Acquisition of land use rights

No definition available.

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

- Definition

Payment Of Contractual Obligation

+ References

No definition available.

+ Details

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

- Definition

Payment required to appeal a litigation matter

+ References

No definition available.

+ Details

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

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- 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

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

- Definition

Term of lessee's operating lease not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

+ Details

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

- Definition

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 05
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99385795&loc=d3e12631-108344

+ Details

Name:	us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=bkng_Booking.comMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=bkng_HeadquartersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=bkng_GroundLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	srt_StatementGeographicalAxis=bkng_ManchesterEnglandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=bkng_Rentalcars.comMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=bkng_OperatingLeaseObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES (Details) ₺ in Millions, € in Millions, £ in Millions, $ in Millions	1 Months Ended					3 Months Ended				12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Jan. 31, 2019 USD ($)	Jan. 31, 2019 EUR (€)	Dec. 31, 2015 EUR (€)	Mar. 31, 2020 USD ($)	Mar. 31, 2020 EUR (€)	Sep. 30, 2016 USD ($)	Sep. 30, 2016 EUR (€)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 TRY (₺)	Dec. 31, 2018 USD ($) ft²	Dec. 31, 2018 EUR (€) ft²	May 07, 2020 USD ($)	May 07, 2020 EUR (€)	Mar. 31, 2020 EUR (€)	Mar. 31, 2020 GBP (£)
Booking.com \| Headquarters
Commitments and Contingencies
Contractual obligation						$ 112										€ 102
Acquisition of land use rights								$ 48	€ 43
Payment Of Contractual Obligation						193	€ 168
Booking.com \| Headquarters \| Ground Lease
Commitments and Contingencies
Contractual obligation						78										€ 71
French Tax Audit
Commitments and Contingencies
Assessed taxes including interest and penalties	$ 77	€ 70			€ 356
Payment required to appeal a litigation matter			$ 403	€ 356
Assessment, transfer taxes [Member]
Commitments and Contingencies
Assessed taxes including interest and penalties	43	39
Taxes Owed For Prior Periods
Commitments and Contingencies
Loss contingency accrual	67					75				$ 67
Estimated reasonably possible loss in excess of amount accrued						25
Italian Tax Audit
Commitments and Contingencies
Assessed taxes including interest and penalties	64	58										$ 52	€ 48
Payment required to appeal a litigation matter	$ 11	€ 10
Turkish Tax Audit
Commitments and Contingencies
Assessed taxes including interest and penalties										$ 83	₺ 544
Pension-related litigation [Member]
Commitments and Contingencies
Estimated reasonably possible loss in excess of amount accrued						$ 200
Manchester, England \| Rentalcars.com \| Headquarters
Commitments and Contingencies
Area of real estate property \| ft²												222,000	222,000
Lease term of operating leases which have not commenced at period end						13 years										13 years	13 years
Manchester, England \| Rentalcars.com \| Headquarters \| Operating Lease Obligations
Commitments and Contingencies
Contractual obligation						$ 80											£ 65
Subsequent Event \| Booking.com \| Headquarters
Commitments and Contingencies
Contractual obligation														$ 102	€ 93