Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																12 Months Ended
	Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2019		Mar. 31, 2018		Mar. 31, 2017
Basic Earnings Per Share [Abstract]
Net earnings attributable to Modine	$ 6.3	[1]	$ 18.0	[1]	$ 38.5	[1]	$ 22.0	[1]	$ 17.6	[2]	$ (28.3)	[2]	$ 15.9	[2]	$ 17.0	[2]	$ 84.8	[1]	$ 22.2	[2]	$ 14.2
Less: Undistributed earnings attributable to unvested shares																	(0.4)		(0.2)		(0.2)
Net earnings available to Modine shareholders																	$ 84.4		$ 22.0		$ 14.0
Weighted-average shares outstanding - basic (in shares)																	50.5		49.9		47.8
Net earnings per share - basic (in dollars per share)	$ 0.12		$ 0.36		$ 0.76		$ 0.43		$ 0.35		$ (0.57)		$ 0.32		$ 0.34		$ 1.67		$ 0.44		$ 0.29
Diluted Earnings Per Share [Abstract]
Net earnings attributable to Modine	$ 6.3	[1]	$ 18.0	[1]	$ 38.5	[1]	$ 22.0	[1]	$ 17.6	[2]	$ (28.3)	[2]	$ 15.9	[2]	$ 17.0	[2]	$ 84.8	[1]	$ 22.2	[2]	$ 14.2
Less: Undistributed earnings attributable to unvested shares																	(0.2)		(0.1)		(0.1)
Net earnings available to Modine shareholders																	$ 84.6		$ 22.1		$ 14.1
Weighted-average shares outstanding - basic (in shares)																	50.5		49.9		47.8
Effect of dilutive securities (in shares)																	0.8		1.0		0.5
Weighted-average shares outstanding - diluted (in shares)																	51.3		50.9		48.3
Net earnings per share - diluted (in dollars per share)	$ 0.12		$ 0.35		$ 0.75		$ 0.43		$ 0.34		$ (0.57)		$ 0.31		$ 0.34		$ 1.65		$ 0.43		$ 0.29
Stock Options [Member]
Antidilutive securities excluded from computation of earning per share [Abstract]
Antidilutive securities excluded from computation of earning per share (in shares)																	0.4		0.2		0.8

[1] 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 6). 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 6). 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 8). 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 8).

[2] 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 6). 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 6). During the fourth quarter of fiscal 2018, the Company recorded a $1.2 million impairment charge related to intangible assets (see Note 14). The Company recorded income tax charges totaling $35.7 million and $2.3 million during the third and fourth quarters of fiscal 2018, respectively, related to the Tax Act (see Note 8). 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 8).