Cash Institution Covenant

No definition available.

Name:	grpn_CashInstitutionCovenant
Namespace Prefix:	grpn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit, Secured, Outstanding Stock Percentage

+ References

No definition available.

+ Details

Name:	grpn_LineofCreditSecuredOutstandingStockPercentage
Namespace Prefix:	grpn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Unrestricted Cash Covenant

+ References

No definition available.

+ Details

Name:	grpn_UnrestrictedCashCovenant
Namespace Prefix:	grpn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt 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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
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

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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	grpn_LocationAxis=us-gaap_GeographicDistributionDomesticMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	grpn_LocationAxis=us-gaap_GeographicDistributionForeignMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

FINANCING ARRANGEMENTS - Revolving Credit Facility (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2016	Apr. 04, 2016
Debt Instrument [Line Items]
Aggregate principal amount	$ 250.0
Stated interest rate				3.25%
Unrestricted cash covenant amount			$ 400.0
Amount of accounts held with lenders			$ 200.0
Outstanding amount of lines of credit	$ 18.3	$ 22.7
Minimum
Debt Instrument [Line Items]
Unused commitment fee percentage	0.25%
Maximum
Debt Instrument [Line Items]
Unused commitment fee percentage	0.40%
Letter of Credit
Debt Instrument [Line Items]
Aggregate principal amount	$ 45.0
Letter of Credit \| Base Rate \| Minimum
Debt Instrument [Line Items]
Stated interest rate	0.50%
Letter of Credit \| Base Rate \| Maximum
Debt Instrument [Line Items]
Stated interest rate	2.25%
Geographic Distribution, Domestic
Debt Instrument [Line Items]
Outstanding stock percentage	100.00%
Geographic Distribution, Foreign
Debt Instrument [Line Items]
Outstanding stock percentage	65.00%