Capital Stock - Restricted Share Unit Activity (Details) - Restricted Stock and Restricted Share Units (RSUs) shares in Millions	12 Months Ended
	Mar. 31, 2025 $ / shares shares
Old Lions Gate Class A Voting Shares
Number of Shares
Outstanding, beginning balance (in shares) | shares	0.1
Granted (in shares) | shares	0.1
Options exercised or restricted stock or RSUs vested (in shares) | shares	(0.1)
Forfeited or expired (in shares) | shares	0.0
Outstanding, ending balance (in shares) | shares	0.1
Weighted-Average Grant-Date Fair Value
Outstanding, beginning balance (in USD per share) | $ / shares	$ 9.27
Granted, weighted average grant date fair value (in USD per share) | $ / shares	8.20
Vested, Weighted Average Grant Date Fair Value (in usd per share) | $ / shares	9.20
Forfeited or expired, weighted average grant-date fair value (in USD per share) | $ / shares	0
Outstanding, ending balance (in USD per share) | $ / shares	$ 8.39
Old Lions Gate Class A Voting Shares | Lions Gate Entertainment Corp.
Number of Shares
Outstanding, beginning balance (in shares) | shares	0.1
Granted (in shares) | shares	0.1
Options exercised or restricted stock or RSUs vested (in shares) | shares	(0.1)
Forfeited or expired (in shares) | shares	0.0
Outstanding, ending balance (in shares) | shares	0.1
Weighted-Average Grant-Date Fair Value
Outstanding, beginning balance (in USD per share) | $ / shares	$ 9.27
Granted, weighted average grant date fair value (in USD per share) | $ / shares	8.24
Vested, Weighted Average Grant Date Fair Value (in usd per share) | $ / shares	9.20
Forfeited or expired, weighted average grant-date fair value (in USD per share) | $ / shares	0
Outstanding, ending balance (in USD per share) | $ / shares	$ 8.39
Old Lions Gate Class B Non-Voting Shares
Number of Shares
Outstanding, beginning balance (in shares) | shares	9.8
Granted (in shares) | shares	8.2
Options exercised or restricted stock or RSUs vested (in shares) | shares	(5.9)
Forfeited or expired (in shares) | shares	(1.0)
Outstanding, ending balance (in shares) | shares	11.1
Weighted-Average Grant-Date Fair Value
Outstanding, beginning balance (in USD per share) | $ / shares	$ 8.93
Granted, weighted average grant date fair value (in USD per share) | $ / shares	7.98
Vested, Weighted Average Grant Date Fair Value (in usd per share) | $ / shares	8.83
Forfeited or expired, weighted average grant-date fair value (in USD per share) | $ / shares	8.32
Outstanding, ending balance (in USD per share) | $ / shares	$ 8.17
Old Lions Gate Class B Non-Voting Shares | Lions Gate Entertainment Corp.
Number of Shares
Outstanding, beginning balance (in shares) | shares	13.3
Granted (in shares) | shares	10.5
Options exercised or restricted stock or RSUs vested (in shares) | shares	(8.3)
Forfeited or expired (in shares) | shares	(1.2)
Outstanding, ending balance (in shares) | shares	14.3
Weighted-Average Grant-Date Fair Value
Outstanding, beginning balance (in USD per share) | $ / shares	$ 8.71
Granted, weighted average grant date fair value (in USD per share) | $ / shares	7.98
Vested, Weighted Average Grant Date Fair Value (in usd per share) | $ / shares	8.79
Forfeited or expired, weighted average grant-date fair value (in USD per share) | $ / shares	8.29
Outstanding, ending balance (in USD per share) | $ / shares	$ 8.16