Finance Costs - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Detailed Finance (Income) Costs Explanatory [line items]
Interest expense on borrowings	$ 66	$ 62	$ 71
Rate used for capitalisation of interest	3.00%	3.00%	3.80%
System Fund [member]
Disclosure Of Detailed Finance (Income) Costs Explanatory [line items]
Interest costs capitalised	$ 5	$ 6	$ 4
IHG Rewards club loyalty programme [member]
Disclosure Of Detailed Finance (Income) Costs Explanatory [line items]
Interest expense on borrowings	$ 14	$ 7	$ 3

The weighted average of interest and other costs that an entity incurs in connection with the borrowing of funds applicable to the borrowings of the entity that are outstanding during the period, other than borrowings made specifically for the purpose of obtaining a qualifying asset. [Refer: Weighted average [member]; Borrowings]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 23
-IssueDate 2018-01-01
-Paragraph 26
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=23&date=2018-03-01&anchor=para_26_b&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_CapitalisationRateOfBorrowingCostsEligibleForCapitalisation
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of interest costs that an entity incurs in connection with the borrowing of funds that are directly attributable to the acquisition, construction or production of a qualifying asset and which form part of the cost of that asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_InterestCostsCapitalised
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of interest expense on borrowings. [Refer: Interest expense; Borrowings]

+ References

+ Details

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

- Definition

Disclosure Of Detailed Finance (Income) Costs Explanatory [line items]

+ References

No definition available.

+ Details

Name:	ihg_DisclosureOfDetailedFinanceIncomeCostsExplanatoryLineItems
Namespace Prefix:	ihg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=ihg_SystemFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ProductsAndServicesAxis=ihg_IHGRewardsClubLoyaltyProgrammeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: