Deferred Compensation Plan Assets, Colleteral For Plan Benefits

No definition available.

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Namespace Prefix:	mnk_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Number of Life Insurance Contract Held in Rabbi Trust

+ References

No definition available.

+ Details

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Namespace Prefix:	mnk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
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Period Type:	duration

- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_RetirementPlanNameAxis=mnk_DefinedContributionPlan401KMember
Namespace Prefix:
Data Type:	na
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Retirement Plans (Defined Contribution Plan) (Details) $ in Millions	1 Months Ended	6 Months Ended		11 Months Ended	12 Months Ended
	Dec. 29, 2023 USD ($)	Dec. 30, 2022 USD ($)	Jun. 16, 2022 USD ($)	Nov. 14, 2023 USD ($)	Dec. 29, 2023 USD ($) contract	Dec. 30, 2022 USD ($) contract	Dec. 31, 2021 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Number of Life Insurance Contract Held in Rabbi Trust \| contract					48	55
Deferred Compensation Plan Assets, Collateral For Plan Benefits	$ 7.3				$ 7.3
Foreign Plan
Defined Contribution Plan Disclosure [Line Items]
Deferred Compensation Plan Assets, Collateral For Plan Benefits		$ 7.3				$ 7.3
Defined Contribution Plan, 401 K [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match					50.00%
Defined Contribution Plan, Cost	$ 2.5	$ 7.8	$ 9.6	$ 18.6			$ 22.2