Quarterly Financial Data (Unaudited) (Details) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Mar. 31, 2018 USD ($) $ / shares		Dec. 31, 2017 USD ($) $ / shares		Sep. 30, 2017 USD ($) $ / shares		Jun. 30, 2017 USD ($) $ / shares		Mar. 31, 2017 USD ($) $ / shares		Dec. 31, 2016 USD ($) $ / shares		Sep. 30, 2016 USD ($) $ / shares		Jun. 30, 2016 USD ($) $ / shares		Mar. 31, 2018 USD ($) $ / shares		Mar. 31, 2017 USD ($) Facility $ / shares		Mar. 31, 2016 USD ($) $ / shares
Selected quarterly financial information [Abstract]
Net sales	$ 566.6		$ 512.7		$ 508.3		$ 515.5		$ 488.3		$ 349.8		$ 317.7		$ 347.2		$ 2,103.1		$ 1,503.0		$ 1,352.5
Gross profit	96.5		85.4		86.1		88.5		85.1		59.0		48.0		62.3		356.5		254.4		233.6
Net earnings (loss)	18.0	[1]	(27.9)	[1]	16.3	[1]	17.4	[1]	8.1	[2]	1.9	[2]	(4.0)	[2]	8.9	[2]	23.8	[1]	14.9	[2]
Net earnings (loss) attributable to Modine	$ 17.6	[1]	$ (28.3)	[1]	$ 15.9	[1]	$ 17.0	[1]	$ 8.0	[2]	$ 1.7	[2]	$ (4.1)	[2]	$ 8.6	[2]	$ 22.2	[1]	$ 14.2	[2]	$ (1.6)
Net (loss) earnings per share attributable to Modine shareholders:
Basic (in dollars per share) | $ / shares	$ 0.35		$ (0.57)		$ 0.32		$ 0.34		$ 0.16		$ 0.04		$ (0.09)		$ 0.18		$ 0.44		$ 0.29		$ (0.03)
Diluted (in dollars per share) | $ / shares	$ 0.34		$ (0.57)		$ 0.31		$ 0.34		$ 0.16		$ 0.04		$ (0.09)		$ 0.18		$ 0.43		$ 0.29		$ (0.03)
Restructuring expenses	$ 4.5		$ 9.4		$ 0.4		$ 1.7		$ 4.9		$ 1.6		$ 2.1		$ 2.3		$ 16.0		$ 10.9		$ 16.6
Gain on sale of assets									0.8				1.2				0.0		2.0		0.0
Acquisition- and integration-related costs	0.6		1.0		$ 1.1		$ 1.6		3.2		$ 7.2		$ 3.0		$ 1.4
Impairment charges	1.2		1.3														2.5		$ 0.0		9.9
Number of closed manufacturing facilities sold | Facility																			2
Quarterly Financial Information [Line Items]
Provisional discrete tax charges																	38.0
Provision (benefit) for income taxes																	$ 39.5		$ 5.9		$ (8.9)
United States [Member]
Quarterly Financial Information [Line Items]
Provisional discrete tax charges	2.3		$ 35.7
Foreign Tax Jurisdictions [Member]
Quarterly Financial Information [Line Items]
Valuation allowance - deferred tax assets change in amount	$ (2.8)								$ 2.0

[1] During fiscal 2018, restructuring expenses totaled $1.7 million, $0.4 million, $9.4 million, and $4.5 million for the quarters ended June 30, 2017, September 30, 2017, December 31, 2017, and March 31, 2018, respectively (see Note 5). During the third quarter of fiscal 2018, the Company recorded a $1.3 million asset impairment charge related to a manufacturing facility in Austria (see Note 5). During the fourth quarter of fiscal 2018, the Company recorded a $1.2 million impairment charge related to intangible assets (see Note 12). During fiscal 2018, costs directly related to the acquisition and integration of Luvata HTS totaled $1.6 million, $1.1 million, $1.0 million, and $0.6 million for the quarters ended June 30, 2017, September 30, 2017, December 31, 2017, and March 31, 2018, respectively (see Note 2). The Company recorded charges totaling $35.7 million and $2.3 million resulting for certain income tax effects of recently-enacted U.S. tax legislation in the quarters ended December 31, 2017 and March 31, 2018, respectively (see Note 7). During the fourth quarter of fiscal 2018, the Company reversed a portion of a valuation allowance related to a foreign tax jurisdiction, and, as a result, recorded an income tax benefit of $2.8 million (see Note 7).

[2] During fiscal 2017, restructuring expenses totaled $2.3 million, $2.1 million, $1.6 million, and $4.9 million for the quarters ended June 30, 2016, September 30, 2016, December 31, 2016, and March 31, 2017, respectively (see Note 5). During fiscal 2017, the Company sold two previously-closed manufacturing facilities in its Americas segment and a facility in its Europe segment and recognized net gains totaling $1.2 million and $0.8 million in the quarters ended September 30, 2016 and March 31, 2017, respectively. During fiscal 2017, costs directly related to the acquisition and integration of Luvata HTS totaled $1.4 million, $3.0 million, $7.2 million, and $3.2 million for the quarters ended June 30, 2016, September 30, 2016, December 31, 2016, and March 31, 2017, respectively (see Note 2). During the fourth quarter of fiscal 2017, the Company recorded a deferred tax valuation allowance related to a foreign tax jurisdiction, and, as a result, recorded income tax expense of $2.0 million (see Note 7).