Capital Stock (Shares Repurchased) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Equity [Abstract]
Shares Repurchased	0	3,600,395	5,026,512
Aggregate Cost of Shares	$ 0.0	$ 73.2	$ 136.5
Weighted Average Repurchase Price Per Share	$ 0.00	$ 20.33	$ 27.16

Equity impact of the cost of common shares repurchased during the period.

No definition available.

Name:	lgfa_SharesRepurchasedDuringPeriodValue
Namespace Prefix:	lgfa_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration