084

Interest Rate Contracts (Tables

Interest Rate Contracts (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Summary of interest rate swaps	The following table sets forth a summary of the interest rate swaps at September 30, 2018 and December 31, 2017 : Fair Value (1) Derivative Instruments Effective Date Maturity Date/ Termination Interest Strike Rate September 30, 2018 December 31, 2017 Assets Interest Rate Swap 4/1/2016 12/12/2018 0.74% $ 310 $ 967 Interest Rate Swap (terminated on April 30, 2018) 11/1/2017 4/30/2018 1.50% — 65 $ 310 $ 1,032 (1) The Company records all derivative instruments on a gross basis on the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of September 30, 2018 , the Company's derivative was in an asset position, and as such, the fair value is included in the line item "Other Assets, net" on the consolidated balance sheet.	The following table sets forth a summary of the interest rate swaps at December 31, 2017 and December 31, 2016 : Fair Value (1) Current Effective Notional Amount (2) Derivative Instrument Effective Date Maturity Date Interest Strike Rate December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Assets Interest Rate Swap 4/1/2016 12/12/2018 0.74% $ 967 $ 996 $ 100,000 $ 100,000 Interest Rate Swap (3) 11/1/2017 7/1/2018 1.50% 65 — 100,000 — Total $ 1,032 $ 996 $ 200,000 $ 100,000 (1) The Company records all derivative instruments on a gross basis on the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of December 31, 2017 , the Company’s derivatives were in asset positions, and as such, the fair value is included in the line item “Other Assets, net” on the consolidated balance sheet. (2) Represents the notional amount of swap that was effective as of the balance sheet date of December 31, 2017 and December 31, 2016 . (3) Effective as of November 1, 2017, Griffin Capital Essential Asset Operating Partnership, L.P, an affiliated party novated a $100 million interest rate swap agreement with an expiration date of June 1, 2018 to the Company’s Operating Partnership. The Company paid approximately nine thousand dollars, which approximated fair value.
Impact of interest rate swap on consolidated statements of operation	The following table sets forth the impact of the interest rate swaps on the consolidated financial statements for the nine months ended September 30, 2018 and 2017 : Nine Months Ended September 30, 2018 2017 Interest Rate Swaps in Cash Flow Hedging Relationship: Amount of (gain) recognized in AOCI on derivatives $ (281 ) $ (190 ) Amount of gain reclassified from AOCI into earnings under “Interest expense” $ 922 $ 207 Total interest expense presented in the consolidated statement of operations in which the effects of cash flow hedges are recorded $ 14,775 $ 11,445	The following table sets forth the impact of the interest rate swaps on the consolidated financial statements for the periods presented: Year Ended December 31, 2017 2016 Interest Rate Swaps in Cash Flow Hedging Relationship: Amount of loss recognized in AOCI on derivative (effective portion) $ 428 $ 662 Amount of (gain) loss reclassified from AOCI into earnings under “Interest expense” (effective portion) $ (319 ) $ 179 Amount of (loss) gain recognized in earnings under “Interest expense” (ineffective portion and amount excluded from effectiveness testing) $ (80 ) $ 155
Griffin Capital Essential Asset REIT, Inc. [Member]
Derivative [Line Items]
Summary of interest rate swaps		The following table sets forth a summary of the interest rate swaps at December 31, 2017 and December 31, 2016 : Fair Value (1) Current Notional Amount (2) December 31, Derivative Instrument Effective Date Maturity Date Interest Strike Rate 2017 2016 2017 2016 Assets/(Liabilities): Interest Rate Swap 7/9/2015 7/1/2020 1.69% $ 3,255 $ (1,630 ) $ 425 $ 425 Interest Rate Swap 1/1/2016 7/1/2018 1.32% 458 (907 ) 300 300 Interest Rate Swap (3) 7/1/2016 7/1/2018 1.50% — (564 ) — 100 Total $ 3,713 $ (3,101 ) $ 725 $ 825 (1) The Company records all derivative instruments on a gross basis in the consolidated balance sheets, and accordingly, there are no offsetting amounts that net assets against liabilities. As of December 31, 2017 , derivatives in a asset/liability position are included in the line item “Other assets/Accrued expenses and other liabilities,” respectively, in the consolidated balance sheets at fair value. (2) Represents the notional amount of swaps that are effective as of the balance sheet date of December 31, 2017 and 2016 . (3) Effective as of November 1, 2017, the Operating Partnership novated the $100 million interest rate swap agreement to an affiliated party, Griffin Capital Essential Asset Operating Partnership II, L.P., for approximately nine-thousand dollars. At the date of novation, the Company accelerated the reclassification of amounts in other comprehensive income to earnings as a result of the hedged forecasted transactions becoming probable not to occur. The novation involved cash consideration that reflected the termination value of the trade at the time of novation.
Impact of interest rate swap on consolidated statements of operation		The following table sets forth the impact of the interest rate swap on the consolidated statements of operations for the periods presented: Year Ended December 31, 2017 2016 Interest Rate Swap in Cash Flow Hedging Relationship: Amount of gain (loss) recognized in AOCI on derivatives (effective portion) $ 3,035 $ (6,253 ) Amount of gain (loss) reclassified from AOCI into earnings under “Interest expense” (effective portion) $ 3,856 $ (8,286 ) Amount of gain (loss) recognized in earnings under “Interest expense” (ineffective portion and amount excluded from effectiveness testing) $ (19 ) $ (70 )

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Accounts Payable And Accrued Liabilities [Line Items]
Schedule of accrued expenses and other liabilities	Accrued expenses and other liabilities consisted of the following as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 Prepaid rent $ 4,866 $ 4,304 Leasing commission payable 1,900 3,783 Accrued property taxes 3,633 3,490 Interest expense payable 2,661 3,013 Redemptions payable 6,671 2,181 Other liabilities 2,034 3,132 Total $ 21,765 $ 19,903	Accrued expenses and other liabilities consisted of the following as of December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 Prepaid rent $ 4,304 $ 9,484 Leasing commission payable 3,783 3,783 Accrued property taxes 3,490 2,678 Interest expense payable 3,013 1,716 Other liabilities 5,313 3,866 Total $ 19,903 $ 21,527
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Schedule of accrued expenses and other liabilities	Accrued expenses and other liabilities consisted of the following as of September 30, 2018 and December 31, 2017 : September 30, 2018 December 31, 2017 Prepaid rent $ 14,543 $ 16,138 Real estate taxes payable 25,666 21,087 Interest payable 9,270 7,924 Other liabilities 25,455 18,457 Total $ 74,934 $ 63,606	Accrued expenses and other liabilities consisted of the following as of December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 Prepaid rent $ 16,312 $ 16,799 Real estate taxes payable 21,317 24,585 Interest payable 7,924 7,606 Interest rate swap liability — 3,101 Other liabilities 18,580 12,914 Total $ 64,133 $ 65,005

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of assets and liabilities measure at fair value on a recurring basis	The following tables set forth the assets that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2018 : Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Interest Rate Swaps at: September 30, 2018 $ 310 $ — $ 310 $ — December 31, 2017 $ 1,032 $ — $ 1,032 $ —	The following tables set forth the assets/(liabilities) that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2017 and 2016 : Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Interest Rate Swaps at: December 31, 2017 $ 1,032 $ — $ 1,032 $ — December 31, 2016 $ 996 $ — $ 996 $ —
Schedule of carrying values and estimated fair values of financial instruments	The Company determined that the mortgage loan valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt, and there were no transfers into and out of fair value measurement levels during the nine months ended September 30, 2018 and for the year ended December 31, 2017 . September 30, 2018 December 31, 2017 Fair Value Carrying Value (1) Fair Value Carrying Value (1) AIG Loan $ 119,338 $ 126,970 $ 122,928 $ 126,970 (1) The carrying value of the AIG Loan does not include deferred financing costs as of September 30, 2018 and December 31, 2017 . See Note 4, Debt , for details.	The Company determined that the mortgage loan valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt, and there were no transfers into and out of fair value measurement levels during the years ended December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Fair Value Carrying Value (1) Fair Value Carrying Value (1) AIG Loan $ 122,928 $ 126,970 $ 120,322 $ 126,970 (1) The carrying value of the AIG Loan does not include deferred financing costs as of December 31, 2017 and 2016 . See Note 4, Debt , for details.
Griffin Capital Essential Asset REIT, Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of assets and liabilities measure at fair value on a recurring basis	The following tables set forth the assets that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2018 and December 31, 2017 : Assets/(Liabilities) Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs September 30, 2018 Interest Rate Swap Asset $ 10,892 $ — $ 10,892 $ — December 31, 2017 Interest Rate Swap Asset $ 3,713 $ — $ 3,713 $ —	The following tables set forth the assets and liabilities that the Company measures at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2017 and 2016 : Assets/(Liabilities) Total Fair Value Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs December 31, 2017 Interest Rate Swap Asset $ 3,713 $ — $ 3,713 $ — December 31, 2016 Interest Rate Swap Liability $ (3,101 ) $ — $ (3,101 ) $ —
Schedule of carrying values and estimated fair values of financial instruments	The Company determined that the mortgage debt valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt. September 30, 2018 December 31, 2017 Fair Value Carrying Value (1) Fair Value Carrying Value (1) Highway 94 loan $ 15,637 $ 16,714 $ 16,484 $ 17,352 BofA loan $ 361,602 $ 375,000 $ 377,289 $ 375,000 (1) The carrying values do not include the debt premium/(discount) or deferred financing costs as of September 30, 2018 and December 31, 2017 . See Note 5, Debt , for details.	The Company determined that the mortgage debt valuation in its entirety is classified in Level 2 of the fair value hierarchy, as the fair value is based on current pricing for debt with similar terms as the in-place debt. December 31, 2017 December 31, 2016 Fair Value Carrying Value (1) Fair Value Carrying Value (1) AIG loan $ 113,715 $ 109,275 $ 113,052 $ 110,640 Highway 94 loan 16,484 17,352 17,073 18,175 Samsonite loan 23,851 22,961 24,349 23,786 (1) The carrying values do not include the debt premium/(discount) or deferred financing costs as of December 31, 2017 and 2016 . See Note 5, Debt , for details.

Equity (Tables)

Equity (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Schedule of Stock by Class [Table Text Block]	The following table summarizes shares issued and gross proceeds received for each share class as of September 30, 2018 and outstanding shares as of September 30, 2018 and December 31, 2017 : Class T Class S Class D Class I Class A Class AA Class AAA Total Gross proceeds from primary portion of offerings $ 2,245 $ 3 $ 182 $ 7,538 $ 240,780 $ 474,858 $ 8,381 $ 733,987 Gross proceeds from DRP $ 16 $ — $ 2 $ 158 $ 25,328 $ 32,369 $ 503 $ 58,376 Shares issued in primary portion of offerings 224,647 264 18,921 786,573 24,199,764 47,562,870 901,225 73,694,264 DRP shares issued 1,650 13 236 16,496 2,669,097 3,412,273 53,014 6,152,779 Stock distribution shares issued — — — — 263,642 300,166 4,677 568,485 Restricted stock issued — — — — — — 36,000 36,000 Total redemptions — — — — (1,351,178 ) (1,434,491 ) (5,593 ) (2,791,262 ) Total shares outstanding as of September 30, 2018 226,297 277 19,157 803,069 25,781,325 49,840,818 989,323 77,660,266 Total shares outstanding as of December 31, 2017 4,148 268 268 267,476 25,995,943 49,942,471 964,709 77,175,283	The following table summarizes shares issued and gross proceeds received for each share class as of December 31, 2017 and outstanding shares as of December 31, 2017 and 2016 : Class T S D I A AA AAA Total Gross proceeds from primary portion of offerings $ 41 $ 3 $ 3 $ 2,493 $ 240,780 $ 474,858 $ 8,379 $ 726,557 Gross proceeds from DRP $ — $ — $ — $ 41 $ 19,773 $ 21,828 $ 312 $ 41,954 Shares issued in primary portion of offerings 4,144 264 264 263,200 24,199,760 47,562,870 901,225 72,931,727 DRP shares issued 4 4 4 4,276 2,089,748 2,313,170 33,308 4,440,514 Stock distribution shares issued — — — — 263,641 300,166 4,676 568,483 Restricted stock units issued — — — — — — 25,500 25,500 Total redemptions — — — — (557,206 ) (233,735 ) — (790,941 ) Total shares outstanding as of 12/31/2017 4,148 268 268 267,476 25,995,943 49,942,471 964,709 77,175,283 Total shares outstanding as of 12/31/2016 — — — — 25,562,982 44,595,631 781,034 70,939,647
Share Redemption Price [Table Text Block]	During the three and nine months ended September 30, 2018 and 2017 , the Company redeemed shares of its outstanding common stock under the IPO Share Redemption Program as follows: Three Months Ended September 30, Nine Months Ended September 30, Period 2018 2017 2018 2017 Shares of common stock redeemed 585,525 (1) 146,083 1,306,834 413,842 Weighted average price per share $ 9.65 $ 9.06 $ 9.36 $ 9.18 (1) Second quarter requests redeemed in the third quarter. During the three and nine months ended September 30, 2018 and 2017 , the Company redeemed shares of its outstanding common stock under the New Share Redemption Program as follows: Three Months Ended September 30, Nine Months Ended September 30, Period 2018 2017 2018 2017 Shares of common stock redeemed 693,487 — 693,487 — Weighted average price per share $ 9.62 — $ 9.62 —	The redemption price per IPO Share is expected to be the redemption rate set forth in the following table which is based upon the number of years the stock is held: Number Years Held Redemption Price per Share Less than 1 year No Redemption Allowed After one year from the purchase date 90.0% of the Redemption Amount (as defined below) After two years from the purchase date 95.0% of the Redemption Amount After three years from the purchase date 97.5% of the Redemption Amount After four years from the purchase date 100.0% of the Redemption Amount
Organizational and Offering Costs Incurred [Table Text Block]	Organizational and offering costs incurred as of September 30, 2018 , including those incurred by the Company and due to the Advisor, for the Follow-On Offering are as follows: September 30, 2018 Cumulative offering costs $ 2,806 Cumulative organizational costs $ 510 Organizational and offering costs advanced by the Advisor $ 1,998 Organizational and offering costs paid by the Company 1,318 Adjustment to organizational and offering costs pursuant to the limitation: Costs in excess of limit (1,820 ) Organizational and offering costs incurred $ 1,496	Organizational and offering costs incurred as of December 31, 2017 , including those incurred by the Company and due to the Advisor, for the follow-on offering are as follows: December 31, 2017 Cumulative offering costs $ 1,698 Cumulative organizational costs $ 359 Organizational and offering costs advanced by the Advisor $ 1,226 Organizational and offering costs paid by the Company 831 Adjustment to organizational and offering costs pursuant to the limitation: Reduction in due to affiliates (999 ) Due from affiliates (677 ) Net due to Advisor $ 381
Schedule of share redemption activity		During the years ended ended December 31, 2017 and 2016 , the Company redeemed shares of its outstanding common stock as follows: Year Ended December 31, Period 2017 2016 Shares of common stock redeemed 623,499 167,442 Weighted average price per share $ 9.21 $ 9.72
Schedule of distributions paid		The following unaudited table summarizes the federal income tax treatment for all distributions per share for the years ended December 31, 2017 , 2016 and 2015 reported for federal tax purposes and serves as a designation of capital gain distributions, if applicable, pursuant to Section 857(b)(3)(c) of the Code and Treasury Regulation § 1.857-6(e). Year Ended December 31, 2017 2016 2015 Ordinary income $ 0.04 7.90 % $ 0.31 57.10 % $ 0.21 38.60 % Return of capital 0.51 92.10 % 0.24 42.90 % 0.34 61.40 % Total distributions paid $ 0.55 100.00 % $ 0.55 100.00 % $ 0.55 100.00 %
Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Schedule of share redemption activity	The following table summarizes share redemption activity during the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Shares of common stock redeemed 1,311,582 2,936,150 8,013,521 6,155,290 Weighted average price per share $ 9.63 $ 9.97 $ 9.60 $ 9.98	The following table summarizes share redemption activity during the years ended December 31, 2017 and 2016 : Year Ended December 31, 2017 2016 Shares of common stock redeemed 9,931,245 4,164,955 Weighted average price per share $ 9.96 $ 9.95
Schedule of distributions paid		The following unaudited table summarizes the federal income tax treatment for all distributions per share for the years ended December 31, 2017, 2016, and 2015 reported for federal tax purposes and serves as a designation of capital gain distributions, if applicable, pursuant to Internal Revenue Code Section 857(b)(3)(C) and Treasury Regulation §1.857-6(e). Year Ended December 31, 2017 2016 2015 Ordinary income $ 0.40 59 % $ 0.47 69 % $ 0.48 69 % Capital Gain 0.18 26 % — — % — — % Return of capital 0.10 15 % 0.21 31 % 0.21 31 % Total distributions paid $ 0.68 100 % $ 0.68 100 % $ 0.69 100 %
Schedule of activity for noncontrolling interests	The following summarizes the activity for noncontrolling interests recorded as equity for the nine months ended September 30, 2018 and year ended December 31, 2017 : Nine Months Ended September 30, 2018 Year Ended December 31, 2017 Beginning balance $ 31,105 $ 30,114 Distributions to noncontrolling interests (3,267 ) (4,369 ) Allocated distributions to noncontrolling interests subject to redemption (10 ) (13 ) Net income 671 5,120 Other comprehensive income 224 253 Ending balance $ 28,723 $ 31,105

Noncontrolling Interest (Tables

Noncontrolling Interest (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interest [Table Text Block]	The following summarizes the activity for noncontrolling interests for the nine months ended September 30, 2018 and the year ended December 31, 2017 : Nine Months Ended September 30, 2018 Year Ended December 31, 2017 Beginning balance $ 76 $ 84 Issuance of limited partnership units 1,185 — Distributions to noncontrolling interests (50 ) (11 ) Net (loss) income allocation (1 ) 3 Other comprehensive loss (2 ) — Ending balance $ 1,208 $ 76	The following summarizes the activity for noncontrolling interests for the years ended December 31, 2017 , 2016 and 2015 : Year Ended December 31, 2017 2016 2015 Beginning balance $ 84 $ 98 $ 139 Distributions to noncontrolling interests (11 ) (11 ) (11 ) Net income (loss) 3 (3 ) (30 ) Ending balance $ 76 $ 84 $ 98

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Schedule of related party transactions	Summarized below are the related party costs incurred by the Company for the nine months ended September 30, 2018 , and 2017 , respectively, and amounts payable as of September 30, 2018 and December 31, 2017 : Incurred for the Nine Months Ended September 30, Payable as of September 30, Payable as of December 31, 2018 2017 2018 2017 Expensed Corporate operating expenses $ 2,168 $ 1,677 $ 806 $ 658 Asset management fees (1) — 8,027 — — Property management fees 1,365 1,347 153 158 Performance distribution allocation 6,200 213 6,224 2,394 Advisory fees 6,970 273 784 762 Capitalized/Offering Acquisition fees and (2) — 1,099 — — Organization and offering expense 1,113 250 1,305 (6) 192 Other costs advanced by the Advisor 938 604 319 285 Selling commissions (3) 66 1,127 — — Dealer Manager fees 11 393 — — Stockholder servicing fee (4) 175 565 9,353 12,377 Advisor advances: (5) Organization and offering 45 136 44 8 Dealer Manager fees — 791 — 62 Total $ 19,051 $ 16,502 $ 18,988 $ 16,896 (1) As part of the Follow-On Offering, the Company's new management compensation structure no longer includes asset management fees. (2) Effective September 20, 2017, the Advisor is not entitled to acquisition fees, disposition fees or financing fees; provided, however, that the Advisor will receive the compensation set forth in the original advisory agreement for the Company’s investment in an approximately 1,000,000 square foot property located at 39000 Amrheim Road, Livonia, Michigan 48150 with a total transaction price of approximately $80.0 million . (3) On September 18, 2017, the Company and the Dealer Manager entered into a dealer manager agreement for the Follow-On Offering. See the "Dealer Manager Agreement" section below for details regarding selling commissions and dealer manager fees. (4) The Dealer Manager continues to receive a stockholder servicing fee with respect to Class AA shares as detailed in the Company's IPO prospectus. The stockholder servicing fee is paid quarterly and accrues daily in an amount equal to 1/365th of 1.0% of the NAV per share of the Class AA shares, up to an aggregate of 4% of the gross proceeds of Class AA shares sold. The Company will cease paying the stockholder servicing fee with respect to the Class AA shares at the earlier of (i) the date at which the aggregate underwriting compensation from all sources equals 10% of the gross proceeds from the sale of shares in Company's IPO (excluding proceeds from sales pursuant to the related DRP); (ii) the fourth anniversary of the last day of the fiscal quarter in which the Company's IPO terminated; (iii) the date that such Class AA share is redeemed or is no longer outstanding; and (iv) the occurrence of a merger, listing on a national securities exchange, or an extraordinary transaction. (5) Pursuant to the original advisory agreement, commencing November 2, 2015, the Company remained obligated to reimburse the Advisor for organizational and offering costs incurred after such date. Terms of the organizational and offering costs are included in the Company's 2016 Annual Report on Form 10-K filed on March 15, 2017. (6) Excludes amounts in excess of the 15% organization and offering costs limitation. See Note 8, Equity , for additional details.	Summarized below are the related-party costs incurred by the Company for the years ended December 31, 2017 , 2016 and 2015 , respectively, and any related amounts payable as of December 31, 2017 and 2016 : Incurred as of December 31, Payable as of December 31, 2017 2016 2015 2017 2016 Expensed Acquisition fees and expenses $ — $ 6,324 $ 11,438 $ — $ — Operating expenses 2,336 1,622 1,911 658 18 Asset management fees 8,027 6,413 2,624 — 807 Property management fees 1,799 1,052 333 158 143 Performance distributions 2,394 — — 2,394 — Advisory Fees 2,550 — — 762 — Capitalized/Offering Acquisition fees and expenses (1) 1,099 7,606 — — — Organization and offering expense 192 — 3,150 192 — Other costs advanced by the Advisor 662 304 2,598 285 12 Preferred offering costs (2) — — 375 — — Selling commissions (3) 1,128 11,397 16,303 — 54 Dealer Manager fees (4) 393 3,949 7,303 — 18 Stockholder servicing fee 660 17,449 25 12,377 16,020 Advisor Advances: (5) Organization and offering expenses 179 2,634 382 8 2,477 Dealer Manager fees 853 8,069 765 62 2,932 Total $ 22,272 $ 66,819 $ 47,207 $ 16,896 $ 22,481 (1) Effective September 20, 2017, the Advisor is not entitled to acquisition fees, disposition fees or financing fees; provided, however, that the Advisor will receive the compensation set forth in the Original Advisory Agreement for the Company’s investment in an approximately 1,000,000 square foot property located at 39000 Amrheim Road, Livonia, Michigan 48150 with a total transaction price of approximately $80 million . (2) The Company recognized a redemption premium on preferred units issued to an affiliate of approximately $0.4 million , which represented a write-off of original issuance costs. (3) On September 18, 2017, the Company and the Dealer Manager entered into a dealer manager agreement for the follow-on offering. See the “Dealer Manager Agreement” section below for details regarding selling commissions and dealer manager fees. (4) The Dealer Manager continues to receive a stockholder servicing fee with respect to Class AA shares as detailed in the Company’s IPO prospectus. The stockholder servicing fee is paid quarterly and accrues daily in an amount equal to 1/365th of 1% of the NAV per share of the Class AA shares, up to an aggregate of 4% of the gross proceeds of Class AA shares sold. The Company will cease paying the stockholder servicing fee with respect to the Class AA shares at the earlier of (i) the date at which the aggregate underwriting compensation from all sources equals 10% of the gross proceeds from the sale of shares in the Company’s IPO (excluding proceeds from sales pursuant to the related DRP); (ii) the fourth anniversary of the last day of the fiscal quarter in which the Company’s IPO terminated; (iii) the date that such Class AA share is redeemed or is no longer outstanding; and (iv) the occurrence of a merger, listing on a national securities exchange, or an extraordinary transaction. (5) Pursuant to the Original Advisory Agreement, commencing November 2, 2015, the Company remained obligated to reimburse the Advisor for organizational and offering costs incurred after such date. Terms of the organizational and offering costs are included in the Company’s 2016 Annual Report on Form 10-K filed on March 15, 2017.
Griffin Capital Essential Asset REIT, Inc. [Member]
Related Party Transaction [Line Items]
Schedule of related party transactions	Summarized below are the related party costs incurred by the Company for the nine months ended September 30, 2018 and 2017 , respectively, and any related amounts payable as of September 30, 2018 and December 31, 2017 : Incurred for the Nine Months Payable as of Ended September 30, September 30, December 31, 2018 2017 2018 2017 Expensed Operating expenses $ 2,630 $ 1,983 $ 949 $ 670 Asset management fees 17,628 17,744 1,999 1,873 Property management fees 6,992 7,466 746 725 Costs advanced by the Advisor 396 419 324 267 Capitalized Acquisition fees (1) 5,331 — — — Leasing commissions — 1,752 — — Total, net of real estate assets held for sale $ 32,977 $ 29,364 $ 4,018 $ 3,535 Asset management fees related to real estate held for sale 42 42 5 5 Property management fees related to real estate held for sale 57 53 — 5 Total $ 33,076 $ 29,459 $ 4,023 $ 3,545 (1) Acquisition fees related to the acquisitions of Quaker, McKesson, and Shaw were capitalized as the acquisition did not meet the business combination criteria.	Summarized below are the related-party costs incurred by the Company for the years ended December 31, 2017 , 2016 and 2015 , respectively, and any related amounts payable as of December 31, 2017 and 2016 : Incurred for the Year Ended December 31, Payable as of December 31, 2017 2016 2015 2017 2016 Expensed Acquisition fees and expenses $ — $ 1,322 $ 35,210 $ — $ — Operating expenses 2,652 1,525 1,608 670 — Asset management fees 23,499 23,530 19,389 1,878 1,982 Property management fees 9,782 9,740 7,622 730 737 Disposition fees (1) 1,950 — 640 — — Costs advanced by the Advisor 587 73 53 267 — Capitalized Acquisition fees (2) 3,791 — — — — Leasing commissions 1,752 — 2,105 — — Total $ 44,013 $ 36,190 $ 66,627 $ 3,545 $ 2,719 (1) Disposition fees with respect to real estate sold are included in the gain on sale of real estate in the accompanying consolidated statements of operations. (2) Acquisition fees related to the LPL acquisition were capitalized as the acquisition did not meet the business combination criteria (see Note 3, Real Estate, for additional details).

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Griffin Capital Essential Asset REIT, Inc. [Member]
Other Commitments [Line Items]
Summary of remaining required payments under the terms of the ground lease	As of September 30, 2018 , the remaining required payments under the terms of the ground leases are as follows: September 30, 2018 Remaining 2018 $ 258 2019 1,032 2020 1,032 2021 1,032 2022 1,072 Thereafter 200,446 Total $ 204,872	As of December 31, 2017 , the remaining required payments under the terms of the ground lease are as follows: December 31, 2017 2018 $ 198 2019 198 2020 198 2021 198 2022 218 Thereafter 33,631 Total $ 34,641

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information [Line Items]
Schedule of quarterly financial information	Presented below is a summary of the unaudited quarterly financial information for the years ended December 31, 2017 and 2016 : 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue $ 25,972 $ 26,546 $ 27,349 $ 27,514 Net income $ 3,124 $ 3,365 $ 3,099 $ 1,531 Net income attributable to common stockholders $ 3,123 $ 3,364 $ 3,098 $ 1,531 Net income per share (1) $ 0.04 $ 0.04 $ 0.04 $ 0.03 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue $ 12,502 $ 13,330 $ 16,334 $ 20,646 Net (loss)/income $ (1,141 ) $ (2,825 ) $ (2,736 ) $ 595 Net (loss)/income attributable to common stockholders $ (1,140 ) $ (2,824 ) $ (2,735 ) $ 595 Net (loss)/income per share (1) $ (0.03 ) $ (0.06 ) $ (0.05 ) $ 0.01 (1) Amounts were retroactively adjusted to reflect stock dividends. (See Note 2, Basis of Presentation and Summary of Significant Accounting Policies, for additional details).
Griffin Capital Essential Asset REIT, Inc. [Member]
Quarterly Financial Information [Line Items]
Schedule of quarterly financial information	Presented below is a summary of the unaudited quarterly financial information for the years ended December 31, 2017 and 2016 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue $ 96,708 $ 82,772 $ 85,132 $ 81,878 Income before other income and (expenses) $ 26,787 $ 17,685 $ 22,394 $ 15,428 Net income $ 14,306 $ 9,160 $ 9,445 $ 113,222 Net income attributable to common stockholders $ 13,726 $ 8,756 $ 9,029 $ 109,146 Net income attributable to common stockholders per share $ 0.08 $ 0.05 $ 0.05 $ 0.64 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenue (1) $ 86,732 $ 86,588 $ 86,736 $ 84,218 Income before other income and (expenses) $ 22,973 $ 18,841 $ 19,378 $ 12,339 Net income $ 12,386 $ 6,581 $ 7,131 $ 457 Net income attributable to common stockholders $ 11,891 $ 6,248 $ 6,795 $ 351 Net income attributable to common stockholders per share $ 0.07 $ 0.04 $ 0.04 $ — (1) Amounts were reclassified to conform to the current period presentation. See Note 2, Basis of Presentation and Summary of Significant Accounting Policies, for additional details.

Organization - Narrative (Detai

Organization - Narrative (Details)	May 02, 2018	Sep. 20, 2017USD ($)stock_classshares	Apr. 06, 2017shares	Jun. 30, 2015shares	Sep. 30, 2018USD ($)propertyshares	Sep. 30, 2018USD ($)propertyshares	Sep. 30, 2017shares	Sep. 30, 2018USD ($)propertyshares	Sep. 30, 2017shares	Dec. 31, 2017USD ($)property$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2017USD ($)property$ / sharesshares	Sep. 30, 2018USD ($)propertyshares	Dec. 31, 2014USD ($)offeringshares	Jul. 05, 2018	Jun. 09, 2017USD ($)	Sep. 22, 2015USD ($)	Jul. 31, 2014USD ($)	May 07, 2014USD ($)	Feb. 11, 2014USD ($)	Aug. 29, 2008USD ($)
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $																		$ 2,200,000,000
Number of shares outstanding (in shares)					77,660,266	77,660,266		77,660,266		77,175,283	70,939,647	77,175,283	77,660,266
Value of shares redeemed | $								$ 5,292,000
Stock redeemed during period (in shares)								2,791,262		790,941
Limited liability partnership percentage of interest held (percent)																				99.00%
Limited partnership, purchase price | $																				$ 200,000
Initial capital contribution | $																				$ 1,000
General partner percentage interest obtained (percent)																				1.00%
Shares Authorized, Common and Preferred Stock										1,000,000,000		1,000,000,000
Common Stock, Shares Authorized										800,000,000	700,000,000	800,000,000
Common Stock, Par or Stated Value Per Share | $ / shares										$ 0.001	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized										200,000,000		200,000,000
Affiliated Entity
Subsidiary, Sale of Stock [Line Items]
Aggregate number of shares to be purchased under transaction agreement (shares)		263,992
Related Party Transaction, Other Revenues from Transactions with Related Party | $		$ 2,500,000
New Share Redemption Program [Member]
Subsidiary, Sale of Stock [Line Items]
Value of shares redeemed | $													$ 6,700,000
Stock redeemed during period (in shares)					693,487	693,487	0	693,487	0
Minimum holding period for stock to be redeemed from stockholder by the Company								1 year		1 year
Percentage of Net Asset Value of shares (percent)					100.00%	100.00%		100.00%					100.00%		100.00%
IPO Share Redemption Program [Member]
Subsidiary, Sale of Stock [Line Items]
Minimum holding period for stock to be redeemed from stockholder by the Company	1 year
Percentage of Net Asset Value of shares (percent)	100.00%
Share Redemption Program
Subsidiary, Sale of Stock [Line Items]
Value of shares redeemed | $								$ 12,200,000		$ 5,700,000	$ 1,600,000	$ 7,400,000
Stock redeemed during period (in shares)					585,525		146,083	1,306,834	413,842	623,499	167,442	790,941
Minimum holding period for stock to be redeemed from stockholder by the Company										1 year
Percentage of Net Asset Value of shares (percent)										100.00%		100.00%
Common Class T [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					226,297	226,297		226,297		4,148	0	4,148	226,297
Stock redeemed during period (in shares)								0		0
Common Stock, Shares Authorized										150,000,000		150,000,000
Common Class S [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					277	277		277		268	0	268	277
Stock redeemed during period (in shares)								0		0
Common Stock, Shares Authorized										150,000,000		150,000,000
Common Class D [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					19,157	19,157		19,157		268	0	268	19,157
Stock redeemed during period (in shares)								0		0
Common Stock, Shares Authorized										150,000,000		150,000,000
Common Class I [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					803,069	803,069		803,069		267,476	0	267,476	803,069
Stock redeemed during period (in shares)								0		0
Common Stock, Shares Authorized										150,000,000		150,000,000
Common Class A [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					25,781,325	25,781,325		25,781,325		25,995,943	25,562,982	25,995,943	25,781,325
Stock redeemed during period (in shares)								1,351,178		557,206
Common Stock, Shares Authorized										70,000,000		70,000,000
Common Class AA [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					49,840,818	49,840,818		49,840,818		49,942,471	44,595,631	49,942,471	49,840,818
Stock redeemed during period (in shares)								1,434,491		233,735
Common Stock, Shares Authorized										120,000,000		120,000,000
Common Class AAA [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares outstanding (in shares)					989,323	989,323		989,323		964,709	781,034	964,709	989,323
Stock redeemed during period (in shares)								5,593		0
Common Stock, Shares Authorized										10,000,000		10,000,000
Sale to Public
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $																		2,000,000,000
Common stock issued (shares)					73,694,264	73,694,264		73,694,264		72,931,727		72,931,727	73,694,264
Sale to Public | New Share Redemption Program [Member]
Subsidiary, Sale of Stock [Line Items]
Minimum holding period for stock to be redeemed from stockholder by the Company								4 years		4 years
Sale to Public | Share Redemption Program
Subsidiary, Sale of Stock [Line Items]
Minimum holding period for stock to be redeemed from stockholder by the Company								4 years		4 years
Sale to Public | Common Class T [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					224,647	224,647		224,647		4,144		4,144	224,647
Sale to Public | Common Class S [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					264	264		264		264		264	264
Sale to Public | Common Class D [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					18,921	18,921		18,921		264		264	18,921
Sale to Public | Common Class I [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					786,573	786,573		786,573		263,200		263,200	786,573
Sale to Public | Common Class A [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					24,199,764	24,199,764		24,199,764		24,199,760		24,199,760	24,199,764
Sale to Public | Common Class AA [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					47,562,870	47,562,870		47,562,870		47,562,870		47,562,870	47,562,870
Sale to Public | Common Class AAA [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					901,225	901,225		901,225		901,225		901,225	901,225
Distribution Reinvestment Plan
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $		200,000,000
Equity offering, termination notice period			10 days
Common stock issued (shares)					6,152,779	6,152,779		6,152,779		4,440,514		4,440,514	6,152,779
Common Stock Approved under Common Stock Distribution Reinvestment Plan | $		200,000,000																$ 200,000,000
Common Stock Offering, Registration Statement, Shares			3,000,000
Distribution Reinvestment Plan | Common Class T [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					1,650	1,650		1,650		4		4	1,650
Distribution Reinvestment Plan | Common Class S [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					13	13		13		4		4	13
Distribution Reinvestment Plan | Common Class D [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					236	236		236		4		4	236
Distribution Reinvestment Plan | Common Class I [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					16,496	16,496		16,496		4,276		4,276	16,496
Distribution Reinvestment Plan | Common Class A [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					2,669,097	2,669,097		2,669,097		2,089,748		2,089,748	2,669,097
Distribution Reinvestment Plan | Common Class AA [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					3,412,273	3,412,273		3,412,273		2,313,170		2,313,170	3,412,273
Distribution Reinvestment Plan | Common Class AAA [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock issued (shares)					53,014	53,014		53,014		33,308		33,308	53,014
Follow-on Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $		$ 2,200,000,000
Number of New Classes of Common Stock | stock_class		4
Primary Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $		$ 2,000,000,000
Griffin Capital Essential Asset REIT, Inc. [Member]
Subsidiary, Sale of Stock [Line Items]
Agreement term								1 year		1 year
Renewal period term								1 year		1 year
Number of public offerings | offering														2
Number of shares outstanding (in shares)					166,253,534	166,253,534		166,253,534		170,906,111	176,032,871	170,906,111	166,253,534
Redemptions payable | $					$ 6,653,000	$ 6,653,000		$ 6,653,000		$ 20,382,000	$ 11,565,000	$ 20,382,000	$ 6,653,000
Limited partnership, purchase price | $																					$ 200,000
Initial capital contribution | $																					$ 1,000
General partner percentage interest obtained (percent)																					1.00%
Limited partnership, Company's ownership interest (percent)								96.00%		96.00%
Number of properties contributed | property					5	5		5		5		5	5
Limited Partnership number of units redeemed (shares)								0		0	0
Common Stock, Shares Authorized										700,000,000	700,000,000	700,000,000
Common Stock, Par or Stated Value Per Share | $ / shares										$ 0.001	$ 0.001	$ 0.001
Griffin Capital Essential Asset REIT, Inc. [Member] | Advisor
Subsidiary, Sale of Stock [Line Items]
Limited liability partnership percentage of interest held (percent)																					99.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Sponsor and Affiliates
Subsidiary, Sale of Stock [Line Items]
Limited liability partnership percentage of interest held (percent)					2.00%	2.00%		2.00%		2.00%		2.00%	2.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Third parties
Subsidiary, Sale of Stock [Line Items]
Limited liability partnership percentage of interest held (percent)					2.00%	2.00%		2.00%		2.00%		2.00%	2.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Chief Executive Officer
Subsidiary, Sale of Stock [Line Items]
Partnership units owned (shares)					2,100,000	2,100,000		2,100,000		2,100,000		2,100,000	2,100,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Share Redemption Program
Subsidiary, Sale of Stock [Line Items]
Value of shares redeemed | $								$ 76,900,000		$ 98,900,000	$ 41,400,000
Redemptions payable | $					$ 6,700,000	$ 6,700,000		$ 6,700,000		$ 20,400,000		$ 20,400,000	$ 6,700,000
Stock redeemed during period (in shares)					1,311,582		2,936,150	8,013,521	6,155,290	9,931,245	4,164,955
Percentage of Net Asset Value of shares (percent)					95.00%	95.00%		95.00%		95.00%		95.00%	95.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Sale to Public
Subsidiary, Sale of Stock [Line Items]
Number of shares issued (in shares)				41,800,000										126,592,885
Griffin Capital Essential Asset REIT, Inc. [Member] | Private Offering
Subsidiary, Sale of Stock [Line Items]
Proceeds from issuance of private placement | $								$ 1,500,000,000		$ 1,500,000,000				$ 1,300,000,000
Common stock issued (shares)					190,116,953	190,116,953		190,116,953		186,756,009		186,756,009	190,116,953
Griffin Capital Essential Asset REIT, Inc. [Member] | 2014 Distribution Reinvestment Plan Offering
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $																			$ 75,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Distribution Reinvestment Plan
Subsidiary, Sale of Stock [Line Items]
Value of shares to be registered | $																$ 10,000,000	$ 100,000,000
Equity offering, termination notice period								10 days		10 days
Common stock issued | $					$ 245,600,000	$ 245,600,000		$ 245,600,000		$ 211,900,000	$ 162,400,000	$ 211,900,000	$ 245,600,000

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)segmentSegment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Accounting Policies [Line Items]
Asset Impairment Charges					$ 0
Restricted Cash and Cash Equivalents	$ 14,642,000		$ 14,642,000		12,886,000	$ 14,221,000
Cash Equivalents, at Carrying Value					0	0
Cash, FDIC Insured Amount					$ 250,000
Number of reportable segments | segment			1		1
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Restricted Cash and Cash Equivalents	22,365,000		$ 22,365,000		$ 174,132,000	13,420,000
Impairment provision	$ 0	$ 0	$ 0	$ 5,675,000	8,460,000	0	$ 0
Cash Equivalents, at Carrying Value					0	0
Cash, FDIC Insured Amount					$ 250,000
Number of reportable segments			1		1
Building [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					40 years
Minimum | Building [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					25 years
Minimum | Building Improvements [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					5 years
Minimum | Building Improvements [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					5 years
Minimum | Land Improvements [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					15 years
Minimum | Land Improvements [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					15 years
Maximum | Building [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					40 years
Maximum | Building Improvements [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					20 years
Maximum | Building Improvements [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					20 years
Maximum | Land Improvements [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					25 years
Maximum | Land Improvements [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life					25 years
Section 1031 Exchanges [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Accounting Policies [Line Items]
Restricted Cash					$ 154,900,000	$ 0

Real Estate - Narrative (Detail

Real Estate - Narrative (Details) $ in Thousands, ft² in Millions	Nov. 20, 2017USD ($)	Oct. 19, 2017USD ($)	Jun. 30, 2017USD ($)	Sep. 30, 2018USD ($)ft²statePropertybuildingpropertyparcel	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)ft²statePropertybuildingproperty	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Real Estate [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						10 years 3 months 18 days	11 years 4 months 24 days
Number of properties | Property				27		27
Number of Buildings | building				35		35
Number of states | state				17		17
Depreciation				$ 15,284	$ 15,053	$ 20,194	$ 11,630	$ 4,916
Amortization expense				18,099	17,657	23,756	$ 16,264	7,145
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net				$ 1,100,000		$ 1,100,000
Approx. Square Feet | ft²				7.3		7.3
Amortization				$ 18,100		$ 23,800
Minimum
Real Estate [Line Items]
Real Estate Acquisition, As-if-Vacant Valuation, Discount Rate						5.75%
Maximum
Real Estate [Line Items]
Real Estate Acquisition, As-if-Vacant Valuation, Discount Rate						8.25%
Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Number Of Properties Serving As Collateral | property						8
Gain (Loss) on Termination of Lease						$ 12,800
Finance Lease, Weighted Average Remaining Lease Term						6 years 6 months 4 days	7 years 1 month 6 days
Number of properties | property				76		73
Number of states | state				20		20
Number of land parcels held for future development | parcel				2
Purchase price				$ 3,000,000		$ 2,800,000
Depreciation				44,390	42,244	55,982	$ 56,707	43,320
Amortization expense				44,868	46,539	$ 60,601	$ 74,142	$ 69,428
Lease Termination Fee Payment Period						2 years
Quarterly Lease Termination Fee Payment						$ 1,600
Unamortized In-Place Lease Intangible Assets Accelerated As A Result Of Lease Termination						3,400
Deferred Rent Revenue Recognized During Period				$ 10,210	$ 8,508	400
Impairment Provision Related To Lease Intangibles						5,700
Real Estate Not Recoverable						$ 2,800
Griffin Capital Essential Asset REIT, Inc. [Member] | Discount rate
Real Estate [Line Items]
Discount rate (percent)						0.07
Griffin Capital Essential Asset REIT, Inc. [Member] | Discount rate | Minimum
Real Estate [Line Items]
Discount rate (percent)				0.0625
Griffin Capital Essential Asset REIT, Inc. [Member] | Discount rate | Maximum
Real Estate [Line Items]
Discount rate (percent)				0.0775
12669 Encinitas Avenue [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Proceeds from sale of property			$ 10,000
Real Estate Investments, Net			5,400
Gains (Losses) on Sales of Investment Real Estate			$ 4,000
One Century Plaza, Nashville, TN [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Proceeds from sale of property		$ 100,000
Real Estate Investments, Net		67,900
Gains (Losses) on Sales of Investment Real Estate		$ 32,100
DreamWorks Property [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Proceeds from sale of property	$ 290,000
Real Estate Investments, Net	210,100
Gains (Losses) on Sales of Investment Real Estate	$ 79,900

Real Estate - Aggregate Purchas

Real Estate - Aggregate Purchase Price (Details)	Jul. 31, 2017USD ($)	Nov. 02, 2015	Sep. 30, 2018USD ($)ft²	Dec. 31, 2017USD ($)ft²	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Real Estate [Line Items]
Related Party Acquisition Fee for Purchase of Property, Base Rate				2.00%
Acquisitions				$ 45,016,000	$ 615,972,000	$ 516,965,000
Approx. Square Feet | ft²			7,300,000	7,300,000
Related Party Acquisition, Percentage of Acquisition Value				1.00%
Related Party Acquisition Fee for Purchase of Property		3.85%
Related Party Acquisition Fee for Purchase of Property, Contingent Rate		1.85%
Acquisition Fee, Amount Retained Subject to Conditions				$ 5,000,000
Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Acquisitions				$ 133,747,000	$ 42,438,000	$ 1,087,153,000
Acquisition Fees and Expenses			$ 5,700,000
Percentage of acquisition fees (percent)			2.50%	2.50%
Percent reimbursed (percent)			0.50%	0.50%
Griffin Capital Essential Asset REIT, Inc. [Member] | HealthSpring [Member]
Real Estate [Line Items]
Purchase Price				$ 130,000,000
Approx. Square Feet | ft²				451,600
Acquisition Fees and Expenses				$ 3,791,000
Percentage of acquisition fees (percent)				2.50%
Percent reimbursed (percent)				0.50%
Griffin Capital Essential Asset REIT, Inc. [Member] | Quaker Property [Member]
Real Estate [Line Items]
Purchase Price			$ 59,600,000
Approx. Square Feet | ft²			605,400
Acquisition Fees and Expenses			$ 1,777,000
Percentage of acquisition fees (percent)			2.50%
Percent reimbursed (percent)			0.50%
Griffin Capital Essential Asset REIT, Inc. [Member] | McKesson Property [Member]
Real Estate [Line Items]
Purchase Price			$ 67,000,000
Approx. Square Feet | ft²			271,100
Acquisition Fees and Expenses			$ 2,139,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Shaw Property [Member]
Real Estate [Line Items]
Purchase Price			$ 56,526,000
Approx. Square Feet | ft²			1,001,500
Acquisition Fees and Expenses			$ 1,782,000
The Allstate Property [Member]
Real Estate [Line Items]
Acquisitions				$ 14,750,000
Approx. Square Feet | ft²				70,300
Acquisition Fees and Expenses				$ 1,200,000
Acquisition Related Costs to Affiliates				402,000
Line of Credit Draw				273,000
Business Combination, Consideration Transferred				14,800,000
MISO Property [Member]
Real Estate [Line Items]
Acquisitions				$ 28,600,000
Approx. Square Feet | ft²				133,400
Acquisition Related Costs to Affiliates				$ 696,000
Line of Credit Draw				$ 529,000
Contingent Advisor Payment Holdback - Organization and Offering Expenses and Dealer Manager Fees [Member]
Real Estate [Line Items]
Payments of Contingent Advisor Payment Holdback	$ 5,000,000

Real Estate - Summary of Purcha

Real Estate - Summary of Purchase Price Allocation (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)ft²	Dec. 31, 2017USD ($)ft²	Dec. 31, 2016USD ($)
Real Estate [Line Items]
Land	$ 122,482	$ 122,482	$ 117,569
In-place lease valuation - above (below) market	(62,070)	(62,070)	(61,069)
Payable- Ground Lease Payments	$ (853,708)	$ (906,059)
Approx. Square Feet | ft²	7,300,000	7,300,000
Investment Building and Building Improvements	$ 819,079	$ 815,721	787,999
Deferred Costs, Leasing, Gross	240,364	240,364	227,407
In-place lease valuation (above market)	4,046	4,046	3,828
Quaker Property [Member]
Real Estate [Line Items]
Receivable- Ground Lease	0
Payable- Ground Lease Payments	0
McKesson Property [Member]
Real Estate [Line Items]
Receivable- Ground Lease	0
Payable- Ground Lease Payments	0
Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Land	352,419	341,432	374,557
Payable- Ground Lease Payments	(1,670,100)	(1,633,495)
Acquisition cost	5,700
Investment Building and Building Improvements	2,172,884	2,022,372	2,102,785
Deferred Costs, Leasing, Gross	532,207	494,871	541,646
In-place lease valuation (above market)	42,736	42,736	47,419
In-place lease valuation (below market)	(55,482)	(49,774)	$ (51,966)
Griffin Capital Essential Asset REIT, Inc. [Member] | Griffin Capital (Highway 94) Investors, DST [Member]
Real Estate [Line Items]
Land		5,886
Building and improvements		108,000
Tenant origination and absorption costs		19,859
Real Estate Investments, Net		134,128
Acquisition cost		4,100
Griffin Capital Essential Asset REIT, Inc. [Member] | HealthSpring [Member]
Real Estate [Line Items]
Purchase Price		130,000
Acquisition cost		$ 3,791
Approx. Square Feet | ft²		451,600
Griffin Capital Essential Asset REIT, Inc. [Member] | Quaker Property [Member]
Real Estate [Line Items]
Purchase Price	59,600
Land	5,433
Building and improvements	50,953
Tenant origination and absorption costs	4,387
In-place lease valuation - above (below) market	(502)
Real Estate Investments, Net	60,271
Acquisition cost	$ 1,777
Approx. Square Feet | ft²	605,400
Griffin Capital Essential Asset REIT, Inc. [Member] | McKesson Property [Member]
Real Estate [Line Items]
Purchase Price	$ 67,000
Land	312
Building and improvements	45,109
Tenant origination and absorption costs	24,652
In-place lease valuation - above (below) market	(933)
Real Estate Investments, Net	69,140
Acquisition cost	$ 2,139
Approx. Square Feet | ft²	271,100
Griffin Capital Essential Asset REIT, Inc. [Member] | Shaw Property [Member]
Real Estate [Line Items]
Purchase Price	$ 56,526
Land	5,465
Building and improvements	48,820
Tenant origination and absorption costs	8,297
In-place lease valuation - above (below) market	(4,273)
Receivable- Ground Lease	2,008
Payable- Ground Lease Payments	(2,008)
Real Estate Investments, Net	58,309
Acquisition cost	$ 1,782
Approx. Square Feet | ft²	1,001,500
Griffin Capital Essential Asset REIT, Inc. [Member] | Leases, Acquired-in-Place, Market Adjustment [Member] | Griffin Capital (Highway 94) Investors, DST [Member]
Real Estate [Line Items]
In-place lease valuation - above (below) market		$ 383
The Allstate Property [Member]
Real Estate [Line Items]
Land		1,808
Real Estate Investments, Net		14,897
Acquisition cost		$ 1,200
Approx. Square Feet | ft²		70,300
Investment Building and Building Improvements		$ 9,071
Deferred Costs, Leasing, Gross		5,019
In-place lease valuation (above market)		0
In-place lease valuation (below market)		(1,001)
MISO Property [Member]
Real Estate [Line Items]
Land		3,104
Real Estate Investments, Net		$ 29,336
Approx. Square Feet | ft²		133,400
Investment Building and Building Improvements		$ 18,077
Deferred Costs, Leasing, Gross		7,937
In-place lease valuation (above market)		218
In-place lease valuation (below market)		$ 0

Real Estate - Future Minimum Co

Real Estate - Future Minimum Contractual Rent Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of future minimum net rent payments
Remaining 2,018	$ 19,311
2,018		$ 71,662
2,019	78,887	78,887
2,020	80,492	80,492
2,021	72,677	72,677
2,022	73,538	73,538
Thereafter	528,803	528,803
Total	853,708	906,059
Griffin Capital Essential Asset REIT, Inc. [Member]
Schedule of future minimum net rent payments
Remaining 2,018	61,164
2,018		231,620
2,019	226,557	210,449
2,020	204,640	188,653
2,021	191,182	174,053
2,022	182,708	164,494
Thereafter	803,849	664,226
Total	$ 1,670,100	$ 1,633,495

Real Estate - Intangibles (Deta

Real Estate - Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Real Estate [Line Items]
Below Market Lease, Gross	$ (62,070)	$ (62,070)	$ (61,069)
Below Market Lease, Accumulated Amortization	14,564	10,775	5,750
Below Market Lease, Net	(47,506)	(51,295)	(55,319)
Finite-Lived Intangible Assets, Net	175,100	193,199
Schedule of in-place lease valuation
In-place lease valuation (above market)	4,046	4,046	3,828
In-place lease valuation (above market) - accumulated amortization	(1,030)	(752)	(300)
In-place lease valuation (above market), net	3,016	3,294	3,528
Griffin Capital Essential Asset REIT, Inc. [Member]
Schedule of in-place lease valuation
In-place lease valuation (above market)	42,736	42,736	47,419
In-place lease valuation (above market) - accumulated amortization	(31,065)	(26,613)	(20,543)
In-place lease valuation (above market), net	11,671	16,123	26,876
Ground leasehold interest (below market)	2,254	2,255	2,254
Ground leasehold interest (below market) - accumulated amortization	(129)	(109)	(82)
Ground leasehold interest (below market), net	2,125	2,146	2,172
Intangible assets, net	13,796	18,269	29,048
In-place lease valuation (below market)	(55,482)	(49,774)	(51,966)
In-place lease valuation (below market) - accumulated amortization	30,779	26,193	20,330
In-place lease valuation (below market), net	(24,703)	(23,581)	(31,636)
Tenant origination and absorption cost	532,207	494,871	541,646
Tenant origination and absorption cost - accumulated amortization	(284,763)	(242,108)	(197,173)
Tenant origination and absorption cost, net	247,444	252,763	344,473
Tenant origination and absorption costs
Real Estate [Line Items]
In-place lease valuation - above (below) market	240,364	240,364	227,407
Finite-Lived Intangible Assets, Accumulated Amortization	$ (65,264)	(47,165)	(23,409)
Finite-Lived Intangible Assets, Net		$ 193,199	$ 203,998

Real Estate - Restricted Cash (

Real Estate - Restricted Cash (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2018	Dec. 31, 2016
Real Estate [Line Items]
Restricted Cash and Cash Equivalents	$ 12,886	$ 14,642	$ 14,221
Griffin Capital Essential Asset REIT, Inc. [Member]
Real Estate [Line Items]
Restricted Cash and Cash Equivalents	174,132	22,365	$ 13,420
Griffin Capital Essential Asset REIT, Inc. [Member] | Real Estate Asset Acquisitions and Contributions [Member] | Cash reserves
Real Estate [Line Items]
Restricted Cash and Cash Equivalents	17,034	20,619
Griffin Capital Essential Asset REIT, Inc. [Member] | Real Estate Asset Acquisitions and Contributions [Member] | Midland mortgage loan restricted lockbox
Real Estate [Line Items]
Restricted Cash and Cash Equivalents	2,158	1,746
Griffin Capital Essential Asset REIT, Inc. [Member] | Real Estate Asset Acquisitions and Contributions [Member] | 1031 Exchange Funds
Real Estate [Line Items]
Restricted Cash and Cash Equivalents	154,940	$ 0
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Restricted Cash [Roll Forward]
Beginning balance	13,420
Additions	376,481
Deductions	(215,770)
Ending balance	174,131
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Tenant Improvement Reserves [Member]
Restricted Cash [Roll Forward]
Beginning balance	9,238
Additions	5,468
Deductions	(1,071)
Ending balance	13,635
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Midland mortgage loan restricted lockbox
Restricted Cash [Roll Forward]
Beginning balance	1,468
Additions	2,158
Deductions	(1,468)
Ending balance	2,158
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | 1031 Exchange Funds
Restricted Cash [Roll Forward]
Beginning balance	0
Additions	286,711
Deductions	(131,771)
Ending balance	154,940
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Midland Mortgage Loan Reserves [Member]
Restricted Cash [Roll Forward]
Beginning balance	67
Additions	323
Deductions	0
Ending balance	390
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Real Estate Tax Reserves [Member]
Restricted Cash [Roll Forward]
Beginning balance	1,645
Additions	3,344
Deductions	(2,892)
Ending balance	2,097
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Property Insurance Reserves [Member]
Restricted Cash [Roll Forward]
Beginning balance	257
Additions	467
Deductions	(499)
Ending balance	225
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Rent Abatement Reserve [Member]
Restricted Cash [Roll Forward]
Beginning balance	0
Additions	731
Deductions	(390)
Ending balance	341
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Restricted Deposit/Leasing Commission Reserve [Member]
Restricted Cash [Roll Forward]
Beginning balance	745
Additions	4
Deductions	(404)
Ending balance	345
Leases, Acquired-in-Place [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Holdback Escrow [Member]
Restricted Cash [Roll Forward]
Beginning balance	0
Additions	77,275
Deductions	(77,275)
Ending balance	$ 0

Real Estate - Major Components

Real Estate - Major Components of Assets and Liabilities Related to Real Estate Held for Sale (Details) - Griffin Capital Essential Asset REIT, Inc. [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets	$ 2,711	$ 2,959
Total liabilities	293	537
Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total real estate	3,575	3,575
Less: accumulated depreciation and amortization	(868)	(794)
Total real estate, net	2,707	2,781
Other assets	4	178
Total assets	2,711	2,959
Accrued expenses and other liabilities	288	527
Accrued expenses and other liabilities	5	10
Total liabilities	293	537
Land | Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total real estate	589	589
Building and improvements | Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total real estate	2,493	2,493
Tenant origination and absorption costs | Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total real estate	$ 493	$ 493

Real Estate Real Estate - Amort

Real Estate Real Estate - Amortization Income (Expense) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amortization of above and below Market Leases	$ (3,511)	$ (3,389)	$ (4,573)	$ (3,592)	$ (1,858)
Amortization of Deferred Leasing Fees			23,756	16,264	7,145
Griffin Capital Essential Asset REIT, Inc. [Member]
Remaining 2,018	(386)
Remaining 2,018	11,150
Remaining 2,018	21
Remaining 2,018	2,389
2,019	(2,464)
2,019	38,096
2,019	21
2,019	4,765
2,020	(936)
2,020	29,867
2,020	21
2,020	4,712
2,021	(717)
2,021	25,170
2,021	21
2,021	4,830
2,022	(1,058)
2,022	22,938
2,022	21
2,022	4,818
Amortization of above and below Market Leases	$ (135)	$ 1,310	1,689	3,287	(3,785)
Amortization of Deferred Leasing Fees			59,046	72,912	69,099
Amortization Of Ground Leasehold Interest			27	28	28
Amortization of Other Leasing Costs			$ 1,527	$ 1,202	$ 301

Real Estate Real Estate - Matur

Real Estate Real Estate - Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [Abstract]
Below Market Lease, Amortization Income, Next Twelve Months		$ (4,695)
Below Market Lease, Amortization Income, Remainder of Fiscal Year	$ (1,170)
Below Market Lease, Amortization Income, Year Two	(4,695)	(4,695)
Below Market Lease, Amortization Income, Year Three	(4,695)	(4,695)
Below Market Lease, Amortization Income, Year Four	(3,799)	(3,799)
Below Market Lease, Amortization Income, Year Five	(3,799)	(3,799)
Tenant origination and absorption costs
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		24,198
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	6,033
Finite-Lived Intangible Assets, Amortization Expense, Year Two	24,198	24,198
Finite-Lived Intangible Assets, Amortization Expense, Year Three	24,198	24,198
Finite-Lived Intangible Assets, Amortization Expense, Year Four	19,715	19,715
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 19,597	19,597
Griffin Capital Essential Asset REIT, Inc. [Member]
Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [Abstract]
Below Market Lease, Amortization Income, Next Twelve Months		(1,018)
Below Market Lease, Amortization Income, Year Two		(1,856)
Below Market Lease, Amortization Income, Year Three		(770)
Below Market Lease, Amortization Income, Year Four		(630)
Below Market Lease, Amortization Income, Year Five		(1,007)
Griffin Capital Essential Asset REIT, Inc. [Member] | Tenant origination and absorption costs
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		51,363
Finite-Lived Intangible Assets, Amortization Expense, Year Two		42,721
Finite-Lived Intangible Assets, Amortization Expense, Year Three		33,302
Finite-Lived Intangible Assets, Amortization Expense, Year Four		28,724
Finite-Lived Intangible Assets, Amortization Expense, Year Five		24,918
Griffin Capital Essential Asset REIT, Inc. [Member] | Ground leasehold improvements
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		27
Finite-Lived Intangible Assets, Amortization Expense, Year Two		27
Finite-Lived Intangible Assets, Amortization Expense, Year Three		27
Finite-Lived Intangible Assets, Amortization Expense, Year Four		27
Finite-Lived Intangible Assets, Amortization Expense, Year Five		27
Griffin Capital Essential Asset REIT, Inc. [Member] | Other leasing costs
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		1,768
Finite-Lived Intangible Assets, Amortization Expense, Year Two		1,782
Finite-Lived Intangible Assets, Amortization Expense, Year Three		1,757
Finite-Lived Intangible Assets, Amortization Expense, Year Four		1,704
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 1,674

Investments - Narrative (Detail

Investments - Narrative (Details) - Griffin Capital Essential Asset REIT, Inc. [Member]	Sep. 09, 2014USD ($)ft²	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)ft²	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)ft²	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Equity contribution					$ 3,266,000	$ 0	$ 0	$ 18,129,000	$ 0
Equity in other comprehensive (loss) income of unconsolidated joint venture			$ (12,000)	$ 311,000	224,000	$ 489,000	465,000	$ 241,000	$ (189,000)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest							500,000
Heritage Common X
Schedule of Equity Method Investments [Line Items]
Total project budget			48,100,000		48,100,000
Equity method investment, liabilities			41,400,000		41,400,000
Equity contributed by the members of joint venture			$ 6,700,000		$ 6,700,000
Equity method investment, ownership (percent)			45.00%		45.00%
Equity contribution		$ 3,100,000			$ 3,266,000
Area of real estate property (in sqft) | ft²			200,000		200,000
Equity in other comprehensive (loss) income of unconsolidated joint venture					$ 0
Digital Realty Joint Venture
Schedule of Equity Method Investments [Line Items]
Equity method investment, liabilities	$ 102,000,000
Equity method investment, ownership (percent)	80.00%
Equity contribution					$ 0
Payments to acquire interest in equity method investment	$ 68,400,000
Equity method investment, property	$ 187,500,000
Area of real estate property (in sqft) | ft²	132,300
Operating leases, term of contract	5 years				4 years
Equity in other comprehensive (loss) income of unconsolidated joint venture					$ 224,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest							$ 465,000

Investments - Balance of Invest

Investments - Balance of Investments (Details) - Griffin Capital Essential Asset REIT, Inc. [Member] - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest						$ 500,000
Investments [Roll Forward]
Balance as of December 31, 2017				$ 37,114,000	$ 46,313,000	46,313,000
Initial contribution				3,266,000	0	0	$ 18,129,000	$ 0
Net loss		$ (579,000)	$ (517,000)	(1,617,000)	(1,511,000)	(2,065,000)	(1,640,000)	(1,475,000)
Distributions				(5,627,000)
Other comprehensive income		(12,000)	$ 311,000	224,000	489,000	465,000	241,000	$ (189,000)
Balance as of September 30, 2018		33,360,000		33,360,000		37,114,000	46,313,000
Digital Realty Joint Venture
Schedule of Equity Method Investments [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest						465,000
Investments [Roll Forward]
Balance as of December 31, 2017				37,114,000	$ 46,313,000	46,313,000
Initial contribution				0
Net loss				(1,617,000)		(2,065,000)
Distributions				(5,627,000)		(7,599,000)
Other comprehensive income				224,000
Balance as of September 30, 2018		30,094,000		30,094,000		37,114,000	$ 46,313,000
Heritage Common X
Investments [Roll Forward]
Balance as of December 31, 2017				0
Initial contribution	$ 3,100,000			3,266,000
Net loss				0
Distributions				0
Other comprehensive income				0
Balance as of September 30, 2018		$ 3,266,000		$ 3,266,000		$ 0

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($)	Jun. 28, 2018	Mar. 31, 2018	Sep. 29, 2017	Oct. 22, 2015	Jul. 20, 2015	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 01, 2016	Feb. 25, 2016
Debt Instrument [Line Items]
Weighted average interest rate						3.81%	3.13%
Total principal						$ 490,055,000	$ 484,728,000	$ 460,428,000
Debt Issuance Costs, Net						(8,482,000)	(2,880,000)	(3,956,000)
Debt, net						$ 481,573,000	$ 481,848,000	456,472,000
LIBOR
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate						2.11%
Debt Instrument, Basis Rate							1.57%
Revolving Credit Facility | Key Bank Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Term	4 years
Line Of Credit Facility, Extension Term	1 year
Line of Credit | Key Bank Credit Facility [Member]
Debt Instrument [Line Items]
Weighted average interest rate							2.92%
Total principal						$ 85,000	$ 357,758,000	$ 333,458,000
Contractual stated interest rate (percent)							2.87%
Effective interest rate (percent)						3.65%	3.32%
Debt Instrument, Term						4 years	4 years	4 years
Line Of Credit Facility, Extension Term						1 year	1 year	1 year
Line of Credit | Key Bank Credit Facility [Member] | LIBOR
Debt Instrument [Line Items]
Debt Instrument, Term to Determine Weighted Average Interest Rate							365 days
Debt Instrument, Term to Determine Contractual Interest Rate							360 days
Spread over variable rate (percent)		1.50%				1.30%	1.50%
Mortgages
Debt Instrument [Line Items]
Total principal						$ 376,970,000	$ 126,970,000
Mortgages | BofA / Key Bank Loan [Member]
Debt Instrument [Line Items]
Total principal						$ 250,000,000	0
Contractual stated interest rate (percent)						4.32%
Effective interest rate (percent)						4.36%
Mortgages | AIG Loan
Debt Instrument [Line Items]
Total principal						$ 126,970,000	126,970,000
Contractual stated interest rate (percent)						4.15%
Effective interest rate (percent)						4.22%
Notes Payable, Other Payables [Member] | AIG Loan
Debt Instrument [Line Items]
Total principal							$ 126,970,000	$ 126,970,000
Debt, net				$ 127,000,000
Contractual stated interest rate (percent)				4.15%			4.15%
Effective interest rate (percent)							4.22%
Debt Instrument, Term				10 years			10 years
Debt Instrument, Payment Terms, Duration Requiring Monthly Payments of Interest Only				5 years			5 years
Notes Payable, Other Payables [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Total principal						$ 113,000,000	$ 0
Effective interest rate (percent)						3.58%
Notes Payable, Other Payables [Member] | Term Loan [Member] | LIBOR
Debt Instrument [Line Items]
Spread over variable rate (percent)						1.25%
Griffin Capital Essential Asset REIT, Inc. [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount						$ 1,150,000,000
Total principal						1,363,776,000	1,397,779,000	1,458,343,000
Unamortized Deferred Financing Costs and Discounts, net						(9,426,000)	(11,695,000)	(10,808,000)
Debt Issuance Costs, Net							(11,414,000)
Debt, net						$ 1,354,350,000	$ 1,386,084,000	1,447,535,000
Griffin Capital Essential Asset REIT, Inc. [Member] | LIBOR
Debt Instrument [Line Items]
Effective interest rate (percent)						2.11%	1.56%
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility | Term Loan
Debt Instrument [Line Items]
Total principal						$ 715,000,000	$ 715,000,000	715,000,000
Effective interest rate (percent)						3.89%	3.19%
Debt Instrument, Term					4 years
Debt instrument extended term					1 year
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility | Term Loan | LIBOR
Debt Instrument [Line Items]
Spread over variable rate (percent)							1.40%
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility | Revolver Loan
Debt Instrument [Line Items]
Total principal						$ 0	$ 10,153,000	397,409,000
Effective interest rate (percent)						3.77%	3.79%
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility | Revolver Loan | LIBOR
Debt Instrument [Line Items]
Spread over variable rate (percent)							1.45%
Griffin Capital Essential Asset REIT, Inc. [Member] | Fixed and Variable Rate Debt
Debt Instrument [Line Items]
Weighted average interest rate						3.70%	3.53%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages
Debt Instrument [Line Items]
Total principal						$ 648,776,000	$ 672,626,000	345,934,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Plainfield Mortgage Loan [Member]
Debt Instrument [Line Items]
Total principal							$ 0	18,932,000
Contractual stated interest rate (percent)							0.00%
Effective interest rate (percent)							0.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | TW Telecom Loan
Debt Instrument [Line Items]
Total principal						$ 0	$ 19,169,000	20,353,000
Effective interest rate (percent)						0.00%	4.04%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | TW Telecom Loan | LIBOR
Debt Instrument [Line Items]
Spread over variable rate (percent)							2.45%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Bank of America loan
Debt Instrument [Line Items]
Total principal						$ 21,340,000	$ 21,694,000	22,149,000
Contractual stated interest rate (percent)						4.18%	4.175%
Effective interest rate (percent)						4.60%	4.59%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Midland Mortgage Loan
Debt Instrument [Line Items]
Total principal						$ 102,753,000	$ 104,197,000	105,600,000
Contractual stated interest rate (percent)						3.94%	3.94%
Effective interest rate (percent)						4.12%	4.08%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Emporia Partners loan
Debt Instrument [Line Items]
Total principal						$ 2,662,000	$ 2,978,000	3,377,000
Contractual stated interest rate (percent)						5.88%	5.88%
Effective interest rate (percent)						5.96%	5.96%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | BofA loan
Debt Instrument [Line Items]
Total principal						$ 22,309,000	$ 22,961,000	23,786,000
Contractual stated interest rate (percent)						6.08%	6.08%
Effective interest rate (percent)						5.16%	5.22%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Highway 94 loan
Debt Instrument [Line Items]
Total principal						$ 16,714,000	$ 17,352,000	18,175,000
Contractual stated interest rate (percent)						3.75%	3.75%
Effective interest rate (percent)						4.65%	4.63%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Bank of America loan
Debt Instrument [Line Items]
Total principal						$ 375,000,000	$ 375,000,000	0
Contractual stated interest rate (percent)			3.77%			3.77%	3.77%
Effective interest rate (percent)						3.91%	3.90%
Debt Instrument, Term			10 years			10 years
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | AIG Loan
Debt Instrument [Line Items]
Total principal						$ 107,998,000	$ 109,275,000	110,640,000
Contractual stated interest rate (percent)						4.96%	4.96%
Effective interest rate (percent)						5.07%	5.07%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Ace Hardware Mortgage Loan [Member]
Debt Instrument [Line Items]
Total principal							$ 0	$ 22,922,000
Contractual stated interest rate (percent)							0.00%
Spread over variable rate (percent)								5.00%
Effective interest rate (percent)							0.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Fixed Rate Debt
Debt Instrument [Line Items]
Weighted average interest rate						3.75%	3.54%
Interest Rate Swap
Debt Instrument [Line Items]
Derivative, Notional Amount						$ 100,000,000	$ 200,000,000		$ 100,000,000	$ 100,000,000
Interest Rate Swap | Griffin Capital Essential Asset REIT, Inc. [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount						$ 425,000,000	$ 725,000,000

Debt - Narrative (Details)

Debt - Narrative (Details)	Jun. 28, 2018USD ($)	Apr. 27, 2018USD ($)entityproperty	Mar. 31, 2018	Sep. 29, 2017USD ($)	Oct. 22, 2015USD ($)entity	Jul. 20, 2015USD ($)	Sep. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Sep. 30, 2018USD ($)property	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Nov. 22, 2016USD ($)	Mar. 29, 2016USD ($)	Aug. 11, 2015USD ($)	Dec. 12, 2014USD ($)
Debt Instrument [Line Items]
Weighted average interest rate									3.81%		3.13%
Number of Wholly Owned Special Purpose Entities | entity		4			6
Number of Properties Owned by Special Purpose Entity | property		4
Long-term debt									$ 481,573,000		$ 481,848,000	$ 456,472,000
Repayments of Lines of Credit									357,673,000	$ 0	0	55,000,000	$ 147,492,000
Proceeds from Lines of Credit									0	14,300,000	24,300,000	249,900,000	286,050,000
Total principal									490,055,000		484,728,000	460,428,000
Revolving Credit Facility | Key Bank Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 550,000,000													$ 550,000,000		$ 410,000,000	$ 250,000,000
Initial debt instrument term	4 years
Credit facility borrowing capacity	$ 1,250,000,000																$ 1,250,000,000
Line Of Credit Facility, Extension Term	1 year
Line of Credit Facility, Remaining Borrowing Capacity									$ 214,700,000		$ 143,100,000
Debt Instrument, Covenant, Minimum Number of Pool Properties | property									15
Debt Instrument, Covenant, Maximum Aggregate Pool Value Contributed by Single Pool Property									15.00%
Debt Instrument, Covenant, Maximum Aggregate Pool Value to be Contributed byPool Properties Subject to ground Leases									15.00%
Debt Instrument, Covenant, Maximum Aggregate Pool Value to be Contributed by Pool Properties Under Development									20.00%
Debt Instrument, Covenant, Minimum Leasing Percentage of All Pool Properties									90.00%
Debt Instrument, Covenant, Asset Pool Leverage Ratio									60.00%
Debt Instrument, Covenant, Asset Pool Debt Service Coverage Ratio									135.00%
Repayments of Lines of Credit		$ 249,800,000
Number of Wholly Owned Special Purpose Entities Released From Obligation | entity		4
Revolving Credit Facility | Key Bank Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 200,000,000
Initial debt instrument term	5 years
Term Loan [Member] | BofA / Key Bank Loan [Member]
Debt Instrument [Line Items]
Initial debt instrument term		10 years
Amount borrowed		$ 250,000,000
Contractual stated interest rate (percent)		4.32%
Period for written notice		30 days
Notes Payable, Other Payables [Member] | AIG Loan
Debt Instrument [Line Items]
Effective interest rate (percent)											4.22%
Initial debt instrument term					10 years						10 years
Contractual stated interest rate (percent)					4.15%						4.15%
Period for written notice					30 days
Long-term debt					$ 127,000,000
Debt Instrument, Payment Terms, Duration Requiring Monthly Payments of Interest Only					5 years						5 years
Total principal											$ 126,970,000	$ 126,970,000
Line of Credit | Key Bank Credit Facility [Member]
Debt Instrument [Line Items]
Weighted average interest rate											2.92%
Effective interest rate (percent)									3.65%		3.32%
Initial debt instrument term									4 years		4 years	4 years
Contractual stated interest rate (percent)											2.87%
Line Of Credit Facility, Extension Term									1 year		1 year	1 year
Total principal									$ 85,000		$ 357,758,000	$ 333,458,000
Mortgages
Debt Instrument [Line Items]
Total principal									$ 376,970,000		126,970,000
Mortgages | BofA / Key Bank Loan [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)									4.36%
Contractual stated interest rate (percent)									4.32%
Total principal									$ 250,000,000		0
Mortgages | AIG Loan
Debt Instrument [Line Items]
Effective interest rate (percent)									4.22%
Contractual stated interest rate (percent)									4.15%
Total principal									$ 126,970,000		$ 126,970,000
LIBOR | Line of Credit | Key Bank Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate			1.50%						1.30%		1.50%
Griffin Capital Essential Asset REIT, Inc. [Member]
Debt Instrument [Line Items]
Derivative notional amount									$ 1,150,000,000
Long-term debt									1,354,350,000		$ 1,386,084,000	1,447,535,000
Repayments of Lines of Credit									106,253,000	294,054,000	41,493,000	35,954,000	31,407,000
Proceeds from Lines of Credit									96,100,000	$ 44,000,000	54,000,000	55,100,000	481,653,000
Total principal									$ 1,363,776,000		1,397,779,000	1,458,343,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Plainfield Mortgage Loan [Member]
Debt Instrument [Line Items]
Repayments of Debt							$ 18,700,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolver Loan, July 2015 [Member]
Debt Instrument [Line Items]
Repayments of Lines of Credit											344,100,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Line of Credit | Unsecured Credit Facility (July 2015)
Debt Instrument [Line Items]
Credit facility borrowing capacity						$ 1,140,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Repayments of Lines of Credit											$ 0	0	$ 173,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility | Unsecured Credit Facility (July 2015)
Debt Instrument [Line Items]
Effective interest rate (percent)									3.89%		3.19%
Initial debt instrument term						4 years
Debt instrument extended term						1 year
Credit facility borrowing capacity						$ 500,000,000
Maximum increment to borrowing capacity available under accordion feature						860,000,000
Minimum increments allowed under accordion feature						50,000,000
Maximum borrowing capacity available under accordion feature						$ 2,000,000,000
Total principal									$ 715,000,000		$ 715,000,000	715,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Revolving Credit Facility | Revolver Loan
Debt Instrument [Line Items]
Effective interest rate (percent)									3.77%		3.79%
Total principal									$ 0		$ 10,153,000	397,409,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Fixed and Variable Rate Debt
Debt Instrument [Line Items]
Weighted average interest rate									3.70%		3.53%
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages
Debt Instrument [Line Items]
Total principal									$ 648,776,000		$ 672,626,000	345,934,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | TW Telecom Loan [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)									0.00%		4.04%
Total principal									$ 0		$ 19,169,000	20,353,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Bank of America loan
Debt Instrument [Line Items]
Effective interest rate (percent)									3.91%		3.90%
Initial debt instrument term				10 years					10 years
Amount borrowed				$ 375,000,000
Contractual stated interest rate (percent)				3.77%					3.77%		3.77%
Debt Instrument, Prepayment Condition, Prior Notice Required				30 days
Payments of Debt Issuance Costs				$ 3,000,000
Total principal									$ 375,000,000		$ 375,000,000	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | AIG Loan
Debt Instrument [Line Items]
Effective interest rate (percent)									5.07%		5.07%
Contractual stated interest rate (percent)									4.96%		4.96%
Total principal									$ 107,998,000		$ 109,275,000	110,640,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Plainfield Mortgage Loan [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)											0.00%
Contractual stated interest rate (percent)											0.00%
Total principal											$ 0	$ 18,932,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Unsecured Debt
Debt Instrument [Line Items]
Proceeds from Lines of Credit							$ 21,000,000	$ 23,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Unsecured Debt | Unsecured Credit Facility (July 2015)
Debt Instrument [Line Items]
Initial debt instrument term						5 years
Credit facility borrowing capacity						$ 640,000,000
Repayments of Debt				$ 344,100,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Unsecured Debt | Increase Agreement
Debt Instrument [Line Items]
Credit facility borrowing capacity															$ 715,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Fixed Rate Debt
Debt Instrument [Line Items]
Weighted average interest rate									3.75%		3.54%
Griffin Capital Essential Asset REIT, Inc. [Member] | LIBOR
Debt Instrument [Line Items]
Effective interest rate (percent)									2.11%		1.56%
Griffin Capital Essential Asset REIT, Inc. [Member] | LIBOR | Revolving Credit Facility | Unsecured Credit Facility (July 2015)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate											1.40%
Griffin Capital Essential Asset REIT, Inc. [Member] | LIBOR | Revolving Credit Facility | Revolver Loan
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate											1.45%
Griffin Capital Essential Asset REIT, Inc. [Member] | LIBOR | Mortgages | TW Telecom Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate											2.45%
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Debt Instrument [Line Items]
Derivative notional amount									$ 425,000,000		$ 725,000,000

Debt Debt - Maturity (Details)

Debt Debt - Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		$ 0
Long-term Debt, Maturities, Repayments of Principal in Year Two		357,758
Long-term Debt, Maturities, Repayments of Principal in Year Three		0
Long-term Debt, Maturities, Repayments of Principal in Year Four		2,178
Long-term Debt, Maturities, Repayments of Principal in Year Five		2,271
Long-term Debt, Maturities, Repayments of Principal after Year Five		122,521
Total principal	$ 490,055	484,728	$ 460,428
Debt Issuance Costs, Net	(8,482)	(2,880)	(3,956)
Debt, net	481,573	481,848	456,472
Griffin Capital Essential Asset REIT, Inc. [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		7,132
Long-term Debt, Maturities, Repayments of Principal in Year Two		24,879
Long-term Debt, Maturities, Repayments of Principal in Year Three		732,034
Long-term Debt, Maturities, Repayments of Principal in Year Four		7,211
Long-term Debt, Maturities, Repayments of Principal in Year Five		7,556
Long-term Debt, Maturities, Repayments of Principal after Year Five		618,967
Total principal	1,363,776	1,397,779	1,458,343
Debt Instrument, Unamortized Discount (Premium), Net		(281)
Debt Issuance Costs, Net		(11,414)
Debt, net	$ 1,354,350	$ 1,386,084	$ 1,447,535

Interest Rate Contracts - Narra

Interest Rate Contracts - Narrative (Details)	Aug. 31, 2018USD ($)	Apr. 30, 2018USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Nov. 01, 2017USD ($)	Dec. 31, 2016USD ($)	Apr. 01, 2016USD ($)	Feb. 25, 2016USD ($)	Jul. 09, 2015contract
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ 300,000	$ (1,000,000)
Derivative Asset			310,000	1,032,000		$ 996,000
Derivative Asset, Notional Amount				200,000,000		100,000,000
Interest Rate Swap
Derivative [Line Items]
Derivative Asset				967,000		996,000
Derivative notional amount			100,000,000	200,000,000			$ 100,000,000	$ 100,000,000
Collateral posted			0	0
Derivative Asset, Notional Amount				100,000,000		100,000,000
Griffin Capital Essential Asset REIT, Inc. [Member]
Derivative [Line Items]
Derivative notional amount			1,150,000,000
Income expected to be recognized in earnings in next 12 months			3,900,000			(800,000)
Fair value of interest rate swap in a net liability position			10,892,000	3,713,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative, Number of Instruments Held | contract									3
Fair value of interest rate swap in a net liability position				3,713,000		(3,101,000)
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July 1, 2020, $425,000 Notional Amount
Derivative [Line Items]
Derivative notional amount	$ 425,000,000
Derivative contract term	5 years
Recurring basis | Interest Rate Swap
Derivative [Line Items]
Derivative Asset			310,000	1,032,000		996,000
Recurring basis | Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset			10,892,000	3,713,000
Recurring basis | Level 2 | Interest Rate Swap
Derivative [Line Items]
Derivative Asset			310,000	1,032,000		996,000
Recurring basis | Level 2 | Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset			10,892,000	3,713,000
Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset			$ 0	65,000		0
Derivative Asset, Notional Amount				$ 100,000,000		$ 0
Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative notional amount					$ 100,000,000
Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Recurring basis | Level 2 | Interest Rate Swap
Derivative [Line Items]
Fair value of interest rate swap in a net liability position					9,000
Derivative Asset, Notional Amount					$ 100,000,000
Cash Flow Hedging | Swap [Member]
Derivative [Line Items]
Derivative notional amount		$ 100,000,000
Proceeds from Derivative Instrument, Investing Activities		$ 100,000

Interest Rate Contracts - Summa

Interest Rate Contracts - Summary of Interest Rate Swaps (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017	Nov. 01, 2017	Sep. 30, 2017	Dec. 31, 2016	Apr. 01, 2016	Feb. 25, 2016
Derivative [Line Items]
Derivative Asset	$ 310,000	$ 1,032,000			$ 996,000
Derivative Asset, Notional Amount		200,000,000			100,000,000
Interest Rate Swap
Derivative [Line Items]
Derivative notional amount	100,000,000	200,000,000				$ 100,000,000	$ 100,000,000
Derivative Asset		967,000			996,000
Derivative Asset, Notional Amount		100,000,000			100,000,000
Griffin Capital Essential Asset REIT, Inc. [Member]
Derivative [Line Items]
Derivative notional amount	1,150,000,000
Fair value of interest rate swap in a net asset (liability) position	10,892,000	3,713,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July 9, 2015
Derivative [Line Items]
Derivative notional amount	$ 425,000,000
Interest Strike Rate	1.69%			1.69%
Fair value of interest rate swap in a net asset (liability) position	$ 8,016,000	3,255,000			(1,630,000)
Derivative Liability, Notional Amount		425,000			425,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date January 1, 2016
Derivative [Line Items]
Derivative notional amount	$ 300,000,000
Interest Strike Rate	1.32%			1.32%
Fair value of interest rate swap in a net asset (liability) position	$ 0	458,000			(907,000)
Derivative Liability, Notional Amount		300,000			300,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July 1, 2020
Derivative [Line Items]
Derivative notional amount	$ 125,000,000
Interest Strike Rate	2.82%
Fair value of interest rate swap in a net asset (liability) position	$ 903,000	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July 1, 2020
Derivative [Line Items]
Derivative notional amount	$ 100,000,000
Interest Strike Rate	2.82%
Fair value of interest rate swap in a net asset (liability) position	$ 697,000	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July 1, 2020
Derivative [Line Items]
Derivative notional amount	$ 100,000,000
Interest Strike Rate	2.83%
Fair value of interest rate swap in a net asset (liability) position	$ 677,000	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July 1, 2020
Derivative [Line Items]
Derivative notional amount	$ 100,000,000
Interest Strike Rate	2.84%
Fair value of interest rate swap in a net asset (liability) position	$ 599,000	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap Effective Date July, 1 2016
Derivative [Line Items]
Interest Strike Rate				1.50%
Fair value of interest rate swap in a net asset (liability) position		0			(564,000)
Derivative Liability, Notional Amount		0			100,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Fair value of interest rate swap in a net asset (liability) position		3,713,000			(3,101,000)
Derivative Liability, Notional Amount		725,000			825,000
Sponsor [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset	310,000	967,000
Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset	$ 0	65,000			0
Derivative Asset, Notional Amount		$ 100,000,000			0
Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative notional amount			$ 100,000,000
Level 2 | Interest Rate Swap
Derivative [Line Items]
Interest Strike Rate	0.74%	0.74%
Level 2 | Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Interest Rate Swap
Derivative [Line Items]
Interest Strike Rate	1.50%	1.50%
Recurring basis | Interest Rate Swap
Derivative [Line Items]
Derivative Asset	$ 310,000	$ 1,032,000			996,000
Recurring basis | Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset	10,892,000	3,713,000
Recurring basis | Level 2 | Interest Rate Swap
Derivative [Line Items]
Derivative Asset	310,000	1,032,000			$ 996,000
Recurring basis | Level 2 | Griffin Capital Essential Asset REIT, Inc. [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset	$ 10,892,000	$ 3,713,000
Recurring basis | Level 2 | Griffin Capital Essential Asset Operating Partnership, L.P. [Member] | Interest Rate Swap
Derivative [Line Items]
Fair value of interest rate swap in a net asset (liability) position			9,000
Derivative Asset, Notional Amount			$ 100,000,000

Interest Rate Contracts - Impac

Interest Rate Contracts - Impact of Interest Rate Swap on Consolidated Statements of Operation (Details) - Interest Rate Swap - Cash Flow Hedging - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax			$ 428	$ 662
Amount of (gain) loss recognized in AOCI on derivatives	$ (281)	$ (190)
Amount of gain (loss) reclassified from AOCI into earnings under “Interest expense”	922	207
Total interest expense presented in the consolidated statement of operations in which the effects of cash flow hedges are recorded	14,775	11,445
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net			(319)	179
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net			(80)	155
Griffin Capital Essential Asset REIT, Inc. [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax			(3,035)	6,253
Amount of (gain) loss recognized in AOCI on derivatives	(8,458)	(142)
Amount of gain (loss) reclassified from AOCI into earnings under “Interest expense”	1,182	(3,330)
Total interest expense presented in the consolidated statement of operations in which the effects of cash flow hedges are recorded	$ 41,251	$ 37,232
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net			(3,856)	8,286
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net			$ (19)	$ (70)

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Payable And Accrued Liabilities [Line Items]
Real estate taxes payable	$ 3,633	$ 3,490	$ 2,678
Advance Rent	4,866	4,304	9,484
Deferred Leasing Commissions	1,900	3,783	3,783
Interest Payable, Current	2,661	3,013	1,716
Redemptions Payable, Current	6,671	2,181
Other liabilities	2,034	3,132
Other liabilities		5,313	3,866
Total	21,765	19,903	21,527
Griffin Capital Essential Asset REIT, Inc. [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Prepaid rent	14,543	16,138
Real estate taxes payable	25,666	21,087
Prepaid rent		16,312	16,799
Real estate taxes payable		21,317	24,585
Interest payable	9,270	7,924	7,606
Interest rate swap liability		0	3,101
Other liabilities	25,455	18,457
Other liabilities		18,580	12,914
Total	$ 74,934	$ 63,606	$ 65,005

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 310	$ 1,032	$ 996
Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		967	996
Recurring basis | Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	310	1,032	996
Recurring basis | Interest Rate Swap | Quoted Prices in Active Markets for Identical Assets and Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0	0
Recurring basis | Interest Rate Swap | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	310	1,032	996
Recurring basis | Interest Rate Swap | Significant Unobservable Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Recurring basis | Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	10,892	3,713
Derivative liabilities			(3,101)
Griffin Capital Essential Asset REIT, Inc. [Member] | Recurring basis | Interest Rate Swap | Quoted Prices in Active Markets for Identical Assets and Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities			0
Griffin Capital Essential Asset REIT, Inc. [Member] | Recurring basis | Interest Rate Swap | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	10,892	3,713
Derivative liabilities			(3,101)
Griffin Capital Essential Asset REIT, Inc. [Member] | Recurring basis | Interest Rate Swap | Significant Unobservable Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 0	$ 0
Derivative liabilities			$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details)	9 Months Ended
	Sep. 30, 2018loan
Griffin Capital Essential Asset REIT, Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of mortgage loans (in loan)	2

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	$ 490,055	$ 484,728	$ 460,428
Notes Payable, Other Payables [Member] | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value		126,970	126,970
Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	376,970	126,970
Mortgages | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	126,970	126,970
Fair Value | Notes Payable, Other Payables [Member] | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		122,928	120,322
Fair Value | Mortgages | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	119,338	122,928
Reported Value Measurement [Member] | Notes Payable, Other Payables [Member] | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		126,970	126,970
Reported Value Measurement [Member] | Mortgages | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	126,970
Griffin Capital Essential Asset REIT, Inc. [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	1,363,776	1,397,779	1,458,343
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	648,776	672,626	345,934
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	107,998	109,275	110,640
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | Highway 94 loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	16,714	17,352	18,175
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | BofA loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	375,000	375,000	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Mortgages | BofA loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	22,309	22,961	23,786
Griffin Capital Essential Asset REIT, Inc. [Member] | Fair Value | Mortgages | AIG Loan | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		113,715	113,052
Griffin Capital Essential Asset REIT, Inc. [Member] | Fair Value | Mortgages | Highway 94 loan | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	15,637	16,484	17,073
Griffin Capital Essential Asset REIT, Inc. [Member] | Fair Value | Mortgages | BofA loan | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	$ 361,602	377,289
Griffin Capital Essential Asset REIT, Inc. [Member] | Fair Value | Mortgages | BofA loan | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		23,851	24,349
Griffin Capital Essential Asset REIT, Inc. [Member] | Reported Value Measurement [Member] | Mortgages | AIG Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		109,275	110,640
Griffin Capital Essential Asset REIT, Inc. [Member] | Reported Value Measurement [Member] | Mortgages | Highway 94 loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		17,352	18,175
Griffin Capital Essential Asset REIT, Inc. [Member] | Reported Value Measurement [Member] | Mortgages | BofA loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		$ 22,961	$ 23,786

Equity - Narrative (Details)

Equity - Narrative (Details)	Jun. 14, 2017$ / sharesshares	Apr. 06, 2017shares	Jun. 12, 2014$ / shares	Mar. 03, 2014shares	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2018USD ($)shares	Sep. 30, 2017$ / sharesshares	Mar. 31, 2017shares	Sep. 30, 2018USD ($)vote$ / sharesshares	Sep. 30, 2017$ / sharesshares	Dec. 31, 2017USD ($)voteredemption$ / sharesshares	Dec. 31, 2016USD ($)redemption$ / sharesshares	Dec. 31, 2017USD ($)redemption$ / sharesshares	Dec. 31, 2017USD ($)redemption$ / sharesshares	Sep. 30, 2018USD ($)$ / sharesshares	Dec. 31, 2014USD ($)	Jul. 05, 2018	Sep. 20, 2017USD ($)	Jun. 09, 2017USD ($)	Sep. 22, 2015USD ($)	Jul. 31, 2014USD ($)
Class of Stock [Line Items]
Value of shares to be registered																					$ 2,200,000,000
Percentage of Organizational and Offering Costs Limit									15.00%		15.00%
Common Equity
Number of shares outstanding (in shares) | shares					77,660,266	77,660,266			77,660,266		77,175,283	70,939,647	77,175,283	77,175,283	77,660,266
Value of shares redeemed									$ 5,292,000
Stock redeemed during period (in shares) | shares									2,791,262		790,941
Noncontrolling Interests
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum											10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | shares											10,000,000		10,000,000	10,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant | shares											7,717,528		7,717,528	7,717,528
Days Required for Reimburse Excess Amounts									60 days		60 days
Organizational Costs As A Percentage Of Gross Offering Proceeds									33.30%		81.00%
Distributions Reinvestment Plan, Amendment or Termination, Written Notice Required									10 days
Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests					$ 37,401,000	$ 37,401,000			$ 37,401,000		$ 32,405,000	$ 16,930,000	$ 32,405,000	$ 32,405,000	$ 37,401,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term											10 years
Number of Votes Entitled per_Share | vote									1		1
Due to affiliates					$ 18,988,000	$ 18,988,000			$ 18,988,000		$ 16,896,000	$ 22,481,000	$ 16,896,000	$ 16,896,000	$ 18,988,000
Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period											10 years
Common Equity
Number of shares outstanding (in shares) | shares					166,253,534	166,253,534			166,253,534		170,906,111	176,032,871	170,906,111	170,906,111	166,253,534
Redemptions payable					$ 6,653,000	$ 6,653,000			$ 6,653,000		$ 20,382,000	$ 11,565,000	$ 20,382,000	$ 20,382,000	$ 6,653,000
Share redemption requests in excess of annual limitation					$ 32,400,000	$ 32,400,000			$ 32,400,000						$ 32,400,000
Noncontrolling Interests
Percentage of noncontrolling interests based on total shares (percent)					3.62%	3.62%			3.62%		4.00%		4.00%	4.00%	3.62%
Percentage of noncontrolling interests based on weighted average shares outstanding (percent)					3.58%	3.58%			3.58%						3.58%
Partnership unit exchange (in shares) | shares									1		1
Number of limited partnership units related to redemption requests (in shares) | shares									0
Limited Partners' Capital Account, Units Issued in Exchange for Property | shares											6,600,000
Limited Partners' Capital Account, Units Issued | shares											100,000		100,000	100,000
Number of Redemption Requests | redemption											0	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum											10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | shares											10,000,000		10,000,000	10,000,000
Due to affiliates					$ 4,018,000	$ 4,018,000			$ 4,018,000		$ 3,535,000	$ 2,719,000	$ 3,535,000	$ 3,535,000	$ 4,018,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Affiliated Entity
Noncontrolling Interests
Operating Partnership issued in exchange for certain properties									6,600,000
Unaffiliated Entity
Noncontrolling Interests
Operating Partnership issued in exchange for certain properties									100,000
Common Stock Subject to Mandatory Redemption [Member]
Noncontrolling Interests
Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests											32,400,000		32,400,000	32,400,000
Share Redemption Program
Common Equity
Value of shares redeemed									$ 12,200,000		$ 5,700,000	$ 1,600,000	$ 7,400,000
Stock Redeemed or Called During Period, Weighted Average Price per Share | $ / shares					$ 9.65		$ 9.06		$ 9.36	$ 9.18	$ 9.21	$ 9.72	$ 9.32
Minimum holding period for stock to be redeemed from stockholder by the Company											1 year
Minimum Redemption Percentage												25.00%
Maximum redemption percentage of weighted average shares outstanding											5.00%
Minimum ownership balance (shares)											$ 2,500		$ 2,500	$ 2,500
Percentage of Net Asset Value of shares (percent)											100.00%		100.00%	100.00%
Stock redeemed during period (in shares) | shares					585,525		146,083		1,306,834	413,842	623,499	167,442	790,941
Share Redemption Program | Griffin Capital Essential Asset REIT, Inc. [Member]
Common Equity
Period for written notice											30 days
Value of shares redeemed									$ 76,900,000		$ 98,900,000	$ 41,400,000
Redemptions payable					$ 6,700,000	6,700,000			$ 6,700,000		$ 20,400,000		$ 20,400,000	$ 20,400,000	6,700,000
Maximum redemption percentage of weighted average shares outstanding									5.00%		5.00%
Minimum ownership balance (shares)					$ 2,500	$ 2,500			$ 2,500		$ 2,500		$ 2,500	$ 2,500	$ 2,500
Percentage of Net Asset Value of shares (percent)					95.00%	95.00%			95.00%		95.00%		95.00%	95.00%	95.00%
Repurchase percentage of Net Asset Value of shares (percent)					100.00%	100.00%			100.00%		100.00%		100.00%	100.00%	100.00%
Stock redeemed during period (in shares) | shares					1,311,582		2,936,150		8,013,521	6,155,290	9,931,245	4,164,955
Weighted average price per share (in dollars per share) | $ / shares					$ 9.63		$ 9.97		$ 9.60	$ 9.98	$ 9.96	$ 9.95
Share Redemption Program | Common Stock
Common Equity
Value of shares redeemed															$ 19,600,000
Stock redeemed during period (in shares) | shares															2,097,775
Weighted average price per share (in dollars per share) | $ / shares															$ 9.34
Share Redemption Program | Common Stock | Griffin Capital Essential Asset REIT, Inc. [Member]
Common Equity
Value of shares redeemed									$ 234,600,000		$ 157,700,000	$ 58,800,000		$ 157,700,000	$ 234,600,000
Redemptions payable					$ 6,700,000	$ 6,700,000			$ 6,700,000						$ 6,700,000
Minimum holding period for stock to be redeemed from stockholder by the Company									1 year
Maximum redemption percentage of weighted average shares outstanding									5.00%
Redemption requests received (shares) | shares					4,083,881		3,878,396
Share redemption requests in excess of annual limit (shares) | shares					3,401,249		104,999
Percentage of shares requested that were redeemed (percent)					16.70%		97.00%
Stock redeemed during period (in shares) | shares														15,849,898	23,863,419
Weighted average price per share (in dollars per share) | $ / shares							$ 9.92							$ 9.95	$ 9.83
Share Repurchase Program, Redemption Requests Satisfied, Percent							95.00%
Common Stock Subject to Redemption											$ 20,400,000	11,600,000	$ 20,400,000	$ 20,400,000
New Share Redemption Program [Member]
Common Equity
Value of shares redeemed															$ 6,700,000
Stock Redeemed or Called During Period, Weighted Average Price per Share | $ / shares					$ 9.62		$ 0		$ 9.62	$ 0
Minimum holding period for stock to be redeemed from stockholder by the Company									1 year		1 year
Minimum ownership balance (shares)					$ 2,500	$ 2,500			$ 2,500						$ 2,500
Percentage of Net Asset Value of shares (percent)					100.00%	100.00%			100.00%						100.00%		100.00%
Stock redeemed during period (in shares) | shares					693,487	693,487	0		693,487	0
Weighted average price per share (in dollars per share) | $ / shares															$ 9.62
Noncontrolling Interests
Temporary Equity, Carrying Amount, Including Portion Attributable to Noncontrolling Interests					$ 37,400,000	$ 37,400,000			$ 37,400,000						$ 37,400,000
Share Redemption Program, Quarterly Cap, Percentage of Net Asset Value of Outstanding Shares									5.00%		5.00%
Share Redemption Program, Quarterly Cap											$ 0		0	0
Follow-on Offering [Member]
Class of Stock [Line Items]
Value of shares to be registered																		$ 2,200,000,000
Primary Offering [Member]
Class of Stock [Line Items]
Value of shares to be registered																		2,000,000,000
Private Placement | Griffin Capital Essential Asset REIT, Inc. [Member]
Common Equity
Proceeds from issuance of private placement									$ 1,500,000,000		$ 1,500,000,000					$ 1,300,000,000
IPO [Member]
Class of Stock [Line Items]
Value of shares to be registered																					2,000,000,000
IPO [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Common Equity
Period for written notice									10 days		10 days
IPO [Member] | Share Redemption Program
Common Equity
Minimum holding period for stock to be redeemed from stockholder by the Company									4 years		4 years
IPO [Member] | New Share Redemption Program [Member]
Common Equity
Minimum holding period for stock to be redeemed from stockholder by the Company									4 years		4 years
Distribution Reinvestment Plan
Class of Stock [Line Items]
Common Stock Offering, Registration Statement, Shares | shares		3,000,000
Equity offering, termination notice period		10 days
Value of shares to be registered																		200,000,000
Noncontrolling Interests
Shares Tendered For Redemption, Value					6,700,000	6,700,000			$ 6,700,000		$ 2,200,000		2,200,000	2,200,000	6,700,000
Common Stock Approved under Common Stock Distribution Reinvestment Plan																		$ 200,000,000			$ 200,000,000
Distribution Reinvestment Plan | Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Equity offering, termination notice period									10 days		10 days
Value of shares to be registered																			$ 10,000,000	$ 100,000,000
Common Equity
Common stock issued					245,600,000	245,600,000			$ 245,600,000		$ 211,900,000	$ 162,400,000	211,900,000	211,900,000	245,600,000
Maximum | Share Redemption Program | Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Redemption Percentage Weighted Average Shares Outstanding											5.00%
Restricted Stock [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Noncontrolling Interests
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares			$ 10.28
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares												$ 10.40
Director [Member] | Restricted Stock [Member]
Noncontrolling Interests
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares	7,000							15,000			36,000
Director [Member] | Restricted Stock [Member] | Griffin Capital Essential Asset REIT, Inc. [Member]
Noncontrolling Interests
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares	7,000			5,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized | shares				1,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 10.44
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | shares											13,000
Contingent Advisor Payment Holdback - Organization and Offering Expenses [Member]
Noncontrolling Interests
Due from Related Parties											$ 100,000	$ 5,400,000	100,000	100,000
Cumulative Organizational Costs Private and Public Offerings					510,000	510,000			510,000		359,000		359,000	359,000	510,000
Due to affiliates					1,305,000	1,305,000			1,305,000		192,000	$ 0	192,000	192,000	1,305,000
Organizational and Offering Costs Incurred [Member] | IPO [Member]
Noncontrolling Interests
Due from Related Parties											76,000,000		76,000,000	76,000,000
Cumulative Organizational Costs Private and Public Offerings					3,300,000	3,300,000			3,300,000						3,300,000
Proceeds from Issuance or Sale of Equity									10,000,000
Pro Forma [Member] | Contingent Advisor Payment Holdback - Organization and Offering Expenses [Member]
Noncontrolling Interests
Due from Related Parties					1,800,000	1,800,000			1,800,000		1,700,000		1,700,000	1,700,000	1,800,000
Due to affiliates					1,500,000	1,500,000			1,500,000						1,500,000
Due to Affiliates [Member] | Contingent Advisor Payment Holdback - Organization and Offering Expenses [Member]
Noncontrolling Interests
Due from Related Parties					700,000	700,000			700,000		1,000,000		1,000,000	1,000,000	700,000
Other Assets [Member] | Contingent Advisor Payment Holdback - Organization and Offering Expenses [Member]
Noncontrolling Interests
Due from Related Parties					$ 1,100,000	$ 1,100,000			$ 1,100,000		$ 700,000		$ 700,000	$ 700,000	$ 1,100,000

Equity - Noncontrolling Interes

Equity - Noncontrolling Interest (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of activity for noncontrolling interests
Beginning balance	$ 76	$ 84
Distributions to noncontrolling interests	(50)	(11)	$ (11)
Other comprehensive income	(641)	108	841
Ending balance	1,208	76	84
Non- controlling Interests
Schedule of activity for noncontrolling interests
Beginning balance	76	84	98	$ 139
Distributions to noncontrolling interests	(50)	(11)	(11)	(11)
Other comprehensive income	(2)
Ending balance	1,208	76	84	98
Griffin Capital Essential Asset REIT, Inc. [Member]
Noncontrolling Interest [Line Items]
Issuance of limited partnership units			11,941	7,282
Schedule of activity for noncontrolling interests
Beginning balance	31,105
Distributions to noncontrolling interests	(3,267)	(4,369)	(4,124)	(3,150)
Allocated distributions to noncontrolling interests subject to redemption	(10)	(13)	(11)	(10)
Net income	17,275	145,777	26,197	(3,888)
Other comprehensive income	7,500	7,356	2,274	(6,560)
Ending balance	28,723	31,105
Griffin Capital Essential Asset REIT, Inc. [Member] | Non- controlling Interests
Noncontrolling Interest [Line Items]
Issuance of limited partnership units		0	11,941	7,282
Schedule of activity for noncontrolling interests
Beginning balance	31,105	30,114	21,318	17,478
Distributions to noncontrolling interests	(3,267)	(4,369)	(4,124)	(3,150)
Allocated distributions to noncontrolling interests subject to redemption	(10)	(13)	(11)	(10)
Net income	671	5,120	912	(138)
Other comprehensive income	$ 224	253	78	(144)
Ending balance		$ 31,105	$ 30,114	$ 21,318

Equity Equity - Redemption Acti

Equity Equity - Redemption Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended		24 Months Ended	57 Months Ended	67 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2017	Sep. 30, 2018
Class of Stock [Line Items]
Redemption Price Within One Year, Percent						0.00%
Stock redeemed during period (in shares)				2,791,262		790,941
Value of shares redeemed				$ 5,292
Redemption Price Year One, Percent						90.00%
Redemption Price Year Two, Percent						95.00%
Redemption Price Year Three, Percent						97.50%
Redemption Price Year Four and Greater, Percent						100.00%
Share Redemption Program
Class of Stock [Line Items]
Minimum holding period for stock to be redeemed from stockholder by the Company						1 year
Stock redeemed during period (in shares)		585,525	146,083	1,306,834	413,842	623,499	167,442	790,941
Value of shares redeemed				$ 12,200		$ 5,700	$ 1,600	$ 7,400
Stock Redeemed or Called During Period, Weighted Average Price per Share		$ 9.65	$ 9.06	$ 9.36	$ 9.18	$ 9.21	$ 9.72	$ 9.32
Share Redemption Program | Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Stock redeemed during period (in shares)		1,311,582	2,936,150	8,013,521	6,155,290	9,931,245	4,164,955
Value of shares redeemed				$ 76,900		$ 98,900	$ 41,400
Weighted average price per share (in dollars per share)		$ 9.63	$ 9.97	$ 9.60	$ 9.98	$ 9.96	$ 9.95
New Share Redemption Program [Member]
Class of Stock [Line Items]
Minimum holding period for stock to be redeemed from stockholder by the Company				1 year		1 year
Stock redeemed during period (in shares)	693,487	693,487	0	693,487	0
Value of shares redeemed										$ 6,700
Weighted average price per share (in dollars per share)										$ 9.62
Stock Redeemed or Called During Period, Weighted Average Price per Share		$ 9.62	$ 0	$ 9.62	$ 0
Share Redemption Program, Modification or Suspension, Written Notice Required				30 days
Common Stock | Share Redemption Program
Class of Stock [Line Items]
Stock redeemed during period (in shares)										2,097,775
Value of shares redeemed										$ 19,600
Weighted average price per share (in dollars per share)										$ 9.34
Common Stock | Share Redemption Program | Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Minimum holding period for stock to be redeemed from stockholder by the Company				1 year
Stock redeemed during period (in shares)									15,849,898	23,863,419
Value of shares redeemed				$ 234,600		$ 157,700	$ 58,800		$ 157,700	$ 234,600
Weighted average price per share (in dollars per share)			$ 9.92						$ 9.95	$ 9.83

Equity Equity - Distributions (

Equity Equity - Distributions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Distributions, Ordinary Income	$ 0.04	$ 0.31	$ 0.21
Distributions, Ordinary Income, Percent	7.90%	57.10%	38.60%
Distributions, Return of Capital	$ 0.51	$ 0.24	$ 0.34
Distributions, Return of Capital, Percent	92.10%	42.90%	61.40%
Distributions, Total	$ 0.55	$ 0.55	$ 0.55
Distributions, Total, Percent	100.00%	100.00%	100.00%
Griffin Capital Essential Asset REIT, Inc. [Member]
Class of Stock [Line Items]
Distributions, Ordinary Income	$ 0.40	$ 0.47	$ 0.48
Distributions, Ordinary Income, Percent	59.00%	69.00%	69.00%
Distributions, Capital Gain	$ 0.18	$ 0	$ 0
Distributions, Capital Gain, Percent	26.00%	0.00%	0.00%
Distributions, Return of Capital	$ 0.10	$ 0.21	$ 0.21
Distributions, Return of Capital, Percent	15.00%	31.00%	31.00%
Distributions, Total	$ 0.68	$ 0.68	$ 0.69
Distributions, Total, Percent	100.00%	100.00%	100.00%

Equity Equity - Shares Issued a

Equity Equity - Shares Issued and Gross Proceeds (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	(2,791,262)	(790,941)
Common Stock, Shares, Outstanding	77,660,266	77,175,283	70,939,647
Common Class T [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	0	0
Common Stock, Shares, Outstanding	226,297	4,148	0
Common Class S [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	0	0
Common Stock, Shares, Outstanding	277	268	0
Common Class D [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	0	0
Common Stock, Shares, Outstanding	19,157	268	0
Common Class I [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	0	0
Common Stock, Shares, Outstanding	803,069	267,476	0
Common Class A [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	(1,351,178)	(557,206)
Common Stock, Shares, Outstanding	25,781,325	25,995,943	25,562,982
Common Class AA [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	(1,434,491)	(233,735)
Common Stock, Shares, Outstanding	49,840,818	49,942,471	44,595,631
Common Class AAA [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	(5,593)	0
Common Stock, Shares, Outstanding	989,323	964,709	781,034
IPO [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 733,987	$ 726,557
Common stock issued (shares)	73,694,264	72,931,727
IPO [Member] | Common Class T [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 2,245	$ 41
Common stock issued (shares)	224,647	4,144
IPO [Member] | Common Class S [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 3	$ 3
Common stock issued (shares)	264	264
IPO [Member] | Common Class D [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 182	$ 3
Common stock issued (shares)	18,921	264
IPO [Member] | Common Class I [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 7,538	$ 2,493
Common stock issued (shares)	786,573	263,200
IPO [Member] | Common Class A [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 240,780	$ 240,780
Common stock issued (shares)	24,199,764	24,199,760
IPO [Member] | Common Class AA [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 474,858	$ 474,858
Common stock issued (shares)	47,562,870	47,562,870
IPO [Member] | Common Class AAA [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 8,381	$ 8,379
Common stock issued (shares)	901,225	901,225
Distribution Reinvestment Plan
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 58,376	$ 41,954
Common stock issued (shares)	6,152,779	4,440,514
Distribution Reinvestment Plan | Common Class T [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 16	$ 0
Common stock issued (shares)	1,650	4
Distribution Reinvestment Plan | Common Class S [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 0	$ 0
Common stock issued (shares)	13	4
Distribution Reinvestment Plan | Common Class D [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 2	$ 0
Common stock issued (shares)	236	4
Distribution Reinvestment Plan | Common Class I [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 158	$ 41
Common stock issued (shares)	16,496	4,276
Distribution Reinvestment Plan | Common Class A [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 25,328	$ 19,773
Common stock issued (shares)	2,669,097	2,089,748
Distribution Reinvestment Plan | Common Class AA [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 32,369	$ 21,828
Common stock issued (shares)	3,412,273	2,313,170
Distribution Reinvestment Plan | Common Class AAA [Member]
Class of Stock [Line Items]
Common Stock, Gross Proceeds Received to Date, New Issues	$ 503	$ 312
Common stock issued (shares)	53,014	33,308
Share Distribution [Member]
Class of Stock [Line Items]
Common stock issued (shares)	568,485	568,483
Share Distribution [Member] | Common Class T [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Share Distribution [Member] | Common Class S [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Share Distribution [Member] | Common Class D [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Share Distribution [Member] | Common Class I [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Share Distribution [Member] | Common Class A [Member]
Class of Stock [Line Items]
Common stock issued (shares)	263,642	263,641
Share Distribution [Member] | Common Class AA [Member]
Class of Stock [Line Items]
Common stock issued (shares)	300,166	300,166
Share Distribution [Member] | Common Class AAA [Member]
Class of Stock [Line Items]
Common stock issued (shares)	4,677	4,676
Restricted Stock Issuance [Member]
Class of Stock [Line Items]
Common stock issued (shares)	36,000	25,500
Restricted Stock Issuance [Member] | Common Class T [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Restricted Stock Issuance [Member] | Common Class S [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Restricted Stock Issuance [Member] | Common Class D [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Restricted Stock Issuance [Member] | Common Class I [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Restricted Stock Issuance [Member] | Common Class A [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Restricted Stock Issuance [Member] | Common Class AA [Member]
Class of Stock [Line Items]
Common stock issued (shares)	0	0
Restricted Stock Issuance [Member] | Common Class AAA [Member]
Class of Stock [Line Items]
Common stock issued (shares)	36,000	25,500

Equity Equity - Cumulative Offe

Equity Equity - Cumulative Offering Costs (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Due from Affiliates	$ (1,128)	$ (686)	$ 0
Contingent Advisor Payment Holdback - Organization and Offering Expenses [Member]
Class of Stock [Line Items]
Cumulative Offering Costs Private and Public Offerings	2,806	1,698
Cumulative Organizational Costs Private and Public Offerings	510	359
Organizational and Offering Costs Previously Advanced by Advisor	1,998	1,226
Payment of Offering and Organizational Cost	1,318	831
Due to Affiliate		(999)
Due from Affiliates		(677)
Organizational and Offering Costs Incurred, Net of Advisor Advances, Net Due	1,496	$ 381
Costs in Excess of Limit	$ 1,820

Noncontrolling Interest (Detail

Noncontrolling Interest (Details) - USD ($)	Feb. 16, 2018	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 11, 2014
Schedule of activity for noncontrolling interests
Beginning balance		$ 76,000	$ 84,000
Issuance of limited partnership units		1,185,000
Distributions to noncontrolling interests		(50,000)	(11,000)	$ (11,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Distributions to Redeemable Preferred Units, and Preferred Unit Redemption Charges		(431,000)	11,119,000	(6,107,000)	$ (17,277,000)
Other comprehensive income		(641,000)	108,000	841,000
Ending balance		1,208,000	76,000	84,000
Non- controlling Interests
Schedule of activity for noncontrolling interests
Beginning balance		76,000	84,000	98,000	139,000
Issuance of limited partnership units		1,185,000	0
Distributions to noncontrolling interests		(50,000)	(11,000)	(11,000)	(11,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Distributions to Redeemable Preferred Units, and Preferred Unit Redemption Charges		(1,000)	3,000	(3,000)	(30,000)
Other comprehensive income		(2,000)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest			0
Ending balance		$ 1,208,000	$ 76,000	$ 84,000	$ 98,000
Griffin Capital Essential Asset Operating Partnership, L.P. [Member]
Noncontrolling Interest [Line Items]
Limited Partners' Capital Account, Number of Common Shares That Can Be Issued for Each Partnership Unit Redeemed		1
Limited Partner Account, Redemption, Minimum Period Outstanding Required		1 year
Operating Partnership [Member]
Noncontrolling Interest [Line Items]
Percentage of noncontrolling interests based on total shares (percent)			0.03%
Limited Partner [Member] | Griffin Capital Essential Asset Operating Partnership, L.P. [Member]
Noncontrolling Interest [Line Items]
Limited Partners' Capital Account, Units Issued						20,000
Stock purchase price (usd per share)						$ 10
Limited Partner [Member] | Operating Partnership [Member]
Noncontrolling Interest [Line Items]
Limited Partners' Capital Account, Units Issued						20,000
Stock purchase price (usd per share)						$ 10
Partnership unit exchange (in shares)			1
Griffin Capital Essential Asset Advisor II, LLC [Member]
Noncontrolling Interest [Line Items]
Limited Partners' Capital Account, Units Issued	123,779
Stock purchase price (usd per share)	$ 9.57
Performance Distribution, Percentage of Allocation	50.00%
Shares Outstanding [Member] | Griffin Capital Essential Asset Operating Partnership, L.P. [Member]
Noncontrolling Interest [Line Items]
Percentage of noncontrolling interests based on total shares (percent)		0.18%
Weighted Average Shares Outstanding [Member] | Griffin Capital Essential Asset Operating Partnership, L.P. [Member]
Noncontrolling Interest [Line Items]
Percentage of noncontrolling interests based on total shares (percent)		0.16%

Perpetual Convertible Preferr_2

Perpetual Convertible Preferred Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 02, 2021	Aug. 02, 2020	Aug. 08, 2018	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Temporary Equity [Line Items]
Transaction-related expenses incurred					$ 3,660	$ 6,695
First Issuance | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Aggregate number of shares to be purchased under transaction agreement (shares)			5,000,000
Griffin Capital Essential Asset REIT, Inc. [Member]
Temporary Equity [Line Items]
Transaction-related expenses incurred					$ 4,727	$ 0	$ 0	$ 0	$ 62
Griffin Capital Essential Asset REIT, Inc. [Member] | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Preferred stock par value (usd per share)			$ 0.001
Stock purchase price (usd per share)			$ 25
Restrictive period after closing date on transferring shares or economic interest			5 years
Liquidation preference (usd per share)			$ 25
Redemption fee (percent)			1.50%
Griffin Capital Essential Asset REIT, Inc. [Member] | Preferred Stock Issuance | Forecast | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Aggregate number of shares to be purchased under transaction agreement (shares)				10,000,000
Griffin Capital Essential Asset REIT, Inc. [Member] | First Issuance | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Aggregate number of shares to be purchased under transaction agreement (shares)			5,000,000
Stock purchase price			$ 125,000
Transaction fees paid (percent)			3.50%
Transaction-related expenses incurred			$ 400
Initial annual distribution (percent)			6.55%
Anniversary period since issuance date			5 years
Redemption rights, period from issuance			5 years
Conversion rights, period from issuance			5 years
Griffin Capital Essential Asset REIT, Inc. [Member] | Secondary Issuance | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Initial annual distribution (percent)			6.55%
Anniversary period since issuance date			5 years
Conversion rights, period from issuance			5 years
Griffin Capital Essential Asset REIT, Inc. [Member] | Secondary Issuance | Forecast | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Aggregate number of shares to be purchased under transaction agreement (shares)				5,000,000
Stock purchase price				$ 125,000
Griffin Capital Essential Asset REIT, Inc. [Member] | Reset date | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Initial annual distribution (percent)			6.75%
Griffin Capital Essential Asset REIT, Inc. [Member] | Reset date | Forecast | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Initial annual distribution (percent)	8.25%	7.75%
Griffin Capital Essential Asset REIT, Inc. [Member] | Triggering event | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Redemption price per share (usd per share)			$ 25
Griffin Capital Essential Asset REIT, Inc. [Member] | Triggering event | Forecast | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Initial annual distribution (percent)	8.05%	7.55%
Griffin Capital Essential Asset REIT, Inc. [Member] | Advisor | First Issuance | Series A Cumulative Perpetual Convertible Preferred Stock
Temporary Equity [Line Items]
Transaction-related expenses to be paid			$ 200

Related Party Transactions - Sc

Related Party Transactions - Schedule of Related Parties (Details) $ in Thousands, ft² in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)ft²	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)ft²	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 20, 2017USD ($)ft²
Related Party Transaction [Line Items]
Approx. Square Feet | ft²	7.3		7.3
Real Estate Investment Property, at Cost	$ 1,182,057		$ 1,178,866	$ 1,133,055
Schedule of related party transactions
Incurred	19,051	$ 16,502	22,272	66,819	$ 47,207
Payable	$ 18,988		$ 16,896	22,481
Underwriting Compensation Percentage of Gross Proceeds Received	9.00%		9.00%
Advisor and Property Manager Fees - Acquisition Fees and Expenses [Member]
Related Party Transaction [Line Items]
Approx. Square Feet | ft²						1
Real Estate Investment Property, at Cost						$ 80,000
Schedule of related party transactions
Incurred			$ 0	6,324	11,438
Payable			0	0
Operating expenses
Schedule of related party transactions
Incurred	$ 2,168	1,677	2,336	1,622	1,911
Payable	806		658	18
Asset management fees
Schedule of related party transactions
Incurred	0	8,027	8,027	6,413	2,624
Payable	0		0	807
Property Management Fees [Member]
Schedule of related party transactions
Incurred	1,365	1,347	1,799	1,052	333
Payable	153		158	143
Acquisition fees
Schedule of related party transactions
Incurred	0	1,099	1,099	7,606	0
Payable	0		0	0
Advisor and Property Manager Fees - Performance Distribution [Member]
Schedule of related party transactions
Incurred	6,200	213	2,394	0	0
Payable	6,224		2,394	0
Advisor and Property Manager Fees - Advisory Fees [Member]
Schedule of related party transactions
Incurred	6,970	273	2,550	0	0
Payable	784		762	0
Contingent Advisor Payment Holdback - Organization and Offering Expenses [Member]
Schedule of related party transactions
Incurred	1,113	250	192	0	3,150
Payable	1,305		192	0
Other Costs Advanced by Advisor [Member]
Schedule of related party transactions
Incurred	938	604	662	304	2,598
Payable	$ 319		285	12
Advisor and Property Manager Fees - Preferred Offering Costs [Member]
Schedule of related party transactions
Incurred			0	0	375
Payable			$ 0	0
Dealer Manager Agreement [Member]
Schedule of related party transactions
Underwriting Compensation Percentage of Gross Proceeds Received	10.00%		10.00%
Advisor and Property Manager Fees - Selling Commissions [Member]
Schedule of related party transactions
Incurred	$ 66	1,127	$ 1,128	11,397	16,303
Payable	0		0	54
Advisor and Property Manager Fees - Dealer Manager Fees [Member]
Schedule of related party transactions
Incurred	11	393	393	3,949	7,303
Payable	0		0	18
Advisor and Property Manager Fees - Stockholder Servicing Fee [Member]
Schedule of related party transactions
Incurred	175	565	660	17,449	25
Payable	9,353		12,377	16,020
Advisor Advances - Organization and Offering Expenses [Member]
Schedule of related party transactions
Incurred	45	136	179	2,634	382
Payable	44		8	2,477
Contingent Advisor Payment Holdback - Dealer Manager Fees [Member]
Schedule of related party transactions
Incurred	0	791	853	8,069	765
Payable	0		62	2,932
Griffin Capital Essential Asset REIT, Inc. [Member]
Related Party Transaction [Line Items]
Real Estate Investment Property, at Cost	3,077,761		2,865,753	3,024,389
Schedule of related party transactions
Payable	4,018		3,535	2,719
Griffin Capital Essential Asset REIT, Inc. [Member] | Advisor and Property Manager Fees - Acquisition Fees and Expenses [Member]
Schedule of related party transactions
Incurred			0	1,322	35,210
Payable			0	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Operating expenses
Schedule of related party transactions
Incurred	2,630	1,983	2,652	1,525	1,608
Payable	949		670	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Asset Management Fees 2 [Member]
Schedule of related party transactions
Incurred	17,628	17,744
Payable	1,999		1,873
Griffin Capital Essential Asset REIT, Inc. [Member] | Asset management fees
Schedule of related party transactions
Incurred			23,499	23,530	19,389
Payable			1,878	1,982
Griffin Capital Essential Asset REIT, Inc. [Member] | Property Management Fees [Member]
Schedule of related party transactions
Incurred	6,992	7,466
Payable	746		725
Griffin Capital Essential Asset REIT, Inc. [Member] | Property management fees
Schedule of related party transactions
Incurred			9,782	9,740	7,622
Payable			730	737
Griffin Capital Essential Asset REIT, Inc. [Member] | Costs advanced by the Advisor
Schedule of related party transactions
Incurred	396	419	587	73	53
Payable	324		267	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Acquisition fees
Schedule of related party transactions
Incurred	5,331	0	3,791	0	0
Payable	0		0	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Leasing commissions
Schedule of related party transactions
Incurred	0	1,752	1,752	0	2,105
Payable	0		0	0
Griffin Capital Essential Asset REIT, Inc. [Member] | Costs Capitalized [Member]
Schedule of related party transactions
Incurred	32,977	29,364
Payable	4,018		3,535
Griffin Capital Essential Asset REIT, Inc. [Member] | Total, including real estate assets held for sale
Schedule of related party transactions
Incurred	33,076	29,459	44,013	36,190	66,627
Payable	4,023		3,545	2,719
Griffin Capital Essential Asset REIT, Inc. [Member] | Disposition Fees [Member]
Schedule of related party transactions
Incurred			1,950	0	$ 640
Payable			0	$ 0
Griffin Capital Essential Asset REIT, Inc. [Member] | Held-for-sale | Asset management fees
Schedule of related party transactions
Incurred	42	42
Payable	5		5
Griffin Capital Essential Asset REIT, Inc. [Member] | Held-for-sale | Property Management Fees [Member]
Schedule of related party transactions
Incurred	57	$ 53
Payable	$ 0		$ 5
Common Class AA [Member] | Dealer Manager Agreement [Member]
Schedule of related party transactions
Related Party Stockholder Servicing Fee for Issuance of Shares, Percent	4.00%		4.00%

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - USD ($) $ in Thousands	Feb. 16, 2018	Sep. 20, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Average invested assets percentage						2.00%
Operating expenses				$ 19,051	$ 16,502	$ 22,272	$ 66,819	$ 47,207
Property management fees percentage						3.00%
Gross revenue percentage						1.00%
Construction management fee percentage						5.00%
Underwriting Compensation Percentage of Gross Proceeds Received				9.00%		9.00%
Related Party Transaction, Shares Outstanding			563,440	563,440
Griffin Capital Essential Asset Advisor II, LLC [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Shares Sold		263,992
Related Party Transaction, Proceeds from Sell of Shares		$ 2,500
Advisor and Property Manager Fees - Performance Distribution [Member]
Related Party Transaction [Line Items]
Performance Distribution, Percentage Of Total Return				12.50%		12.50%
Operating expenses				$ 6,200	213	$ 2,394	0	$ 0
Performance Distribution, Hurdle Rate, Annualized Rate Of Return On Net Asset Value				5.50%		5.50%
Performance Distribution, Distribution Percentage On Excess Profits Before Threshold						100.00%
Performance Distribution, Distribution Threshold						12.50%
Performance Distribution, Distribution Percentage On Excess Profits After Threshold						12.50%
Related Party Transaction, Amounts of Transaction	$ 1,200
Reimbursement, Services Provided That Are not Entitled to Advisor Fees | Griffin Capital Essential Asset Advisor II, LLC [Member]
Related Party Transaction [Line Items]
Operating expenses				$ 600	500
Reimbursement, Services Provided That Are not Entitled to Advisor Fees | Griffin Capital Essential Asset Advisor, LLC
Related Party Transaction [Line Items]
Operating expenses						$ 700	500
Reimbursement, Reimbursable Expenses
Related Party Transaction [Line Items]
Average invested assets percentage				2.00%
Sales revenue goods percentage				25.00%		25.00%
Reimbursement, Reimbursable Expenses | Griffin Capital Essential Asset Advisor II, LLC [Member]
Related Party Transaction [Line Items]
Operating expenses				$ 70	100
Reimbursement, Reimbursable Expenses | Griffin Capital Essential Asset Advisor, LLC
Related Party Transaction [Line Items]
Operating expenses						$ 200
Dealer Manager Agreement [Member]
Related Party Transaction [Line Items]
Dealer Manager Fee Percentage						0.50%
Underwriting Compensation Percentage of Gross Proceeds Received				10.00%		10.00%
Dealer Distribution Fee [Member]
Related Party Transaction [Line Items]
Underwriting Compensation Percentage of Gross Proceeds Received				9.00%		9.00%
Griffin Capital Essential Asset REIT, Inc. [Member]
Related Party Transaction [Line Items]
Percentage of acquisition fees (percent)				2.50%		2.50%
Percent reimbursed (percent)				0.50%		0.50%
Percentage of purchase price of properties				0.60%		0.60%
Percentage of contract purchase price				6.00%		6.00%
Disposition fee, percent of contract sales price				3.00%		3.00%
Disposition fee, percent of competitive commission				50.00%		50.00%
Disposition fee, percent of aggregate contract sales price				6.00%		6.00%
Asset management fee percentage of average invested assets				0.75%		0.75%
Average invested assets percentage				2.00%		2.00%
Sales revenue goods percentage				25.00%		25.00%
Property management fees percentage				3.00%		3.00%
Gross revenue percentage				1.00%		1.00%
Construction management fee percentage				5.00%		5.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Griffin Capital Essential Asset Advisor, LLC | Executive Officer [Member]
Related Party Transaction [Line Items]
Operating expenses						$ 600	400
Griffin Capital Essential Asset REIT, Inc. [Member] | Griffin Capital Essential Asset Advisor, LLC | Officer [Member]
Related Party Transaction [Line Items]
Operating expenses						$ 200	$ 200
Griffin Capital Essential Asset REIT, Inc. [Member] | Reimbursement, Services Provided That Are not Entitled to Advisor Fees | Griffin Capital Essential Asset Advisor, LLC
Related Party Transaction [Line Items]
Operating expenses			$ 400
Griffin Capital Essential Asset REIT, Inc. [Member] | Reimbursement, Reimbursable Expenses | Griffin Capital Essential Asset Advisor, LLC
Related Party Transaction [Line Items]
Operating expenses			$ 200		$ 100
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Share of Net Sale Proceeds | Griffin Capital Essential Asset Advisor, LLC | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, minimum required cumulative, non-compounded return to shareholders, percentage				6.00%		6.00%
Compensation rate, cumulative, non-compounded return to shareholders, range one, percentage				5.00%		5.00%
Compensation rate, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range three, percentage				10.00%		10.00%
Compensation rate, cumulative, non-compounded return to shareholders, range three, percentage				15.00%		15.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Share of Net Sale Proceeds | Griffin Capital Essential Asset Advisor, LLC | Minimum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				6.00%		6.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				8.00%		8.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Share of Net Sale Proceeds | Griffin Capital Essential Asset Advisor, LLC | Maximum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				8.00%		8.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Incentive Listing Distribution | Griffin Capital Essential Asset Advisor, LLC | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, minimum required cumulative, non-compounded return to shareholders, percentage				6.00%		6.00%
Compensation rate, cumulative, non-compounded return to shareholders, range one, percentage				5.00%		5.00%
Compensation rate, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range three, percentage				10.00%		10.00%
Compensation rate, cumulative, non-compounded return to shareholders, range three, percentage				15.00%		15.00%
Compensation payable, number of trading days				30 days		30 days
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Incentive Listing Distribution | Griffin Capital Essential Asset Advisor, LLC | Minimum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				6.00%		6.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				8.00%		8.00%
Compensation payable, distribution period				7 months		7 months
Compensation payable, 30 day commencement period				6 months		6 months
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Incentive Listing Distribution | Griffin Capital Essential Asset Advisor, LLC | Maximum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				8.00%		8.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Compensation payable, distribution period				19 months		19 months
Compensation payable, 30 day commencement period				18 months		18 months
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Termination | Griffin Capital Essential Asset Advisor, LLC | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, minimum required cumulative, non-compounded return to shareholders, percentage				6.00%		6.00%
Compensation rate, cumulative, non-compounded return to shareholders, range one, percentage				5.00%		5.00%
Compensation rate, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range three, percentage				10.00%		10.00%
Compensation rate, cumulative, non-compounded return to shareholders, range three, percentage				15.00%		15.00%
Compensation payable, percent owed within first 30 days				33.33%		33.33%
Compensation payable, termination date range one				30 days		30 days
Compensation payable, percent owed at one year anniversary				33.33%		33.33%
Compensation payable, termination date range two				1 year		1 year
Compensation payable, percent owed at two year anniversary				33.33%		33.33%
Compensation payable, termination date range three				2 years		2 years
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Termination | Griffin Capital Essential Asset Advisor, LLC | Minimum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				6.00%		6.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				8.00%		8.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Termination | Griffin Capital Essential Asset Advisor, LLC | Maximum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				8.00%		8.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Extraordinary Transaction | Griffin Capital Essential Asset Advisor, LLC | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, minimum required cumulative, non-compounded return to shareholders, percentage				6.00%		6.00%
Compensation rate, cumulative, non-compounded return to shareholders, range one, percentage				5.00%		5.00%
Compensation rate, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range three, percentage				10.00%		10.00%
Compensation rate, cumulative, non-compounded return to shareholders, range three, percentage				15.00%		15.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Extraordinary Transaction | Griffin Capital Essential Asset Advisor, LLC | Minimum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				6.00%		6.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				8.00%		8.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Extraordinary Transaction | Griffin Capital Essential Asset Advisor, LLC | Maximum | Affiliated Entity
Related Party Transaction [Line Items]
Determination of compensation, cumulative, non-compounded return to shareholders, range one, percentage				8.00%		8.00%
Determination of compensation, cumulative, non-compounded return to shareholders, range two, percentage				10.00%		10.00%
Griffin Capital Essential Asset REIT, Inc. [Member] | Compensation, Subordinated Distribution Due Upon Extraordinary Transaction | Griffin Capital Corporation | Affiliated Entity
Related Party Transaction [Line Items]
Excess merger consideration, trading restriction on stock from date of receipt				1 year		1 year
Common Class T [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00274%		0.00274%
Common Class T [Member] | Dealer Manager Agreement [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00274%		0.00274%
Related Party Fee Percentage, Sales Commission On Stock Offering						3.00%
Common Class T [Member] | Dealer Distribution Fee [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00068%		0.00068%
Common Class T [Member] | Advisor Distribution Fee [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00205%		0.00205%
Common Class T [Member] | Advisory Agreement [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00342%		0.00342%
Common Class S [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00274%		0.00274%
Common Class S [Member] | Dealer Manager Agreement [Member]
Related Party Transaction [Line Items]
Related Party Fee Percentage, Sales Commission On Stock Offering						3.50%
Common Class D [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00068%		0.00068%
Common Class AA [Member] | Dealer Manager Agreement [Member]
Related Party Transaction [Line Items]
Stockholder Servicing Fee, Daily Accrual Rate				0.00274%		0.00274%
Limited Partnership Units [Member] | Advisor and Property Manager Fees - Performance Distribution [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 1,200
Related Party Transaction, Cash Election	50.00%

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Operating Leased Assets [Line Items]
2,018			$ 71,662
Remaining 2,018	$ 19,311
2,019	78,887		78,887
2,020	80,492		80,492
2,021	72,677		72,677
2,022	73,538		73,538
Thereafter	528,803		528,803
Total	853,708		906,059
Griffin Capital Essential Asset REIT, Inc. [Member]
Operating Leased Assets [Line Items]
Rent expense			400	$ 400
2,018			231,620
Remaining 2,018	61,164
2,019	226,557		210,449
2,020	204,640		188,653
2,021	191,182		174,053
2,022	182,708		164,494
Thereafter	803,849		664,226
Total	1,670,100		1,633,495
Griffin Capital Essential Asset REIT, Inc. [Member] | Ground Lease
Operating Leased Assets [Line Items]
Rent expense	1,300	$ 1,300
2,018			198
Remaining 2,018	258
2,019	1,032		198
2,020	1,032		198
2,021	1,032		198
2,022	1,072		218
Thereafter	200,446		33,631
Total	$ 204,872		$ 34,641

Declaration of Distributions (D

Declaration of Distributions (Details) - $ / shares	Sep. 12, 2018	Mar. 08, 2018	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Mar. 07, 2018	Sep. 30, 2017
Dividends Payable [Line Items]
Dividends per share paid (in usd per share)			$ 0.0015068493	$ 0.00150684932
Dividends per share declared (in usd per share)	$ 0.0015068493		0.14		$ 0.14	$ 0.42		$ 0.42
Griffin Capital Essential Asset REIT, Inc. [Member]
Dividends Payable [Line Items]
Dividends per share paid (in usd per share)			0.001901096	$ 0.001901096
Dividends per share declared (in usd per share)	$ 0.001901096		$ 0.17		$ 0.17	$ 0.51		$ 0.51
Subsequent Event
Dividends Payable [Line Items]
Dividends per share declared (in usd per share)		$ 0.00150684932
Subsequent Event | Griffin Capital Essential Asset REIT, Inc. [Member]
Dividends Payable [Line Items]
Dividends per share declared (in usd per share)							$ 0.001901096

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									9 Months Ended		12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information [Line Items]
Revenues	$ 26,713	$ 27,514	$ 27,349	$ 26,546	$ 25,972	$ 20,646	$ 16,334	$ 13,330	$ 12,502	$ 79,799	$ 79,882	$ 107,381	$ 62,812	$ 25,149
Operating Income (Loss)	4,679		6,995							14,148	20,768	26,107	4,264	(11,653)
Net income	(757)	1,531	3,099	3,365	3,124	595	(2,736)	(2,825)	(1,141)	(431)	9,588	11,119	(6,107)	(16,504)
Net Income (Loss) Attributable to Parent	$ (756)	$ 1,531	$ 3,098	$ 3,364	$ 3,123	$ 595	$ (2,735)	$ (2,824)	$ (1,140)	$ (430)	$ 9,585	$ 11,116	$ (6,104)	$ (17,247)
Earnings Per Share, Basic and Diluted	$ (0.01)	$ 0.03	$ 0.04	$ 0.04	$ 0.04	$ 0.01	$ (0.05)	$ (0.06)	$ (0.03)	$ (0.01)	$ 0.13	$ 0.15	$ (0.12)	$ (1.19)
Griffin Capital Essential Asset REIT, Inc. [Member]
Quarterly Financial Information [Line Items]
Revenues	$ 85,041	$ 81,878	$ 85,132	$ 82,772	$ 96,708	$ 84,218	$ 86,736	$ 86,588	$ 86,732	$ 251,431	$ 264,612	$ 346,490	$ 344,274	$ 292,853
Operating Income (Loss)	19,012	15,428	22,394	17,685	26,787	12,339	19,378	18,841	22,973	60,262	66,866	82,294	73,531	35,109
Net income	4,329	113,222	9,445	9,160	14,306	457	7,131	6,581	12,386	18,769	32,911	146,133	26,555	15,621
Net Income (Loss) Attributable to Parent	$ 2,854	$ 109,146	$ 9,029	$ 8,756	$ 13,726	$ 351	$ 6,795	$ 6,248	$ 11,891	$ 16,604	$ 31,511	$ 140,657	$ 25,285	$ (3,750)
Earnings Per Share, Basic and Diluted	$ 0.02	$ 0.64	$ 0.05	$ 0.05	$ 0.08	$ 0	$ 0.04	$ 0.04	$ 0.07	$ 0.10	$ 0.18	$ 0.81	$ 0.14	$ (0.02)

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 07, 2018	Nov. 02, 2018	Oct. 31, 2018	Oct. 03, 2018	Sep. 12, 2018	Mar. 08, 2018	Feb. 16, 2018	Jan. 31, 2018	Nov. 07, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Mar. 07, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Oct. 24, 2018
Subsequent Event [Line Items]
Common stock issued pursuant to the distribution reinvestment plan												$ 0
Stock redeemed during period (in shares)												2,791,262			790,941
Value of shares redeemed												$ 5,292
Dividends per share declared (in usd per share)					$ 0.0015068493					$ 0.14	$ 0.14	$ 0.42		$ 0.42
Subsequent Event
Subsequent Event [Line Items]
Dividends per share declared (in usd per share)						$ 0.00150684932
Subsequent Event | Distribution Reinvestment Plan
Subsequent Event [Line Items]
Stock Issued During Period, Shares, Dividend Reinvestment Plan	7,372,224												4,818,911
Common stock issued pursuant to the distribution reinvestment plan	$ 70,200
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan													$ 45,600
Subsequent Event | Follow-on Offering [Member]
Subsequent Event [Line Items]
Stock Issued During Period, Shares, Dividend Reinvestment Plan													299,515
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan													$ 2,800
Share Redemption Program
Subsequent Event [Line Items]
Stock redeemed during period (in shares)										585,525	146,083	1,306,834		413,842	623,499	167,442		790,941
Value of shares redeemed												$ 12,200			$ 5,700	$ 1,600		$ 7,400
Stock Redeemed or Called During Period, Weighted Average Price per Share										$ 9.65	$ 9.06	$ 9.36		$ 9.18	$ 9.21	$ 9.72		$ 9.32
Share Redemption Program | Subsequent Event
Subsequent Event [Line Items]
Stock redeemed during period (in shares)								217,088
Value of shares redeemed				$ 6,700				$ 2,000
Stock Redeemed or Called During Period, Weighted Average Price per Share				$ 9.62				$ 9.09
Griffin Capital Essential Asset REIT, Inc. [Member]
Subsequent Event [Line Items]
Common stock issued pursuant to the distribution reinvestment plan												$ 33,667		$ 37,438	$ 49,541	$ 52,174	$ 52,557
Dividends per share declared (in usd per share)					$ 0.001901096					$ 0.17	$ 0.17	$ 0.51		$ 0.51
Griffin Capital Essential Asset REIT, Inc. [Member] | Subsequent Event
Subsequent Event [Line Items]
Stock Issued During Period, Shares, Dividend Reinvestment Plan													19,135,619
Estimated net asset value per share (in usd per share)																			$ 10.05
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan													$ 196,500
Dividends per share declared (in usd per share)													$ 0.001901096
Griffin Capital Essential Asset REIT, Inc. [Member] | Subsequent Event | Distribution Reinvestment Plan
Subsequent Event [Line Items]
Number of shares issued (in shares)									22,100,900
Common stock issued pursuant to the distribution reinvestment plan									$ 226,300
Griffin Capital Essential Asset REIT, Inc. [Member] | Share Redemption Program
Subsequent Event [Line Items]
Stock redeemed during period (in shares)										1,311,582	2,936,150	8,013,521		6,155,290	9,931,245	4,164,955
Value of shares redeemed												$ 76,900			$ 98,900	$ 41,400
Weighted average price per share (in dollars per share)										$ 9.63	$ 9.97	$ 9.60		$ 9.98	$ 9.96	$ 9.95
Griffin Capital Essential Asset REIT, Inc. [Member] | Share Redemption Program | Subsequent Event
Subsequent Event [Line Items]
Stock redeemed during period (in shares)			681,757
Value of shares redeemed			$ 6,700
Weighted average price per share (in dollars per share)			$ 9.76
Griffin Capital Essential Asset REIT, Inc. [Member] | Quad Graphics Property | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of property		$ 10,700
Proceeds from termination fees, net closing costs and credits		3,900
Carrying value of property sold		$ 9,900
Advisor and Property Manager Fees - Performance Distribution [Member]
Subsequent Event [Line Items]
Performance Distribution, Percentage Of Total Return												12.50%			12.50%
Related Party Transaction, Amounts of Transaction							$ 1,200
Advisor and Property Manager Fees - Performance Distribution [Member] | Subsequent Event
Subsequent Event [Line Items]
Related Party Transaction, Amounts of Transaction							1,200
Limited Partnership Units [Member] | Advisor and Property Manager Fees - Performance Distribution [Member]
Subsequent Event [Line Items]
Related Party Transaction, Amounts of Transaction							1,200
Limited Partnership Units [Member] | Advisor and Property Manager Fees - Performance Distribution [Member] | Subsequent Event
Subsequent Event [Line Items]
Related Party Transaction, Amounts of Transaction							$ 1,200

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 126,970
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	122,482
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	1,055,471
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	122,482
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	1,056,384
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	1,178,866	$ 1,133,055	$ 516,965	$ 0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	83,905	39,955	12,061	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	913
Owens Corning Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	3,300
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	575
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	5,167
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	575
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	5,167
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	5,742
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	485
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Wyndham Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,696
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	76,532
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,696
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	76,532
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	82,228
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,601
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Westgate II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	34,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,732
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	55,101
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,732
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	55,101
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	58,833
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,488
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Administrative Offices of Pennsylvania Courts [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	6,070
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,207
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	8,936
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,207
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	8,936
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	10,143
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	994
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
American Express Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	54,900
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	113,670
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	113,670
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	119,420
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	17,706
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
MGM Corporate Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	18,180
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,260
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	28,705
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,260
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	29,110
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	33,370
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,387
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	405
American Showa [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	10,320
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,453
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	15,747
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,453
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	15,747
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	17,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,475
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Huntington Ingalls [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,415
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	29,836
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,415
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	29,854
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	35,269
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,778
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	18
Exel [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,988
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	13,958
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,988
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	13,958
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	15,946
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,461
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Morpho Detection [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,350
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	9,482
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,350
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	9,482
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	11,832
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,132
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
FedEx Freight [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,774
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	25,913
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,774
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	25,913
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	28,687
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,331
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Aetna Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,853
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	20,481
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,853
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	20,481
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	22,334
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,243
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Bank of American I [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,491
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	23,514
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,491
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	23,652
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	29,143
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,724
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	138
Bank of American II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	9,206
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	20,204
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	9,206
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	20,204
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	29,410
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,674
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Atlas Copco Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,480
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	16,490
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,480
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	16,490
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	17,970
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,626
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Toshiba Tec Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,130
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	36,821
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,130
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	36,821
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	40,951
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,691
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Netgear [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	20,726
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	25,887
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	20,726
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	25,930
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	46,656
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,148
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	43
Nike [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,988
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	42,397
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,988
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	42,421
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	48,409
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	4,603
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	24
Zebra Technologies [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,238
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	56,526
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,238
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	56,526
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	61,764
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,843
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
WABCO Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,302
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	12,598
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,302
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	12,598
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	13,900
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	682
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
IGT [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,325
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	64,441
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,325
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	64,481
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	70,806
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,695
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	40
3M Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,320
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	62,247
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,320
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	62,247
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	67,567
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,475
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Amazon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,331
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	85,770
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,331
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	85,770
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	91,101
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,903
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Zoetis Headquarters Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,375
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	42,265
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,375
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	42,265
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	45,640
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,749
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Southern Co. Services HQ Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,605
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	122,679
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,605
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	122,724
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	129,329
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,488
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	45
The Allstate Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,808
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	14,090
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,808
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	14,290
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	16,098
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	679
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	200
MISO Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,104
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	26,014
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,104
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	26,014
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	29,118
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	844
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost	0
Griffin Capital Essential Asset REIT, Inc. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	672,626
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	342,021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	2,405,910
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	121,397
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	342,021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	2,527,307
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	2,869,328	3,024,389	2,968,982	1,823,895
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	426,752	$ 338,552	$ 208,933	$ 102,883
Real Estate Owned, Valuation Allowance	300
Griffin Capital Essential Asset REIT, Inc. [Member] | Plainfield [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,709
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	27,335
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	2,217
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,709
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	29,552
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	33,261
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	11,477
Griffin Capital Essential Asset REIT, Inc. [Member] | Renfro [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	13,320
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	18,804
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,390
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	20,194
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	21,594
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	7,075
Griffin Capital Essential Asset REIT, Inc. [Member] | Emporia Partners [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	2,978
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	274
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	7,567
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	274
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	7,567
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	7,841
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,378
Griffin Capital Essential Asset REIT, Inc. [Member] | Quad Graphics [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	7,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,950
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	10,236
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	292
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,950
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	10,528
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	12,478
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,723
Griffin Capital Essential Asset REIT, Inc. [Member] | ATT [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	25,655
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,770
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	32,420
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	461
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,770
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	32,881
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	39,651
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	8,535
Griffin Capital Essential Asset REIT, Inc. [Member] | Westinghouse [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	21,708
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,650
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	26,745
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,650
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	26,745
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	29,395
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,193
Griffin Capital Essential Asset REIT, Inc. [Member] | Transdigm [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	4,539
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,773
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	9,030
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	408
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,773
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	9,438
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	13,211
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,350
Griffin Capital Essential Asset REIT, Inc. [Member] | Travelers [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	9,374
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,600
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	13,500
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	873
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,600
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	14,373
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	16,973
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,771
Griffin Capital Essential Asset REIT, Inc. [Member] | Zeller Plastik [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	8,880
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,674
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	13,229
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	651
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,674
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	13,880
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	16,554
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,654
Griffin Capital Essential Asset REIT, Inc. [Member] | Northrop Grumman [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	10,667
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,300
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	16,188
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	39
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,300
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	16,227
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	17,527
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,057
Griffin Capital Essential Asset REIT, Inc. [Member] | Health Net [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	13,321
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,182
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	18,072
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,182
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	18,072
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	22,254
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,520
Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Greenwood Village Co [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,146
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	22,826
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,517
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,146
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	24,343
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	27,489
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,705
Griffin Capital Essential Asset REIT, Inc. [Member] | Boeing Renton [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	9,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	102
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	9,102
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	12,102
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	4,377
Griffin Capital Essential Asset REIT, Inc. [Member] | Schlumberger Houston [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	29,689
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,800
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	47,752
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	145
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,800
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	47,897
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	50,697
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	8,090
Griffin Capital Essential Asset REIT, Inc. [Member] | United Technologies Charlotte NC [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	23,467
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	37,858
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	37,858
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	39,188
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,982
Griffin Capital Essential Asset REIT, Inc. [Member] | Avnet Chandler AZ [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	19,615
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,860
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	31,481
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,860
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	31,481
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	33,341
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,724
Griffin Capital Essential Asset REIT, Inc. [Member] | Connecticut General Life Insurance, Phoenix AZ [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	375,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	8,600
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	48,102
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	8,600
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	48,102
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	56,702
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	8,811
Griffin Capital Essential Asset REIT, Inc. [Member] | Nokia Solution And Networks, Arlington Heights, IL [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	7,697
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	21,843
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	7,697
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	21,843
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	29,540
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,362
Griffin Capital Essential Asset REIT, Inc. [Member] | Verizon Property, Warren NJ [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	25,837
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,300
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	36,768
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	2,010
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,300
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	38,778
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	44,078
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	9,858
Griffin Capital Essential Asset REIT, Inc. [Member] | Fox Head Property, Irvine CA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,672
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	23,230
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,672
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	23,230
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	26,902
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,442
Griffin Capital Essential Asset REIT, Inc. [Member] | Coca-Cola Refreshments, Atlanta GA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	50,227
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,946
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	52,173
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	57,173
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	11,845
Griffin Capital Essential Asset REIT, Inc. [Member] | General Electric, Atlanta GA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,050
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	51,396
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	153
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,050
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	51,549
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	56,599
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	7,398
Griffin Capital Essential Asset REIT, Inc. [Member] | Atlanta Wildwood, Atlanta GA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,189
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	23,414
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,612
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,189
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	25,026
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	29,215
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,523
Griffin Capital Essential Asset REIT, Inc. [Member] | Community Insurance, Mason OH [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,177
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	22,323
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,177
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	22,323
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	23,500
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,883
Griffin Capital Essential Asset REIT, Inc. [Member] | Anthem, Mason OH [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	850
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	8,892
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	850
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	8,892
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	9,742
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,071
Griffin Capital Essential Asset REIT, Inc. [Member] | JP Morgan Chase, Westerville OH [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,500
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	39,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	212
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,500
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	39,212
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	44,712
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,531
Griffin Capital Essential Asset REIT, Inc. [Member] | IBM, Dublin OH [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	32,769
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	391
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	33,160
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	37,910
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	8,037
Griffin Capital Essential Asset REIT, Inc. [Member] | Aetna, Arlington TX [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	12,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	185
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	12,515
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	15,515
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,245
Griffin Capital Essential Asset REIT, Inc. [Member] | CHRISTUS Health, Irving TX [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,950
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	46,922
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	332
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,950
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	47,254
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	49,204
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	9,145
Griffin Capital Essential Asset REIT, Inc. [Member] | Roush Industries, Allen Park MI [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	875
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	11,375
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	534
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	875
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	11,909
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	12,784
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,979
Griffin Capital Essential Asset REIT, Inc. [Member] | Wells Fargo, Milwaukee WI [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,100
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	26,348
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	6,217
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,100
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	32,565
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	35,665
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	12,475
Griffin Capital Essential Asset REIT, Inc. [Member] | Shire Pharmaceuticals, Wayne PA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,925
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	18,935
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	715
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,925
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	19,650
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	22,575
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	6,865
Griffin Capital Essential Asset REIT, Inc. [Member] | United HealthCare, St. Louis MO [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,920
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	23,510
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	283
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,920
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	23,793
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	26,713
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,983
Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Northpointe Corporate Center II, Lynwood WA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,109
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	6,066
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	4,576
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,109
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	10,642
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	11,751
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,003
Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Northpointe Corporate Center I, Lynwood WA [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,292
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	16,930
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,571
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,292
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	18,501
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	20,793
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,957
Griffin Capital Essential Asset REIT, Inc. [Member] | Farmers, Kansas City KS [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	17,106
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	51
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	17,157
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	19,907
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,511
Griffin Capital Essential Asset REIT, Inc. [Member] | Caterpillar Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	46,511
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	46,511
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	52,511
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	10,717
Griffin Capital Essential Asset REIT, Inc. [Member] | DigitalGlobe Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	8,600
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	83,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	8,600
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	83,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	92,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	12,692
Griffin Capital Essential Asset REIT, Inc. [Member] | Waste Management Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	16,515
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	10
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	16,525
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	16,525
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,057
Griffin Capital Essential Asset REIT, Inc. [Member] | BT Infonet Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	9,800
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	41,483
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	9,800
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	41,483
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	51,283
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	7,082
Griffin Capital Essential Asset REIT, Inc. [Member] | Wyndham Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	91,153
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	91,153
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	97,353
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	10,609
Griffin Capital Essential Asset REIT, Inc. [Member] | Ace Hardware Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,900
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	33,945
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,900
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	33,945
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	40,845
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	4,795
Griffin Capital Essential Asset REIT, Inc. [Member] | Equifax Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,850
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	12,709
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	78
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,850
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	12,787
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	14,637
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,504
Griffin Capital Essential Asset REIT, Inc. [Member] | American Express Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	15,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	45,893
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	15,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	45,893
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	60,893
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	11,792
Griffin Capital Essential Asset REIT, Inc. [Member] | SoftBank Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	22,789
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	68,950
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	3,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	22,789
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	72,350
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	95,139
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	17,454
Griffin Capital Essential Asset REIT, Inc. [Member] | Vanguard Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,230
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	31,062
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,230
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	31,062
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	33,292
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	4,570
Griffin Capital Essential Asset REIT, Inc. [Member] | Restoration Hardware, California [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	15,463
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	74,213
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	15,463
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	74,213
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	89,676
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	8,135
Griffin Capital Essential Asset REIT, Inc. [Member] | Parallon Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	16,772
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	16,772
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	17,772
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,442
Griffin Capital Essential Asset REIT, Inc. [Member] | TW Telecom [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	19,169
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	10,554
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	35,817
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,240
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	10,554
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	37,057
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	47,611
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,721
Griffin Capital Essential Asset REIT, Inc. [Member] | Equifax II Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	12,755
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	70
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	12,825
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	15,025
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,015
Griffin Capital Essential Asset REIT, Inc. [Member] | Mason 1 [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,777
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	18,489
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,777
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	18,489
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	23,266
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	1,457
Griffin Capital Essential Asset REIT, Inc. [Member] | Wells Fargo [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,150
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	40,806
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	46
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,150
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	40,852
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	43,002
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	4,907
Griffin Capital Essential Asset REIT, Inc. [Member] | GE Aviation Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	61,681
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,400
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	61,681
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	66,081
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	9,046
Griffin Capital Essential Asset REIT, Inc. [Member] | Westgate III Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,209
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	75,937
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,209
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	75,937
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	79,146
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	7,727
Griffin Capital Essential Asset REIT, Inc. [Member] | Lisle [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,788
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	16,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	33
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,788
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	16,233
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	19,021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,860
Griffin Capital Essential Asset REIT, Inc. [Member] | Bloomingdale [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	588
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	2,986
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	588
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	2,986
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	3,574
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	794
Griffin Capital Essential Asset REIT, Inc. [Member] | Columbia [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,989
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	46,875
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	171
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,989
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	47,046
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	54,035
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,433
Griffin Capital Essential Asset REIT, Inc. [Member] | Denver Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	9,948
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	23,888
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	3,670
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	9,948
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	27,558
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	37,506
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,806
Griffin Capital Essential Asset REIT, Inc. [Member] | Columbus Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,943
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	22,651
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	133
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,943
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	22,784
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	25,727
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,802
Griffin Capital Essential Asset REIT, Inc. [Member] | Miramar Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,488
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	19,979
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	591
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,488
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	20,570
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	25,058
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,994
Griffin Capital Essential Asset REIT, Inc. [Member] | Irving Carpenter Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,842
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	22,052
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	3,463
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,842
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	25,515
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	27,357
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,142
Griffin Capital Essential Asset REIT, Inc. [Member] | Frisco Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	8,239
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	51,395
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	3,917
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	8,239
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	55,312
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	63,551
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	5,720
Griffin Capital Essential Asset REIT, Inc. [Member] | Houston Westway Two [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	3,961
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	78,668
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	3,961
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	78,668
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	82,629
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	10,791
Griffin Capital Essential Asset REIT, Inc. [Member] | Houston Westway One [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	6,540
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	30,703
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	6,540
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	30,703
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	37,243
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	4,622
Griffin Capital Essential Asset REIT, Inc. [Member] | Atlanta Perimeter Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	8,607
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	96,718
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	447
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	8,607
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	97,165
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	105,772
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	14,370
Griffin Capital Essential Asset REIT, Inc. [Member] | Herndon Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	9,666
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	74,098
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	9,666
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	74,098
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	83,764
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	9,679
Griffin Capital Essential Asset REIT, Inc. [Member] | Deerfield Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,339
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	37,298
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	1,032
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,339
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	38,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	42,669
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	8,467
Griffin Capital Essential Asset REIT, Inc. [Member] | Griffin Capital (Highway 94) Investors, DST [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	17,352
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,637
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	25,280
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,637
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	25,280
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	30,917
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,636
Griffin Capital Essential Asset REIT, Inc. [Member] | DynCorp [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,952
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	15,540
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,952
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	15,540
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	17,492
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,040
Griffin Capital Essential Asset REIT, Inc. [Member] | Mercedes-Benz [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	26,376
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	26,376
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	28,706
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,369
Griffin Capital Essential Asset REIT, Inc. [Member] | Samsonite [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	22,961
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	5,040
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	42,490
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	5,040
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	42,490
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	47,530
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	3,140
Griffin Capital Essential Asset REIT, Inc. [Member] | Lynwood III and IV, Washington [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	2,865
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	2,865
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	2,865
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	0
Griffin Capital Essential Asset REIT, Inc. [Member] | HealthSpring [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	21,694
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	8,126
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	31,447
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	8,126
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	31,447
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	39,573
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	2,503
Griffin Capital Essential Asset REIT, Inc. [Member] | Fort Mill Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	4,612
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	86,352
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	4,612
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	86,352
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	90,964
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	222
Griffin Capital Essential Asset REIT, Inc. [Member] | Fort Mill II Property [Member] | Operating Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land	1,275
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements	41,507
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Building and Improvements	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount	1,275
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount	41,507
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross	42,782
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation	$ 105
Minimum | Owens Corning Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Wyndham Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Westgate II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Administrative Offices of Pennsylvania Courts [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | American Express Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | MGM Corporate Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | American Showa [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Huntington Ingalls [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Exel [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Morpho Detection [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | FedEx Freight [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Aetna Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Bank of American I [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Bank of American II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Atlas Copco Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Toshiba Tec Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Netgear [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Nike [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Zebra Technologies [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | WABCO Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | IGT [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | 3M Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Amazon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Zoetis Headquarters Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Southern Co. Services HQ Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | The Allstate Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | MISO Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Plainfield [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Renfro [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Emporia Partners [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Quad Graphics [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | ATT [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Westinghouse [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Transdigm [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Travelers [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Zeller Plastik [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Northrop Grumman [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Health Net [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Greenwood Village Co [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Boeing Renton [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Schlumberger Houston [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | United Technologies Charlotte NC [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Avnet Chandler AZ [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Connecticut General Life Insurance, Phoenix AZ [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Nokia Solution And Networks, Arlington Heights, IL [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Verizon Property, Warren NJ [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Fox Head Property, Irvine CA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Coca-Cola Refreshments, Atlanta GA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | General Electric, Atlanta GA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Atlanta Wildwood, Atlanta GA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Community Insurance, Mason OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Anthem, Mason OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | JP Morgan Chase, Westerville OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | IBM, Dublin OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Aetna, Arlington TX [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | CHRISTUS Health, Irving TX [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Roush Industries, Allen Park MI [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Wells Fargo, Milwaukee WI [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Shire Pharmaceuticals, Wayne PA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | United HealthCare, St. Louis MO [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Northpointe Corporate Center II, Lynwood WA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Northpointe Corporate Center I, Lynwood WA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Farmers, Kansas City KS [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Caterpillar Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | DigitalGlobe Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Waste Management Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | BT Infonet Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Wyndham Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Ace Hardware Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Equifax Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | American Express Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | SoftBank Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Vanguard Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Restoration Hardware, California [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Parallon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | TW Telecom [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Equifax II Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Mason 1 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Wells Fargo [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | GE Aviation Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Westgate III Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Lisle [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Bloomingdale [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Columbia [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Denver Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Columbus Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Miramar Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Irving Carpenter Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Frisco Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Houston Westway Two [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Houston Westway One [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Atlanta Perimeter Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Herndon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Deerfield Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Griffin Capital (Highway 94) Investors, DST [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | DynCorp [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Mercedes-Benz [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Samsonite [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Fort Mill Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Minimum | Griffin Capital Essential Asset REIT, Inc. [Member] | Fort Mill II Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	5 years
Maximum | Owens Corning Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Wyndham Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Westgate II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Administrative Offices of Pennsylvania Courts [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | American Express Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | MGM Corporate Center [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | American Showa [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Huntington Ingalls [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Exel [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Morpho Detection [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | FedEx Freight [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Aetna Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Bank of American I [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Bank of American II [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Atlas Copco Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Toshiba Tec Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Netgear [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Nike [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Zebra Technologies [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | WABCO Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | IGT [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | 3M Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Amazon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Zoetis Headquarters Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Southern Co. Services HQ Properties [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | The Allstate Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | MISO Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Plainfield [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Renfro [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Emporia Partners [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Quad Graphics [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | ATT [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Westinghouse [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Transdigm [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Travelers [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Zeller Plastik [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Northrop Grumman [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Health Net [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Greenwood Village Co [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Boeing Renton [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Schlumberger Houston [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | United Technologies Charlotte NC [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Avnet Chandler AZ [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Connecticut General Life Insurance, Phoenix AZ [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Nokia Solution And Networks, Arlington Heights, IL [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Verizon Property, Warren NJ [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Fox Head Property, Irvine CA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Coca-Cola Refreshments, Atlanta GA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | General Electric, Atlanta GA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Atlanta Wildwood, Atlanta GA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Community Insurance, Mason OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Anthem, Mason OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | JP Morgan Chase, Westerville OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | IBM, Dublin OH [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Aetna, Arlington TX [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | CHRISTUS Health, Irving TX [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Roush Industries, Allen Park MI [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Wells Fargo, Milwaukee WI [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Shire Pharmaceuticals, Wayne PA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | United HealthCare, St. Louis MO [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Northpointe Corporate Center II, Lynwood WA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Comcast Northpointe Corporate Center I, Lynwood WA [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Farmers, Kansas City KS [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Caterpillar Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | DigitalGlobe Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Waste Management Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | BT Infonet Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Wyndham Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Ace Hardware Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Equifax Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | American Express Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | SoftBank Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Vanguard Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Restoration Hardware, California [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Parallon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | TW Telecom [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Equifax II Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Mason 1 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Wells Fargo [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | GE Aviation Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Westgate III Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Lisle [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Bloomingdale [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Columbia [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Denver Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Columbus Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Miramar Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Irving Carpenter Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Frisco Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Houston Westway Two [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Houston Westway One [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Atlanta Perimeter Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Herndon Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Deerfield Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Griffin Capital (Highway 94) Investors, DST [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | DynCorp [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Mercedes-Benz [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Samsonite [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Fort Mill Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years
Maximum | Griffin Capital Essential Asset REIT, Inc. [Member] | Fort Mill II Property [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation	40 years

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation Schedule III - Real Estate and Accumulated Depreciation - Rollforward of Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2018
Real estate facilities
Balance at beginning of year	$ 1,133,055	$ 516,965	$ 0
Acquisitions	45,016	615,972	516,965
Improvements	576	38	0
Construction-in-progress	219	80	0
Balance at end of year	1,178,866	1,133,055	516,965
Accumulated depreciation
Balance at beginning of year	39,955	12,061	0
Depreciation and amortization expense	43,950	27,894	12,061
Balance at end of year	83,905	39,955	12,061
Total real estate, net	1,094,961	1,093,100	504,904	$ 1,064,769
Griffin Capital Essential Asset REIT, Inc. [Member]
Real estate facilities
Balance at beginning of year	3,024,389	2,968,982	1,823,895
Acquisitions	133,747	42,438	1,087,153
Improvements	12,479	16,792	7,382
Construction-in-progress	1,752	575	45,067
Other adjustments	(2,785)	(4,398)	0
Real estate assets held and used	0	0	70,907
Write down of tenant origination and absorption costs	(2,352)	0	0
Sale of real estate assets	(297,902)	0	(65,422)
Balance at end of year	2,869,328	3,024,389	2,968,982
Accumulated depreciation
Balance at beginning of year	338,552	208,933	102,883
Depreciation and amortization expense	116,583	130,849	112,748
Depreciation expense (held and used adjustment)	0	0	4,621
Less: Non-real estate assets depreciation expense	(1,554)	(1,230)	(328)
Less: Sale of real estate assets depreciation expense	(26,829)	0	(10,991)
Balance at end of year	426,752	338,552	208,933
Total real estate, net	$ 2,439,795	$ 2,685,837	$ 2,760,049	$ 2,564,832