Segment and Geographic Information, Capital Expenditures and Depreciation and Amortization Expense by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Total capital expenditures	$ 73.9	$ 71.0	$ 64.4
Total depreciation and amortization expense	76.9	76.7	58.3
Operating Segments [Member] | VTS [Member]
Segment Reporting Information [Line Items]
Total capital expenditures	56.2	61.4	59.5
Total depreciation and amortization expense	49.5	48.2	46.2
Operating Segments [Member] | CIS [Member]
Segment Reporting Information [Line Items]
Total capital expenditures	16.4	9.0	3.4
Total depreciation and amortization expense	23.9	24.3	7.9
Operating Segments [Member] | BHVAC [Member]
Segment Reporting Information [Line Items]
Total capital expenditures	1.3	0.6	1.5
Total depreciation and amortization expense	$ 3.5	$ 4.2	$ 4.2