XML 103 R49.htm IDEA: XBRL DOCUMENT v3.10.0.1

Investments - Narrative (Details) - Griffin Capital Essential Asset REIT, Inc. [Member]		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 09, 2014 USD ($) ft²	Jun. 30, 2018 USD ($)	Sep. 30, 2018 USD ($) ft²	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) ft²	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
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

X

- Definition

Equity Method Investment, Area of Real Estate Property

+ References

No definition available.

+ Details

Name:	gcnl_EquityMethodInvestmentAreaofRealEstateProperty
Namespace Prefix:	gcnl_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Equity Method Investment, Equity Contributed by Members to Fund Project Costs

+ References

No definition available.

+ Details

Name:	gcnl_EquityMethodInvestmentEquityContributedbyMemberstoFundProjectCosts
Namespace Prefix:	gcnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Equity Method Investment, Operating Leases, Term of Contract

+ References

No definition available.

+ Details

Name:	gcnl_EquityMethodInvestmentLessorLeasingArrangementsOperatingLeasesTermofContract
Namespace Prefix:	gcnl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Equity Method Investment, Project Budget

+ References

No definition available.

+ Details

Name:	gcnl_EquityMethodInvestmentProjectBudget
Namespace Prefix:	gcnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Other Comprehensive Income (Loss), Unrealized Gain (Loss) for Equity Investee's Gain (Loss) on Derivatives Arising During Period, Net of Tax

+ References

No definition available.

+ Details

Name:	gcnl_OtherComprehensiveIncomeLossUnrealizedGainLossforEquityInvesteesGainLossonDerivativesArisingDuringPeriodNetofTax
Namespace Prefix:	gcnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The amount of noncurrent assets reported by an equity method investment of the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33912-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The amount of noncurrent liabilities reported by an equity method investment of the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33912-111571

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

+ Details

Name:	us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss), attributable to noncontrolling interests.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683

+ Details

Name:	us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireInterestInJointVenture
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	dei_LegalEntityAxis=gcnl_GriffinCapitalEssentialAssetREITInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gcnl_HeritageCommonXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gcnl_JointVentureAffiliateofDigitalRealtyTrustInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: