Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Components of basic and diluted earnings per share [Abstract]
Net (loss) earnings attributable to Modine	$ (195.7)	$ 8.6	$ (8.6)	$ 1.2	$ (4.7)	$ 8.0	$ (195.7)	$ 4.5
Weighted-average shares outstanding - basic (in shares)	51.3			50.8			51.2	50.8
Effect of dilutive securities (in shares)	0.0			0.3			0.0	0.3
Weighted-average shares outstanding - diluted (in shares)	51.3			51.1			51.2	51.1
(Loss) earnings per share [Abstract]
Net (loss) earnings per share - basic (in dollars per share)	$ (3.81)			$ 0.02			$ (3.82)	$ 0.09
Net (loss) earnings per share - diluted (in dollars per share)	$ (3.81)			$ 0.02			$ (3.82)	$ 0.09
Antidilutive securities excluded from computation of earning per share [Abstract]
Potentially dilutive securities not included in computation of diluted net loss per share (in shares)	0.2						0.1
Stock Options [Member]
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	1.4			1.2			1.5	0.8
Restricted Stock [Member]
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	0.5			0.5			0.6	0.5