Goodwill and Intangible Assets (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance				$ 165.1
Acquisition	[1]			1.3
Effect of exchange rate changes				5.0
Goodwill, ending balance		$ 171.4		171.4
Amortized intangible assets [Abstract]
Gross carrying value		151.4		151.4		$ 145.9
Accumulated amortization		(17.1)		(17.1)		(11.8)
Net intangible assets		134.3		134.3		134.1
Amortization expense		2.4	$ 0.4	4.8	$ 0.8
Estimated future amortization expense [Abstract]
Remainder of 2018		4.9		4.9
2019		9.6		9.6
2020		9.5		9.5
2021		8.9		8.9
2022		7.7		7.7
2023 & Beyond		93.7		93.7
Asia [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance				0.5
Acquisition	[1]			0.0
Effect of exchange rate changes				0.0
Goodwill, ending balance		0.5		0.5
Building HVAC [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance				13.7
Acquisition	[1]			0.0
Effect of exchange rate changes				0.7
Goodwill, ending balance		14.4		14.4
CIS [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance				150.9
Acquisition	[1]			1.3
Effect of exchange rate changes				4.3
Goodwill, ending balance		156.5		156.5
Customer Relationships [Member]
Amortized intangible assets [Abstract]
Gross carrying value		63.2		63.2		60.5
Accumulated amortization		(3.7)		(3.7)		(1.7)
Net intangible assets		59.5		59.5		58.8
Trade Names [Member]
Amortized intangible assets [Abstract]
Gross carrying value		60.0		60.0		58.4
Accumulated amortization		(9.1)		(9.1)		(7.2)
Net intangible assets		50.9		50.9		51.2
Acquired Technology [Member]
Amortized intangible assets [Abstract]
Gross carrying value		28.2		28.2		27.0
Accumulated amortization		(4.3)		(4.3)		(2.9)
Net intangible assets		$ 23.9		$ 23.9		$ 24.1

[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.