Assets Held for Sale (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021
Assets Held for Sale [Abstract]
Impairment charges	$ 3.3		$ 0.0	$ 1.5	$ 0.0
ASSETS [Abstract]
Total assets held for sale	70.5			70.5		$ 107.6
LIABILITIES [Abstract]
Total liabilities held for sale	65.5			65.5		103.3
Liquid-Cooled Automotive Business [Member]
Assets Held for Sale [Abstract]
Impairment charges		$ (7.4)
Net carrying value of additions to property, plant and equipment	0.0	$ 0.0
ASSETS [Abstract]
Cash and cash equivalents	5.3			5.3
Trade accounts receivable - net	27.5			27.5
Inventories	18.6			18.6
Other current assets	13.9			13.9
Property, plant and equipment - net	117.4			117.4
Other noncurrent assets	7.4			7.4
Impairment of carrying value	(119.6)			(119.6)
Total assets held for sale	70.5			70.5
LIABILITIES [Abstract]
Short-term debt	15.0			15.0
Accounts payable	24.3			24.3
Accrued compensation and employee benefits	5.8			5.8
Other current liabilities	7.0			7.0
Pensions	9.9			9.9
Other noncurrent liabilities	3.5			3.5
Total liabilities held for sale	$ 65.5			65.5
Liquid-Cooled Automotive Business [Member] | Automotive [Member]
Assets Held for Sale [Abstract]
Impairment charges				$ 8.6
Liquid and Air-Cooled Automotive Businesses [Member]
ASSETS [Abstract]
Cash and cash equivalents						8.0
Trade accounts receivable - net						54.4
Inventories						24.7
Other current assets						12.8
Property, plant and equipment - net						164.0
Other noncurrent assets						8.8
Impairment of carrying value						(165.1)
Total assets held for sale						107.6
LIABILITIES [Abstract]
Short-term debt						5.0
Accounts payable						46.3
Accrued compensation and employee benefits						15.5
Other current liabilities						12.2
Pensions						17.8
Other noncurrent liabilities						6.5
Total liabilities held for sale						$ 103.3