Capital Stock - Schedule of Share-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Share-Based Compensation Expense [Line Items]
Total Legacy Lionsgate Studios employee share-based compensation expense	$ 29.1	$ 39.8	$ 42.5
Corporate allocation of share-based compensation	23.9	15.0	26.7
Share-based payment arrangement, total	53.0	54.8	69.2
Impact of accelerated vesting on equity awards	4.9	7.7	4.2
Total share-based compensation expense	57.9	62.5	73.4
Tax impact	(14.0)	(15.1)	(17.8)
Reduction in net income	43.9	47.4	55.6
Stock options
Share-Based Compensation Expense [Line Items]
Total Legacy Lionsgate Studios employee share-based compensation expense	0.8	1.7	2.3
Restricted share units and other share-based compensation
Share-Based Compensation Expense [Line Items]
Total Legacy Lionsgate Studios employee share-based compensation expense	27.7	37.7	39.3
Share appreciation rights
Share-Based Compensation Expense [Line Items]
Total Legacy Lionsgate Studios employee share-based compensation expense	$ 0.6	$ 0.4	$ 0.9

Corporate Allocation Of Share Based Compensation

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors, certain consultants qualifying for treatment as employees, including the impact of compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

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Share-Based Payment Arrangement, Expense, Including Corporate Allocations

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
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Amount, after tax, of expense for award under share-based payment arrangement.

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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.

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Amount of additional cost recognized for award under share-based payment arrangement from occurrence of event accelerating recognition of cost.

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