Revenue Recognition, Impacts of Adopting New Accounting Guidance (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018
Consolidated Statement of Operations [Abstract]
Net sales	$ 566.1	$ 515.5
Net earnings attributable to Modine	$ 22.0	$ 17.0
Net earnings per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ 0.43	$ 0.34
Diluted (in dollars per share)	$ 0.43	$ 0.34
ASSETS [Abstract]
Inventories	$ 203.7		$ 191.3
Other current assets	68.6		70.1
Deferred income taxes	94.9		96.9
LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract]
Deferred income taxes	9.1		9.9
Retained earnings	409.3		394.9
Impact of New Accounting Guidance [Member] | ASU 2014-09 [Member]
Consolidated Statement of Operations [Abstract]
Net sales	(1.2)
Net earnings attributable to Modine	$ (0.3)
Net earnings per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ (0.01)
Diluted (in dollars per share)	$ (0.01)
ASSETS [Abstract]
Inventories	$ 2.8
Other current assets	(4.2)
Deferred income taxes	0.1
LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract]
Deferred income taxes	(0.2)
Retained earnings	(1.1)		$ 0.7
Results Without Impact of New Accounting Guidance [Member] | ASU 2014-09 [Member]
Consolidated Statement of Operations [Abstract]
Net sales	564.9
Net earnings attributable to Modine	$ 21.7
Net earnings per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ 0.43
Diluted (in dollars per share)	$ 0.42
ASSETS [Abstract]
Inventories	$ 206.5
Other current assets	64.4
Deferred income taxes	95.0
LIABILITIES AND SHAREHOLDERS' EQUITY [Abstract]
Deferred income taxes	8.9
Retained earnings	$ 408.2