Borrowings, Extension Term

No definition available.

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- Definition

Borrowings, Issuance Percentage

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Borrowings Maturity, Term

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Borrowings, Number Of Extension Options

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of interest and other costs that an entity incurs in connection with the borrowing of funds.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
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-URIDate 2020-01-01

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of outstanding funds that the entity is obligated to repay.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_55&doctype=Standard
-URIDate 2020-01-01

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The interest rate on borrowings. [Refer: Borrowings]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 7
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_7&doctype=Standard
-URIDate 2020-01-01

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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- Definition

The gain (loss) arising from the difference between the carrying amount of the financial liability extinguished and the measurement of the consideration paid (equity instruments issued) to the creditor. [Refer: Carrying amount [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRIC
-Number 19
-IssueDate 2020-01-01
-Paragraph 11
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRIC&num=19&code=ifrs-tx-2020-en-r&anchor=para_11&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from borrowings obtained. [Refer: Borrowings]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2020-01-01
-Paragraph 17
-Subparagraph c
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-URIDate 2020-01-01

+ Details

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

- Definition

The amount of undrawn borrowing facilities that may be available for future operating activities and to settle capital commitments. [Refer: Capital commitments]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2020-01-01
-Paragraph 50
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-URIDate 2020-01-01

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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- Details

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- Details

Name:	ifrs-full_BorrowingsByNameAxis=alc_RevolvingFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Data Type:	na
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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Non-current and current financial debts - Additional information (Details)					1 Months Ended	12 Months Ended
	May 27, 2020 USD ($)	Sep. 23, 2019 USD ($)	Apr. 02, 2019 USD ($)	Mar. 06, 2019 USD ($) extension	Feb. 28, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Apr. 09, 2019 USD ($)
Disclosure of detailed information about borrowings [line items]
Interest expense						$ 94,000,000	$ 81,000,000	$ 10,000,000
Borrowings, interest rate	2.60%
Proceeds from borrowings	$ 750,000,000
Financial debts						4,118,000,000	3,479,000,000		$ 3,500,000,000
Write-off of deferred debt issuance cost		$ 4,000,000				0	$ 4,000,000	$ 0
Debt issuance costs [Member]
Disclosure of detailed information about borrowings [line items]
Financial debts		(15,000,000)
Bridge facility [member]
Disclosure of detailed information about borrowings [line items]
Notional amount				$ 1,500,000,000
Borrowings, term				364 days
Borrowings, number of extension options \| extension				2
Borrowings, extension term				180 days
Facility A [member]
Disclosure of detailed information about borrowings [line items]
Notional amount				$ 500,000,000
Borrowings, term				3 years
Facility B [member]
Disclosure of detailed information about borrowings [line items]
Notional amount				$ 800,000,000
Borrowings, term				5 years
Facility C [member]
Disclosure of detailed information about borrowings [line items]
Notional amount				$ 400,000,000
Borrowings, term				5 years
Revolving facility [member]
Disclosure of detailed information about borrowings [line items]
Notional amount				$ 1,000,000,000.0		1,000,000,000.0
Borrowings, term				5 years
Bridge and other term loans [member]
Disclosure of detailed information about borrowings [line items]
Proceeds from borrowings			$ 3,200,000,000
Senior notes [member] \| Borrowings discount [Member]
Disclosure of detailed information about borrowings [line items]
Financial debts		$ 7,000,000
Senior notes due 2026 [member]
Disclosure of detailed information about borrowings [line items]
Borrowings, interest rate		2.75%
Notional amount		$ 500,000,000
Borrowings, issuance percentage		99.50%
Senior notes due 2029 [member]
Disclosure of detailed information about borrowings [line items]
Borrowings, interest rate		3.00%
Notional amount		$ 1,000,000,000
Borrowings, issuance percentage		99.60%
Senior notes due 2049 [member]
Disclosure of detailed information about borrowings [line items]
Borrowings, interest rate		3.80%
Notional amount		$ 500,000,000
Borrowings, issuance percentage		99.80%
Senior notes due 2030 [Member]
Disclosure of detailed information about borrowings [line items]
Borrowings, interest rate	2.60%
Notional amount	$ 750,000,000
Proceeds from borrowings	$ 750,000,000
Borrowings, issuance percentage	99.843%
Borrowing costs incurred	$ 5,000,000
Senior notes due 2030 [Member] \| Borrowings discount [Member]
Disclosure of detailed information about borrowings [line items]
Financial debts	$ 1,000,000
Local bilateral facilities [member]
Disclosure of detailed information about borrowings [line items]
Borrowings, term					1 year
Financial debts					$ 150,000,000
Local bilateral facilities, japan [member]
Disclosure of detailed information about borrowings [line items]
Financial debts					$ 101,000,000
Undrawn borrowing facilities						$ 115,000,000
Weighted average [member]
Disclosure of detailed information about borrowings [line items]
Borrowings, interest rate						2.30%	2.90%