Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Mar. 31, 2020		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2020		Mar. 31, 2019		Mar. 31, 2018
Quarterly Financial Data [Abstract]
Net sales	$ 472.9		$ 473.4		$ 500.2		$ 529.0		$ 556.7		$ 541.0		$ 548.9		$ 566.1		$ 1,975.5		$ 2,212.7		$ 2,103.1
Gross profit	74.9		73.5		75.7		83.4		91.6		91.7		87.9		94.3		307.5		365.5		356.5
Net earnings (loss)	(6.4)	[1]	1.0	[1]	(4.8)	[1]	8.2	[1]	6.4	[2]	18.3	[2]	38.7	[2]	22.5	[2]	(2.0)	[1]	85.9	[2]
Net earnings (loss) attributable to Modine	$ (6.7)	[1]	$ 1.2	[1]	$ (4.7)	[1]	$ 8.0	[1]	$ 6.3	[2]	$ 18.0	[2]	$ 38.5	[2]	$ 22.0	[2]	$ (2.2)	[1]	$ 84.8	[2]	$ 22.2
Net earnings (loss) per share attributable to Modine shareholders [Abstract]
Basic (in dollars per share)	$ (0.13)		$ 0.02		$ (0.09)		$ 0.16		$ 0.12		$ 0.36		$ 0.76		$ 0.43		$ (0.04)		$ 1.67		$ 0.44
Diluted (in dollars per share)	$ (0.13)		$ 0.02		$ (0.09)		$ 0.16		$ 0.12		$ 0.35		$ 0.75		$ 0.43		$ (0.04)		$ 1.65		$ 0.43
Restructuring expenses	$ 5.5		$ 2.6		$ 2.3		$ 1.8		$ 8.9		$ 0.5				$ 0.2		$ 12.2		$ 9.6		$ 16.0
Gain (loss) on sale of assets																	0.8		(1.7)		0.0
Income tax expense related to legal entity restructuring			2.7														2.9
Impairment charges	8.6										0.4						8.6		0.4		2.5
Income tax expense (benefit) related to US Tax Reform											2.2		$ (24.4)						(7.7)
Change in deferred tax asset valuation allowances	4.1		3.0										1.0		$ (2.0)
AIAC Air Conditioning South Africa (Pty) Ltd [Member]
Net earnings (loss) per share attributable to Modine shareholders [Abstract]
Gain (loss) on sale of assets													$ (1.7)
VTS [Member]
Quarterly Financial Data [Abstract]
Net sales																	1,177.2		$ 1,351.7		$ 1,295.7
Net earnings (loss) per share attributable to Modine shareholders [Abstract]
Gain (loss) on sale of assets			0.8														0.8
Impairment charges																	$ 7.5
Costs associated with review of strategic alternatives	$ 5.0		$ 14.0		$ 11.9		$ 8.3		$ 5.9		$ 1.2

[1] During fiscal 2020, restructuring expenses totaled $1.8 million, $2.3 million, $2.6 million, and $5.5 million for the quarters ended June 30, 2019, September 30, 2019, December 31, 2019, and March 31, 2020, respectively (see Note 5).  During the third quarter of fiscal 2020, the Company sold a previously-closed manufacturing facility in Germany and, as a result, recorded a gain of $0.8 million (see Note 1).  During the fourth quarter of fiscal 2020, the Company recorded asset impairment charges totaling $8.6 million related to long-lived assets and goodwill (see Note 5 and Note 14). During fiscal 2020, costs associated with the Company’s review of strategic alternatives for the VTS segment’s automotive business totaled $8.3 million, $11.9 million, $14.0 million, and $5.0 million for the quarters ended June 30, 2019, September 30, 2019, December 31, 2019, and March 31, 2020, respectively. During fiscal 2020, the Company adjusted its valuation allowances on deferred tax assets in the U.S and in Brazil.  As a result, the Company recorded net income tax charges totaling $3.0 million and $4.1 million in the third and fourth quarters, respectively. Also during fiscal 2020, the Company recorded a net income tax charge totaling $2.9 million, $2.7 million of which was recorded in the third quarter, as a result of legal entity restructuring completed in preparation of a potential sale of the automotive business (see Note 7).

[2] During fiscal 2019, restructuring expenses totaled $0.2 million, $0.5 million, and $8.9 million for the quarters ended June 30, 2018, December 31, 2018, and March 31, 2019, respectively (see Note 5).  During the second quarter of fiscal 2019, the Company sold its South African business within the BHVAC segment and, as a result, recorded a loss of $1.7 million (see Note 1).  During the third quarter of fiscal 2019, the Company recorded a $0.4 million impairment charge related to a manufacturing facility in Austria (see Note 5). During the third and fourth quarter of fiscal 2019, the Company incurred $1.2 million and $5.9 million of costs associated with its review of strategic alternatives for the VTS segment’s automotive business. The Company’s income tax benefit for fiscal 2019 includes net benefits of $24.4 million and net charges of $2.2 million in the second and third quarters, respectively, related to the Tax Act and the recognition of foreign tax credits (see Note 7).  During fiscal 2019, the Company adjusted its valuation allowances on deferred tax assets related to two separate subsidiaries in China and, as a result, recorded a $2.0 million income tax benefit and a $1.0 million income tax charge in the first and second quarters, respectively (see Note 7).