Income tax benefits associated with exercise settlement of stock based awards.

No definition available.

Name:	trip_IncomeTaxBenefitsAssociatedWithExerciseSettlementOfStockBasedAwards
Namespace Prefix:	trip_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Calculation price based on the average stock price of the last ten trading days.

+ References

No definition available.

+ Details

Name:	trip_NumberOfTradingDaysAverage
Namespace Prefix:	trip_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

End of requisite service period for share based compensation arrangement.

+ References

No definition available.

+ Details

Name:	trip_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriodDate
Namespace Prefix:	trip_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based compensation arrangement by share-based payment award target payment.

+ References

No definition available.

+ Details

Name:	trip_ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetPayment
Namespace Prefix:	trip_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for incentive compensation awarded to employees and directors or earned by them based on the terms of one or more relevant arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.15(a))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Amount of cost capitalized for award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Description of modification of award under share-based payment arrangement. Includes, but is not limited to, terms for expiration date, vesting rights and exercise price.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
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_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=trip_AccountsReceivableAndContractAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_EmployeeStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_AwardTypeAxis=trip_MarketBasedRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock Based Awards and Other Equity Instruments - Additional Information (Details)			3 Months Ended		9 Months Ended
	May 27, 2020	May 08, 2020 USD ($) TradingDay	Sep. 30, 2020 USD ($) $ / shares	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) $ / shares	Sep. 30, 2019 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Capitalized stock based compensation as internal-use software and website development costs			$ 4,000,000	$ 5,000,000	$ 11,000,000	$ 14,000,000
Number of Average Trading Days \| TradingDay		10
Total stock-based compensation expense			28,000,000	29,000,000	80,000,000	91,000,000
Income tax benefits from exercise or settlement of stock-based awards			1,000,000	$ 1,000,000	14,000,000	23,000,000
Other Long-term Liabilities
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accrued bonus			$ 1,000,000		$ 1,000,000
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Target payment		$ 7,000,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing stock price \| $ / shares			$ 19.59		$ 19.59
Total intrinsic value					$ 2,000,000	2,000,000
Total fair value of stock options vested					12,000,000	$ 11,000,000
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense			$ 6,000,000		$ 11,000,000
Stock award modification term					On May 27, 2020 and July 15, 2020, the Compensation Committee of the Board of Directors, approved modifications to the Company’s annual RSU and stock option grants, respectively, issued to its employees in the first quarter of 2020. Such modifications reduced the original grant-date vesting period from four years to two years.
Restricted Stock Units \| Maximum \| Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of stock options, grant-date vesting period	4 years
Restricted Stock Units \| Minimum \| Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of stock options, grant-date vesting period	2 years
MSUs \| Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Requisite service period for estimated grant-date fair value of stock awards					Dec. 31, 2022