This element represents the number of municipalities or counties which have initiated audit proceedings.

No definition available.

Name:	pcln_LossContingencyAuditProceedingsNumberOfMunicipalitiesAndCounties
Namespace Prefix:	pcln_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the number of states which have initiated audit proceedings.

+ References

No definition available.

+ Details

Name:	pcln_LossContingencyAuditProceedingsNumberOfStates
Namespace Prefix:	pcln_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	pcln_LossContingencyNumberOfLawsuits
Namespace Prefix:	pcln_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Loss Contingency, Refund amount based on rulings

+ References

No definition available.

+ Details

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Namespace Prefix:	pcln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loss Contingency, Reversal of Liability based on rulings

+ References

No definition available.

+ Details

Name:	pcln_LossContingencyReversalofLiabilitybasedonrulings
Namespace Prefix:	pcln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	pcln_LossContingencyTaxInterestandPenaltiesAssessed
Namespace Prefix:	pcln_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

PaymentsOfTaxAndInterestForLossContingencyRelatedToHotelOccupancyAndOtherTaxes

+ References

No definition available.

+ Details

Name:	pcln_PaymentsOfTaxAndInterestForLossContingencyRelatedToHotelOccupancyAndOtherTaxes
Namespace Prefix:	pcln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

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)(3)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Name:	us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow
Namespace Prefix:	us-gaap_
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 35

-Paragraph 1

-Subparagraph b

-URI http://asc.fasb.org/extlink&oid=6911338&loc=d3e6819-128478

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	pcln_LitigationRelatedtoTravelTransactionTaxesByGeographicAreaAxis=stpr_CA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pcln_LitigationRelatedtoTravelTransactionTaxesByGeographicAreaAxis=pcln_CityOfSanFranciscoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pcln_LitigationRelatedtoTravelTransactionTaxesByGeographicAreaAxis=stpr_HI
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pcln_LitigationRelatedtoTravelTransactionTaxesByGeographicAreaAxis=stpr_DC
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember
Namespace Prefix:
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COMMITMENTS AND CONTINGENCIES (Details)	1 Months Ended		3 Months Ended			6 Months Ended	12 Months Ended
COMMITMENTS AND CONTINGENCIES (Details)	Jan. 31, 2013 USD ($)	Jul. 31, 2009 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2013 USD ($)	Sep. 30, 2012 USD ($)	Jun. 30, 2015 USD ($) Cases GovernmentalUnit	Dec. 31, 2014 USD ($)	Dec. 31, 2012 USD ($)
Litigation related to travel transaction taxes [Member]
Travel Transaction Taxes
Approximate number of lawsuits brought by or against states, cities and counties over issues involving the payment of travel transaction taxes (in cases) \| Cases						40
Accrual for the potential resolution of issues related to travel transaction taxes (in dollars)						$ 33,000,000	$ 52,000,000
Minimum [Member] \| Litigation related to travel transaction taxes [Member]
Travel Transaction Taxes
Minimum number of municipalities and counties which have initiated audit proceedings (in governmental units) \| GovernmentalUnit						79
Minimum number of states which have initiated audit proceedings (in governmental units) \| GovernmentalUnit						11
State of California [Member] \| Minimum [Member] \| Litigation related to travel transaction taxes [Member]
Travel Transaction Taxes
Minimum number of municipalities and counties which have initiated audit proceedings (in governmental units) \| GovernmentalUnit						40
City and County of San Francisco [Member] \| Litigation related to travel transaction taxes [Member]
Travel Transaction Taxes
Assessed taxes including interest and penalties (in dollars)	$ 2,700,000	$ 3,400,000
Hawaii [Member] \| Litigation related to travel transaction taxes [Member]
Travel Transaction Taxes
Assessed taxes including interest and penalties (in dollars)				$ 18,700,000				$ 16,500,000
Payments of tax and interest for loss contingency related to travel transaction taxes (in dollars)						$ 600,000	2,200,000
Loss contingency, refund amount based on rulings						20,000,000
Loss contingency, reversal of liability based on rulings			$ 16,400,000
District of Columbia [Member] \| Litigation related to travel transaction taxes [Member]
Travel Transaction Taxes
Assessed taxes including interest and penalties (in dollars)				$ 5,600,000	$ 4,800,000
Series of individually immaterial business acquisitions [Member]
Travel Transaction Taxes
Contingent consideration liability						20,000,000	$ 11,000,000
Contingent consideration arrangements, range of outcomes, minimum value						0
Contingent consideration arrangements, range of outcomes, maximum value						$ 161,000,000