Acquisition of Luvata HTS (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended	9 Months Ended
		Nov. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017	Dec. 31, 2017		Dec. 31, 2016	Mar. 31, 2017
Business Acquisition [Line Items]
Acquired goodwill					$ 1.3	$ 1.3	[1]
Allocation of Purchase price for Acquisition [Abstract]
Goodwill			$ 172.2			172.2			$ 165.1
Net earnings per share attributable to Modine Shareholders [Abstract]
Interest expense			6.3	$ 4.5		19.5		$ 10.5
Commercial and Industrial Solutions ("CIS") [Member]
Business Acquisition [Line Items]
Net sales						451.6		34.7
Operating income						14.3		(0.3)
Acquired goodwill	[1]					1.3
Allocation of Purchase price for Acquisition [Abstract]
Goodwill			$ 157.2			$ 157.2			$ 150.9
Luvata HTS [Member]
Business Acquisition [Line Items]
Acquired ownership interest by the entity		100.00%
Purchase price allocation, net of cash		$ 388.2
Allocation of Purchase price for Acquisition [Abstract]
Cash and cash equivalents		27.4
Trade accounts receivable		86.1
Inventories		55.0
Property, plant and equipment		120.4
Intangible assets		130.2
Goodwill		151.9
Other assets		39.1
Accounts payable		(73.7)
Accrued compensation and employee benefits		(24.3)
Deferred income taxes		(39.5)
Pensions		(14.3)
Other liabilities		(42.7)
Purchase price		$ 415.6
Pro Forma Information [Abstract]
Net sales				439.5				1,393.3
Net earnings attributable to Modine				$ 8.5				$ 26.8
Net earnings per share attributable to Modine Shareholders [Abstract]
Basic (in dollars per share)				$ 0.17				$ 0.54
Diluted (in dollars per share)				$ 0.17				$ 0.53
Amortization and depreciation expense				$ 3.2
Interest expense				3.5
Acquisition related transaction costs				8.6				$ 8.6
Inventory purchase accounting adjustment				$ 2.9

[1] During the first six months of fiscal 2018, the Company recorded a $1.3 million increase to goodwill as a result of measurement period adjustments made in connection with purchase accounting for the acquisition of Luvata HTS. See Note 2 for additional information.