Segment and Geographic Information, Total Assets by Segment (Details) - USD ($) $ in Millions		12 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Segment and Geographic Information [Abstract]
Total assets		$ 1,276.7	$ 1,536.1
Impairment charges		166.8	8.6	$ 0.4
Change in deferred tax asset valuation allowance		22.0	9.2
Automotive [Member]
Segment and Geographic Information [Abstract]
Impairment charges		1.7
Corporate [Member]
Segment and Geographic Information [Abstract]
Total assets		17.5
Change in deferred tax asset valuation allowance		103.3
Operating Segments [Member] | BHVAC [Member]
Segment and Geographic Information [Abstract]
Total assets		110.8	102.3
Operating Segments [Member] | CIS [Member]
Segment and Geographic Information [Abstract]
Total assets		609.2	617.7
Operating Segments [Member] | HDE [Member]
Segment and Geographic Information [Abstract]
Total assets		438.7	417.4
Operating Segments [Member] | Automotive [Member]
Segment and Geographic Information [Abstract]
Total assets	[1]	124.2	272.5
Corporate and Eliminations [Member]
Segment and Geographic Information [Abstract]
Total assets	[2]	$ (6.2)	$ 126.2

[1] During fiscal 2021, the Company recorded impairment charges totaling $166.8 million within the Automotive segment, primarily related to the property, plant and equipment of the liquid- and air-cooled automotive businesses, which are classified as held for sale as of March 31, 2021.  See Note 2 for additional information.

[2] At March 31, 2021, Corporate assets totaled $17.5 million and were more than offset by eliminations for intercompany balances, including accounts receivable.  During fiscal 2021, the Company recorded income tax charges totaling $103.3 million, which established a full valuation allowance on deferred tax assets in the U.S that are recorded at Corporate.  See Note 8 for additional information.