Revenue Recognition, Impacts of Adopting New Accounting Guidance (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2018
Consolidated Statement of Operations [Abstract]
Net sales	$ 541.0	$ 512.7	$ 1,656.0	$ 1,536.5
Net earnings attributable to Modine	$ 18.0	$ (28.3)	$ 78.5	$ 4.6
Net earnings per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ 0.36	$ (0.57)	$ 1.55	$ 0.09
Diluted (in dollars per share)	$ 0.35	$ (0.57)	$ 1.53	$ 0.09
ASSETS [Abstract]
Inventories	$ 211.0		$ 211.0		$ 191.3
Other current assets	71.7		71.7		70.1
Deferred income taxes	96.5		96.5		96.9
LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract]
Deferred income taxes	9.1		9.1		9.9
Retained earnings	465.8		465.8		394.9
Impact of New Accounting Guidance [Member] | ASU 2014-09 [Member]
Consolidated Statement of Operations [Abstract]
Net sales	(5.6)		(5.2)
Net earnings attributable to Modine	$ (2.1)		$ (2.0)
Net earnings per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ (0.04)		$ (0.04)
Diluted (in dollars per share)	$ (0.04)		$ (0.04)
ASSETS [Abstract]
Inventories	$ 4.3		$ 4.3
Other current assets	(8.2)		(8.2)
Deferred income taxes	0.1		0.1
LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract]
Deferred income taxes	(0.9)		(0.9)
Retained earnings	(2.9)		(2.9)		$ 0.7
Results Without Impact of New Accounting Guidance [Member] | ASU 2014-09 [Member]
Consolidated Statement of Operations [Abstract]
Net sales	535.4		1,650.8
Net earnings attributable to Modine	$ 15.9		$ 76.5
Net earnings per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ 0.32		$ 1.51
Diluted (in dollars per share)	$ 0.31		$ 1.49
ASSETS [Abstract]
Inventories	$ 215.3		$ 215.3
Other current assets	63.5		63.5
Deferred income taxes	96.6		96.6
LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract]
Deferred income taxes	8.2		8.2
Retained earnings	$ 462.9		$ 462.9