Fair Value Measurements - Schedule of Carrying Values and Fair Values of Company’s Outstanding Debt, Film Related Obligations, and Interest Rate Swaps (Details) - USD ($) $ in Millions	Sep. 30, 2024	Mar. 31, 2024
Intercompany Revolver | Carrying Value | Revolving Credit Facility
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	$ 80.4	$ 0.0
Intercompany Revolver | Fair Value | Revolving Credit Facility | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	80.4	0.0
LGTV Revolver | Carrying Value | Revolving Credit Facility
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	417.6	569.9
LGTV Revolver | Fair Value | Revolving Credit Facility | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	421.5	575.0
LGTV Term Loan A | Carrying Value | Term Loans
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Loans, fair value disclosure	312.9	396.6
LGTV Term Loan A | Fair Value | Term Loans | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Loans, fair value disclosure	312.9	397.3
LGTV Term Loan B | Carrying Value | Term Loans
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Loans, fair value disclosure	249.7	816.9
LGTV Term Loan B | Fair Value | Term Loans | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Loans, fair value disclosure	249.7	818.1
eOne IP Credit Facility | Carrying Value | Line of Credit
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	334.0	0.0
eOne IP Credit Facility | Fair Value | Line of Credit | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	340.0	0.0
LG IP Credit Facility | Carrying Value | Line of Credit
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	447.9	0.0
LG IP Credit Facility | Fair Value | Line of Credit | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	455.0	0.0
Production Loans | Carrying Value | Production Loans
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Loans, fair value disclosure	1,239.4	1,286.2
Production Loans | Fair Value | Production Loans | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Loans, fair value disclosure	1,244.8	1,292.2
Production Tax Credit Facility | Carrying Value | Line of Credit
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	259.6	258.7
Production Tax Credit Facility | Fair Value | Line of Credit | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Line of credit facility, fair value disclosure	260.0	260.0
Backlog Facility and Other | Carrying Value | Secured Debt
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Backlog Facility and Other, IP Credit Facility and Financing component of interest rate swaps, fair value disclosure	271.9	285.4
Backlog Facility and Other | Fair Value | Secured Debt | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Backlog Facility and Other, IP Credit Facility and Financing component of interest rate swaps, fair value disclosure	273.2	287.3
Film Library Facility | Carrying Value | Secured Debt
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Backlog Facility and Other, IP Credit Facility and Financing component of interest rate swaps, fair value disclosure	92.3	107.6
Film Library Facility | Fair Value | Secured Debt | Level 2
Fair Value, Carrying Values and Fair Values of Assets and Liabilities Not Required to be Carried at Fair Value on a Recurring Basis [Line Items]
Backlog Facility and Other, IP Credit Facility and Financing component of interest rate swaps, fair value disclosure	$ 94.2	$ 109.9