The life expectancy after retirement used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 144
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_144&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_ActuarialAssumptionOfLifeExpectancyAfterRetirement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

The decrease (increase) in net defined benefit liability (asset) resulting from contributions to a defined benefit plan by the employer. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 141
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_141_f&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_ContributionsToPlanByEmployerNetDefinedBenefitLiabilityAsset
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfDefinedBenefitPlansLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimate of the expected contributions to be made to a defined benefit plan for the next annual reporting period. [Refer: Defined benefit plans [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 147
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_147_b&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 148
-Subparagraph d
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_148_d_iii&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_EstimateOfContributionsExpectedToBePaidToPlan
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=wpp_ActuarialAssumptionOfMortalityLifeExpectancyAtSixtyFiveForMaleMemberCurrentlyAtAgeSixtyFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=wpp_ActuarialAssumptionOfMortalityLifeExpectancyAtSixtyFiveForFemaleMemberCurrentlyAtAgeSixtyFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=wpp_CurrentMemberAgedFortyFiveMalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=wpp_CurrentMemberAgedFortyFiveFemalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Provision for post-employment benefits - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2018 GBP (£) yr	Dec. 31, 2017 GBP (£) yr	Dec. 31, 2016 GBP (£)
Disclosure of defined benefit plans [line items]
Employer contributions and benefit payments \| £	£ 44.9	£ 68.2	£ 43.7
Employer contributions and benefit payments, expected in 2019 \| £	£ 50.0
Years life expectancy after age 65 - current pensioners (at age 65) - male [member]
Disclosure of defined benefit plans [line items]
Actuarial assumption of life expectancy	22.2	22.4
Years life expectancy after age 65 - current pensioners (at age 65) - female [member]
Disclosure of defined benefit plans [line items]
Actuarial assumption of life expectancy	23.9	24.0
Years life expectancy after age 65 - future pensioners (current age 45) - male [member]
Disclosure of defined benefit plans [line items]
Actuarial assumption of life expectancy	24.0	23.8
Years life expectancy after age 65 - future pensioners (current age 45) - female [member]
Disclosure of defined benefit plans [line items]
Actuarial assumption of life expectancy	25.7	25.7