Debt Instrument, Basis Spread On Base Rate

No definition available.

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- Definition

Line Of Credit Facility, Accordion Feature, Higher Borrowing Capacity Option

+ References

No definition available.

+ Details

Name:	gnl_LineOfCreditFacilityAccordionFeatureHigherBorrowingCapacityOption
Namespace Prefix:	gnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Accordion Feature, Increase Limit

+ References

No definition available.

+ Details

Name:	gnl_LineofCreditFacilityAccordionFeatureIncreaseLimit
Namespace Prefix:	gnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

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

- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfBusinessesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow from the acquisition of a piece of land, anything permanently fixed to it, including buildings, structures on it and so forth; includes real estate intended to generate income for the owner; excludes real estate acquired for use by the owner.

+ 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 (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=gnl_SeniorUnsecuredMultiCurrencyRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_FederalFundsEffectiveSwapRateMember
Namespace Prefix:
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- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=gnl_KeyBankNationalAssociationMember
Namespace Prefix:
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Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=gnl_CreditFacilityAmendmentMember
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- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
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- Details

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Subsequent Events - (Details) € in Millions			1 Months Ended	6 Months Ended
Subsequent Events - (Details) € in Millions	Aug. 01, 2019 USD ($)	Jul. 24, 2017 USD ($)	Aug. 07, 2019 USD ($) property	Jun. 30, 2019 USD ($) property	Jun. 30, 2018 property	Jun. 30, 2019 EUR (€)	Dec. 31, 2018 USD ($)	Jul. 02, 2018 USD ($)
Subsequent Event [Line Items]
Number of properties acquired \| property				11	13
Borrowings outstanding, credit facility				$ 259,527,000			$ 363,894,000
Subsequent Event
Subsequent Event [Line Items]
Number of properties acquired \| property			6
Asset purchase price			$ 48,700,000
Credit Facility
Subsequent Event [Line Items]
Weighted-average effective interest rate				2.60%		2.60%
Credit Facility \| Federal Funds
Subsequent Event [Line Items]
Basis spread on base rate determination		0.50%
Credit Facility \| LIBOR
Subsequent Event [Line Items]
Basis spread on base rate determination		1.00%
Credit Facility \| Unsecured debt \| KeyBank National Association
Subsequent Event [Line Items]
Maximum borrowing capacity (up to)		$ 725,000,000.0		$ 906,200,000
Increase in aggregate commitments (up to)								$ 35,600,000
Total line of credit commitment								950,000,000.0
Credit Facility \| Unsecured debt \| KeyBank National Association \| Subsequent Event
Subsequent Event [Line Items]
Increase in aggregate commitments (up to)	$ 39,400,000
Credit Facility Amendment \| Subsequent Event
Subsequent Event [Line Items]
Maximum borrowing capacity (up to)	1,235,000,000
Increase in aggregate commitments (up to)	515,000,000.0
Total line of credit commitment	$ 1,750,000,000
Weighted-average effective interest rate	2.30%
Minimum \| Credit Facility \| Base Rate
Subsequent Event [Line Items]
Interest rate spread		0.60%
Minimum \| Credit Facility \| LIBOR
Subsequent Event [Line Items]
Interest rate spread		1.60%
Minimum \| Credit Facility \| Unsecured debt \| KeyBank National Association
Subsequent Event [Line Items]
Maximum borrowing capacity (up to)								722,200,000
Maximum \| Credit Facility \| Base Rate
Subsequent Event [Line Items]
Interest rate spread		1.20%
Maximum \| Credit Facility \| LIBOR
Subsequent Event [Line Items]
Interest rate spread		2.20%
Maximum \| Credit Facility \| Unsecured debt \| KeyBank National Association
Subsequent Event [Line Items]
Maximum borrowing capacity (up to)								$ 914,400,000
Revolving Credit Facility \| Credit Facility
Subsequent Event [Line Items]
Borrowings outstanding, credit facility				259,500,000
Borrowings outstanding, term loan				170,700,000
Revolving Credit Facility \| Credit Facility \| Unsecured debt \| KeyBank National Association
Subsequent Event [Line Items]
Maximum borrowing capacity (up to)				632,000,000.0
Borrowings outstanding, credit facility				259,527,000			$ 363,894,000
Revolving Credit Facility \| Credit Facility Amendment \| Subsequent Event
Subsequent Event [Line Items]
Maximum borrowing capacity (up to)	$ 835,000,000.0
Revolving Credit Facility \| Minimum \| Credit Facility Amendment \| Base Rate \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	0.45%
Revolving Credit Facility \| Minimum \| Credit Facility Amendment \| LIBOR \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	1.45%
Revolving Credit Facility \| Maximum \| Credit Facility Amendment \| Base Rate \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	1.05%
Revolving Credit Facility \| Maximum \| Credit Facility Amendment \| LIBOR \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	2.05%
Term Loan \| Credit Facility
Subsequent Event [Line Items]
Borrowings outstanding, credit facility				277,400,000
Borrowings outstanding, term loan				$ 400,000,000.0		€ 359.6
Term Loan \| Minimum \| Credit Facility Amendment \| Base Rate \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	0.40%
Term Loan \| Minimum \| Credit Facility Amendment \| LIBOR \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	1.40%
Term Loan \| Maximum \| Credit Facility Amendment \| Base Rate \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	1.00%
Term Loan \| Maximum \| Credit Facility Amendment \| LIBOR \| Subsequent Event
Subsequent Event [Line Items]
Interest rate spread	2.00%