Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Basic Earnings Per Share [Abstract]
Net (loss) earnings attributable to Modine	$ (210.7)	$ (2.2)	$ 84.8
Less: Undistributed earnings attributable to unvested shares	0.0	0.0	(0.4)
Net (loss) earnings available to Modine shareholders	$ (210.7)	$ (2.2)	$ 84.4
Weighted-average shares outstanding - basic (in shares)	51.3	50.8	50.5
Net (loss) earnings per share - basic (in dollars per share)	$ (4.11)	$ (0.04)	$ 1.67
Diluted Earnings Per Share [Abstract]
Net (loss) earnings attributable to Modine	$ (210.7)	$ (2.2)	$ 84.8
Less: Undistributed earnings attributable to unvested shares	0.0	0.0	(0.2)
Net (loss) earnings available to Modine shareholders	$ (210.7)	$ (2.2)	$ 84.6
Weighted-average shares outstanding - basic (in shares)	51.3	50.8	50.5
Effect of dilutive securities (in shares)	0.0	0.0	0.8
Weighted-average shares outstanding - diluted (in shares)	51.3	50.8	51.3
Net (loss) earnings per share - diluted (in dollars per share)	$ (4.11)	$ (0.04)	$ 1.65
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Potentially dilutive securities not included in computation of diluted net loss per share (in shares)	0.2	0.3
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	1.0	1.1	0.4
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	0.4	0.5	0.3