Provisions and other current liabilities - Accruals for deductions from revenue (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
January 1	$ 264	$ 217	$ 212
Additions	878	677	540
Impact of business combination	86	0	0
Payments/utilizations	(829)	(619)	(537)
Changes in offset against gross trade receivables	(3)	(5)	(2)
Currency translation effects	(10)	(6)	4
December 31	$ 386	$ 264	$ 217

Current Deductions From Revenue Provision

No definition available.

Name:	alc_CurrentDeductionsFromRevenueProvision
Namespace Prefix:	alc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Current Deductions From Revenue Provision, Decrease For Payments And Utilizations

No definition available.

Name:	alc_CurrentDeductionsFromRevenueProvisionDecreaseForPaymentsAndUtilizations
Namespace Prefix:	alc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Current Deductions From Revenue Provision, Increase (Decrease) For Changes In Offset Against Gross Trade Receivables

No definition available.

Name:	alc_CurrentDeductionsFromRevenueProvisionIncreaseDecreaseForChangesInOffsetAgainstGrossTradeReceivables
Namespace Prefix:	alc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Current Deductions From Revenue Provision, Increase (Decrease) For Foreign Currency Translation

No definition available.

Name:	alc_CurrentDeductionsFromRevenueProvisionIncreaseDecreaseForForeignCurrencyTranslation
Namespace Prefix:	alc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Current Deductions From Revenue Provision, Increase For Additions

No definition available.

Name:	alc_CurrentDeductionsFromRevenueProvisionIncreaseForAdditions
Namespace Prefix:	alc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Current Deductions From Revenue Provision, Increase For Additions From Business Combinations

No definition available.

Name:	alc_CurrentDeductionsFromRevenueProvisionIncreaseForAdditionsFromBusinessCombinations
Namespace Prefix:	alc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

No definition available.

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