Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Components of basic and diluted earnings per share [Abstract]
Net earnings attributable to Modine	$ 22.0	$ 17.0
Less: Undistributed earnings attributable to unvested shares	(0.1)	(0.2)
Net earnings available to Modine shareholders	$ 21.9	$ 16.8
Weighted-average shares outstanding - basic (in shares)	50.3	49.5
Effect of dilutive securities (in shares)	0.9	0.6
Weighted-average shares outstanding - diluted (in shares)	51.2	50.1
Earnings per share [Abstract]
Net earnings per share - basic (in dollars per share)	$ 0.43	$ 0.34
Net earnings per share - diluted (in dollars per share)	$ 0.43	$ 0.34
Stock Options [Member]
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)	0.4	0.5