Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 173.8
Effect of exchange rate changes			(4.1)
Goodwill, ending balance	$ 169.7		169.7
Amortized intangible assets [Abstract]
Gross carrying value	146.0		146.0		$ 150.0
Accumulated amortization	(23.8)		(23.8)		(20.1)
Net intangible assets	122.2		122.2		129.9
Amortization expense	2.3	$ 2.4	4.6	$ 4.8
Estimated future amortization expense [Abstract]
Remainder of fiscal 2019	4.5		4.5
2020	9.0		9.0
2021	8.0		8.0
2022	8.0		8.0
2023	8.0		8.0
2024	8.0		8.0
VTS [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance			0.5
Effect of exchange rate changes			0.0
Goodwill, ending balance	0.5		0.5
BHVAC [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance			15.0
Effect of exchange rate changes			(0.9)
Goodwill, ending balance	14.1		14.1
CIS [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance			158.3
Effect of exchange rate changes			(3.2)
Goodwill, ending balance	155.1		155.1
Customer Relationships [Member]
Amortized intangible assets [Abstract]
Gross carrying value	62.4		62.4		64.2
Accumulated amortization	(7.4)		(7.4)		(5.7)
Net intangible assets	55.0		55.0		58.5
Trade Names [Member]
Amortized intangible assets [Abstract]
Gross carrying value	59.3		59.3		60.6
Accumulated amortization	(11.9)		(11.9)		(10.8)
Net intangible assets	47.4		47.4		49.8
Acquired Technology [Member]
Amortized intangible assets [Abstract]
Gross carrying value	24.3		24.3		25.2
Accumulated amortization	(4.5)		(4.5)		(3.6)
Net intangible assets	$ 19.8		$ 19.8		$ 21.6