Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Components of basic and diluted earnings per share [Abstract]
Net earnings attributable to Modine	$ 1.2	$ (4.7)	$ 8.0	$ 18.0	$ 38.5	$ 22.0	$ 4.5	$ 78.5
Less: Undistributed earnings attributable to unvested shares	0.0			(0.1)			0.0	(0.3)
Net earnings available to Modine shareholders	$ 1.2			$ 17.9			$ 4.5	$ 78.2
Weighted-average shares outstanding - basic (in shares)	50.8			50.5			50.8	50.4
Effect of dilutive securities (in shares)	0.3			0.7			0.3	0.8
Weighted-average shares outstanding - diluted (in shares)	51.1			51.2			51.1	51.2
Earnings per share [Abstract]
Net earnings per share - basic (in dollars per share)	$ 0.02			$ 0.36			$ 0.09	$ 1.55
Net earnings per share - diluted (in dollars per share)	$ 0.02			$ 0.35			$ 0.09	$ 1.53
Stock Options [Member]
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	1.2			0.5			0.8	0.4