Segment and Geographic Information, Net Sales, Gross Profit, and Operating Income by Segment (Details) - USD ($) $ 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
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales	$ 556.7	$ 541.0	$ 548.9	$ 566.1	$ 566.6	$ 512.7	$ 508.3	$ 515.5	$ 2,212.7	$ 2,103.1		$ 1,503.0
Gross profit	$ 91.6	$ 91.7	$ 87.9	$ 94.3	$ 96.5	$ 85.4	$ 86.1	$ 88.5	$ 365.5	$ 356.5		$ 254.4
Gross profit (% of sales)									16.50%	17.00%		16.90%
Operating income									$ 109.7	$ 92.2		$ 42.3
Luvata HTS [Member] | Selling, General and Administrative Expenses [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Acquisition and integration related costs										4.3		14.8
VTS [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									1,351.7	1,295.7		1,152.2
CIS [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									707.6	675.7		231.8
BHVAC [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									212.4	191.2		171.6
Total Segments [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									2,271.7	2,162.6		1,555.6
Operating Segments [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									2,212.7	2,103.1		1,503.0
Gross profit									$ 365.2	$ 356.8		$ 262.0
Gross profit (% of sales)									16.10%	16.50%		16.80%
Operating income									$ 145.1	$ 133.0		$ 92.5
Operating Segments [Member] | VTS [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									1,298.9	1,239.3		1,099.9
Gross profit									$ 186.9	$ 201.0		$ 182.0
Gross profit (% of sales)									13.80%	15.50%		15.80%
Operating income									$ 64.8	$ 84.2		$ 68.4
Operating Segments [Member] | CIS [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									704.7	674.4		231.5
Gross profit									$ 114.9	$ 97.8		$ 32.2
Gross profit (% of sales)									16.20%	14.50%		13.90%
Operating income									$ 53.4	$ 28.5		$ 10.9
Operating Segments [Member] | BHVAC [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									209.1	189.4		171.6
Gross profit									$ 63.4	$ 58.0		$ 47.8
Gross profit (% of sales)									29.90%	30.30%		27.80%
Operating income									$ 26.9	$ 20.3		$ 13.2
Corporate and Eliminations [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									(59.0)	(59.5)		(52.6)
Gross profit									$ 0.3	$ (0.3)	[1]	$ (7.6)	[1]
Gross profit (% of sales)									0.00%	0.00%	[1]	0.00%	[1]
Operating income									$ (35.4)	$ (40.8)	[1]	$ (50.2)	[1]
Corporate and Eliminations [Member] | Cost of Sales [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Inventory purchase accounting adjustment												4.3
Inter-segment Sales [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									59.0	59.5		52.6
Inter-segment Sales [Member] | VTS [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									52.8	56.4		52.3
Inter-segment Sales [Member] | CIS [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									2.9	1.3		0.3
Inter-segment Sales [Member] | BHVAC [Member]
Net sales, gross profit, operating income and total assets by segment [Abstract]
Net sales									$ 3.3	$ 1.8		$ 0.0

[1] During fiscal 2018 and 2017, the Company recorded $4.3 million and $14.8 million, respectively, of costs incurred directly related to the acquisition and integration of Luvata HTS within SG&A expenses at Corporate. During fiscal 2017, the Company recorded $4.3 million in cost of sales related to an inventory purchase accounting adjustment at Corporate, as the impact was excluded from the Company's measure of segment operating performance. In addition, the operating loss for Corporate includes certain research and development costs, legal, finance and other general corporate and central services expenses, and other costs that are either not directly attributable to an operating segment or not considered when management evaluates segment performance.