Acquisitions - Narrative (Details) $ / shares in Units, $ in Millions				3 Months Ended		11 Months Ended	12 Months Ended
	Jun. 05, 2024 USD ($) film	May 13, 2024 USD ($) $ / shares shares	Dec. 27, 2023 USD ($)	Mar. 31, 2025 USD ($) shares	Mar. 31, 2024 USD ($) shares	Mar. 31, 2025 USD ($) shares	Mar. 31, 2025 USD ($) shares		Mar. 31, 2024 USD ($) shares
Business Acquisition [Line Items]
Number of films acquired | film	46
Variable interest entity, initial consolidation, gain (loss)	$ 0.0
Total assets				$ 5,115.2	$ 5,103.0	$ 5,115.2	$ 5,115.2		$ 5,103.0
Liabilities				$ 6,038.1	$ 6,129.9	6,038.1	6,038.1		$ 6,129.9
Proceeds from reverse recapitalization transaction						330.0
Proceeds from the PIPE investment		$ 254.3				$ 254.3	$ 254.3
Proceeds due from the PIPE investment		20.0
Common shares, shares issued (in shares) | shares				288,700,000	253,400,000	288,700,000	288,700,000		253,400,000
Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Number of films acquired | film	46
Variable interest entity, initial consolidation, gain (loss)							$ 0.0
Total assets				$ 6,822.1	$ 7,092.7	$ 6,822.1	6,822.1		$ 7,092.7
Liabilities				7,081.1	7,279.9	7,081.1	7,081.1		7,279.9
Proceeds from reverse recapitalization transaction		330.0
Proceeds from the PIPE investment		254.3
Proceeds due from the PIPE investment		20.0
Proceeds from issuance or sale of equity							278.2
Reduction of noncontrolling interest							(278.2)
Non-controlling Interests | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Reduction of noncontrolling interest		$ 100.2					100.2	[1]
Accumulated Other Comprehensive Income | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Reduction of noncontrolling interest							11.3
SEAC Sponsor Options
Business Acquisition [Line Items]
Common shares, shares issued (in shares) | shares		2,200,000
SEAC Sponsor Options | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Common shares, shares issued (in shares) | shares		2,200,000
Sponsor Option Agreement
Business Acquisition [Line Items]
Common stock, par or stated value per share (in dollars per share) | $ / shares		$ 0.0001
Sponsor Option Agreement | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Common stock, par or stated value per share (in dollars per share) | $ / shares		0.0001
Sponsor Securities Repurchase
Business Acquisition [Line Items]
Shares issued, price per share (in dollars per share) | $ / shares		1.00
Sponsor Securities Repurchase | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Shares issued, price per share (in dollars per share) | $ / shares		$ 16.05
Variable Interest Entity, Primary Beneficiary
Business Acquisition [Line Items]
Total assets				63.3		63.3	63.3
Liabilities				7.7		7.7	7.7
Variable Interest Entity, Primary Beneficiary | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Total assets				63.3		63.3	63.3
Liabilities				7.7		$ 7.7	7.7
CP LG Library Holdings, LLC
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 68.6
CP LG Library Holdings, LLC | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	68.6
CP LG Library Holdings, LLC | Film and Television Library
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	48.3
CP LG Library Holdings, LLC | Film and Television Library | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 48.3
CP LG Library Holdings, LLC
Business Acquisition [Line Items]
Ownership percentage by noncontrolling owners	49.00%
CP LG Library Holdings, LLC | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Ownership percentage by noncontrolling owners	49.00%
Studio Business | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Ownership percentage by noncontrolling owners		12.20%
Ownership percentage		87.80%
Studio Business | Screaming Eagle
Business Acquisition [Line Items]
Ownership percentage by noncontrolling owners		12.20%
Studio Business | Screaming Eagle | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Ownership percentage by noncontrolling owners		12.20%
CP LG Library Holdings, LLC
Business Acquisition [Line Items]
Purchase price consideration	$ 35.0
Percentage of voting interests acquired	51.00%
CP LG Library Holdings, LLC | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Purchase price consideration	$ 35.0
Percentage of voting interests acquired	51.00%
eOne
Business Acquisition [Line Items]
Purchase price consideration			$ 373.1	$ 373.1
Revenue of acquiree since acquisition date, actual					113.8
Earnings or loss of acquiree since acquisition date, actual					4.9
Acquisition related costs							1.0		9.4
Pro forma impairment of goodwill and trade name at eOne									296.2
eOne | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Purchase price consideration			$ 373.1
Revenue of acquiree since acquisition date, actual					113.8
Earnings or loss of acquiree since acquisition date, actual					$ 4.9
Acquisition related costs							$ 1.0		9.4
Pro forma impairment of goodwill and trade name at eOne									$ 296.2
eOne | Film and Television Library | Minimum
Business Acquisition [Line Items]
Weighted average useful life (in years)			5 years
eOne | Film and Television Library | Minimum | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Weighted average useful life (in years)			5 years
eOne | Film and Television Library | Maximum
Business Acquisition [Line Items]
Weighted average useful life (in years)			10 years
eOne | Film and Television Library | Maximum | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Weighted average useful life (in years)			10 years
eOne | Trade Names
Business Acquisition [Line Items]
Weighted average useful life (in years)			5 years
eOne | Trade Names | Lions Gate Entertainment Corp.
Business Acquisition [Line Items]
Weighted average useful life (in years)			5 years

[1] Excludes redeemable noncontrolling interests, which are reflected in temporary equity (see Note 11).