Group statement of changes in equity (Parenthetical) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Statement of changes in equity [abstract]
Sharebased Payment Transactions Reclassification Of Cash Settled Awards	$ (3)

Sharebased payment transactions reclassification of cash settled awards.

No definition available.

Name:	ihg_SharebasedPaymentTransactionsReclassificationOfCashSettledAwards
Namespace Prefix:	ihg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration