Acquisition of land use rights

No definition available.

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- Definition

This element represents the number of lawsuits in which the reporting entity was involved.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

Represents the tax assessment issued by the tax authority including interest and penalties.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Payment required to appeal a litigation matter

+ References

No definition available.

+ Details

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- Definition

Pricing Parity Working Group

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Number of units of account associated with a transaction

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

For contingent consideration arrangements and indemnification assets recognized in connection with a business combination, this element represents an estimate of the low-end of the potential range (undiscounted) of the consideration which may be paid.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of liability recognized arising from contingent consideration in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
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- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
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Data Type:	xbrli:durationItemType
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- 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

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Data Type:	xbrli:stringItemType
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- Definition

Amount of loss contingency liability.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
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Period Type:	duration

- Definition

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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COMMITMENTS AND CONTINGENCIES (Details) € in Millions		3 Months Ended	6 Months Ended
COMMITMENTS AND CONTINGENCIES (Details) € in Millions	Jul. 24, 2017 USD ($)	Sep. 30, 2016 EUR (€)	Jun. 30, 2017 USD ($) Cases country	Jun. 30, 2017 EUR (€) country	Jun. 30, 2016 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($)
Commitments and Contingencies
Pricing Parity Working Group \| country			10	10
Payments to Acquire Property, Plant, and Equipment \| $			$ 147,269,000		$ 113,699,000
Litigation related to travel transaction taxes [Member]
Commitments and Contingencies
Approximate number of lawsuits brought by or against states, cities and counties over issues involving the payment of travel transaction taxes (in cases) \| Cases			20
Accrual for the potential resolution of issues related to travel transaction taxes (in dollars) \| $			$ 26,000,000				$ 27,000,000
French Tax Audit [Member]
Commitments and Contingencies
Assessed taxes including interest and penalties \| €				€ 356
Series of individually immaterial business acquisitions [Member]
Commitments and Contingencies
Contingent consideration arrangements, range of outcomes, minimum value \| $			0
Contingent consideration arrangements, range of outcomes, maximum value \| $			90,000,000
Booking.com [Member] \| Headquarters [Member]
Commitments and Contingencies
Contractual Obligation for Building Construction \| €		€ 270
Units of account		2
Payments to Acquire Productive Assets \| €		€ 48
Acquisition of land use rights \| €		43
Payments to Acquire Property, Plant, and Equipment \| €		5
Ground Lease [Member] \| Booking.com [Member] \| Headquarters [Member]
Commitments and Contingencies
Contractual Obligation for Building Construction \| €		€ 60
Lessee, Operating Lease, Term of Contract		49 years
Fair Value, Inputs, Level 3 [Member] \| Series of individually immaterial business acquisitions [Member]
Commitments and Contingencies
Contingent consideration liability \| $			9,000,000				$ 9,000,000
Subsequent Event [Member] \| Momondo Group [Member]
Commitments and Contingencies
Payments to Acquire Businesses, Gross \| $	$ 550,000,000
Scenario, Forecast [Member] \| Booking.com [Member] \| Headquarters [Member]
Commitments and Contingencies
Contractual Obligation for Building Construction \| €						€ 34
HAWAII \| Litigation related to travel transaction taxes [Member]
Commitments and Contingencies
Payment required to appeal a litigation matter \| $			$ 13,100,000