Share-based payments - Summary of Information about Awards Granted (Detail)	12 Months Ended
Dec. 31, 2021 yr £ / shares	Dec. 31, 2020 yr £ / shares	Dec. 31, 2019 yr £ / shares
Annual Performance Plan [member]
Information regarding option pricing models and assumptions used for grants during the year [line items]
Weighted average share price (pence) \| £ / shares	£ 50.09	£ 37.71	£ 45.97
Term (years) \| yr	1.5	3.0	3.0
Long Term Incentive Plan [member]
Information regarding option pricing models and assumptions used for grants during the year [line items]
Weighted average share price (pence) \| £ / shares	£ 49.80	£ 34.50	£ 48.50
Expected dividend yield	1.11%	1.48%	2.16%
Risk-free interest rate	0.09%	0.02%	0.72%
Volatility	43.00%	33.00%	19.00%
Term (years) \| yr	3.0	3.0	3.0

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 47
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_47_a_i&doctype=Standard
-URIDate 2021-03-24

+ Details

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

- Definition

The option life of share options granted.

+ References

+ Details

Name:	ifrs-full_DescriptionOfOptionLifeShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

+ References

+ Details

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

- Definition

The percentage of an expected dividend used to calculate the fair value of share options granted.

+ References

+ Details

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

- Definition

The weighted average share price used as input to the option pricing model to calculate the fair value of share options granted. [Refer: Option pricing model [member]; Weighted average [member]]

+ References

+ Details

Name:	ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

fair value of share award using monte carlo pricing model and weighted average assumptions.

+ References

No definition available.

+ Details

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

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=ihg_AnnualPerformancePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=ihg_LongtermIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: