Capital Stock - Unrecognized Compensation Cost (Details) $ in Millions	12 Months Ended
	Mar. 31, 2025 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Unrecognized Compensation Cost	$ 46.0
Lions Gate Entertainment Corp.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Unrecognized Compensation Cost	58.6
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Unrecognized Compensation Cost	$ 0.9
Weighted Average Remaining Years	8 months 12 days
Stock options | Lions Gate Entertainment Corp.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Unrecognized Compensation Cost	$ 0.9
Weighted Average Remaining Years	8 months 12 days
Restricted Stock and Restricted Share Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Unrecognized Compensation Cost	$ 45.1
Weighted Average Remaining Years	1 year 6 months
Restricted Stock and Restricted Share Units (RSUs) | Lions Gate Entertainment Corp.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Unrecognized Compensation Cost	$ 57.7
Weighted Average Remaining Years	1 year 6 months