CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Net sales	$ 484.3	$ 473.4	$ 1,293.5	$ 1,502.6
Cost of sales	401.6	399.9	1,083.9	1,270.0
Gross profit	82.7	73.5	209.6	232.6
Selling, general and administrative expenses	56.1	63.5	151.6	194.4
Restructuring expenses	0.9	2.6	7.0	6.7
Impairment charges	134.4	0.0	134.4	0.0
Gain on sale of assets	0.0	(0.8)	0.0	(0.8)
Operating (loss) income	(108.7)	8.2	(83.4)	32.3
Interest expense	(4.6)	(5.6)	(15.2)	(17.3)
Other (expense) income - net	(0.5)	0.1	(1.0)	(2.3)
(Loss) earnings before income taxes	(113.8)	2.7	(99.6)	12.7
Provision for income taxes	(81.6)	(1.7)	(95.3)	(8.3)
Net (loss) earnings	(195.4)	1.0	(194.9)	4.4
Net (earnings) loss attributable to noncontrolling interest	(0.3)	0.2	(0.8)	0.1
Net (loss) earnings attributable to Modine	$ (195.7)	$ 1.2	$ (195.7)	$ 4.5
Net (loss) earnings per share attributable to Modine shareholders:
Basic (in dollars per share)	$ (3.81)	$ 0.02	$ (3.82)	$ 0.09
Diluted (in dollars per share)	$ (3.81)	$ 0.02	$ (3.82)	$ 0.09
Weighted-average shares outstanding:
Basic (in shares)	51.3	50.8	51.2	50.8
Diluted (in shares)	51.3	51.1	51.2	51.1