Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Components of basic and diluted earnings per share [Abstract]
Net (loss) earnings attributable to Modine	$ (4.7)	$ 8.0	$ 38.5	$ 22.0	$ 3.3	$ 60.5
Less: Undistributed earnings attributable to unvested shares	0.0		(0.1)		0.0	(0.2)
Net (loss) earnings available to Modine shareholders	$ (4.7)		$ 38.4		$ 3.3	$ 60.3
Weighted-average shares outstanding - basic (in shares)	50.8		50.5		50.8	50.4
Effect of dilutive securities (in shares)	0.0		0.9		0.3	0.9
Weighted-average shares outstanding - diluted (in shares)	50.8		51.4		51.1	51.3
(Loss) earnings per share [Abstract]
Net (loss) earnings per share - basic (in dollars per share)	$ (0.09)		$ 0.76		$ 0.07	$ 1.19
Net (loss) earnings per share - diluted (in dollars per share)	$ (0.09)		$ 0.75		$ 0.06	$ 1.18
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	0.3
Stock Options [Member]
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	0.9		0.4		0.8	0.4