Name:	bkng_EmploymentAgreementsCashSeverancePaymentsMaximum
Namespace Prefix:	bkng_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

EmploymentContracts [Abstract]

No definition available.

Name:	bkng_EmploymentcontractsAbstract
Namespace Prefix:	bkng_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The maximum extension period, in years, for health and insurance benefits after termination for certain agreements.

No definition available.

Name:	bkng_ExtensionPeriodForHealthAndInsuranceBenefitsAfterTerminationHighEndOfRange
Namespace Prefix:	bkng_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

No definition available.

Name:	bkng_LossContingencyNumberOfLawsuits
Namespace Prefix:	bkng_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Loss Contingency, Reversal of Liability based on rulings

No definition available.

Name:	bkng_LossContingencyReversalofLiabilitybasedonrulings
Namespace Prefix:	bkng_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

No definition available.

Name:	bkng_LossContingencyTaxInterestandPenaltiesAssessed
Namespace Prefix:	bkng_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Payment required to appeal a litigation matter

No definition available.

Name:	bkng_Paymentrequiredtoappealalitigationmatter
Namespace Prefix:	bkng_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Pricing Parity Working Group

No definition available.

Name:	bkng_PricingParityWorkingGroup
Namespace Prefix:	bkng_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

No definition available.

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

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.

No definition available.

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

Amount of loss contingency liability.

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=82911808&loc=d3e14326-108349

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

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=bkng_LitigationRelatedtoTravelTransactionTaxesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=bkng_FrenchTaxAuditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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