Receivables - Narrative (Details)		3 Months Ended	6 Months Ended
	Oct. 01, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) extension	Sep. 30, 2020 EUR (€) extension	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)
Purchasers
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Receivables facility, amount					$ 500,000,000		$ 600,000,000
Deferred purchase price for receivables	$ 0	$ 0	$ 0	$ 0	0
Availability under receivable facility					371,000,000
Drawn amount					452,000,000
Liability for excess cash proceeds					$ 81,000,000
Number of extensions | extension					1	1
Extension term			1 year
Gain (loss) on sale of receivables			$ 0
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Beginning balance	0	525,000,000		574,000,000
Transfers of receivables		0		1,214,000,000
Collections		0		(1,265,000,000)
Change in funding availability		0		2,000,000
Facility amendments		(525,000,000)		(525,000,000)
Ending balance		$ 0	$ 0	$ 0
Milano Purchasers
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Receivables facility, amount					$ 275,000,000
Drawn amount					$ 272,000,000
Number of extensions | extension					1	1
Extension term			1 year
Gain (loss) on sale of receivables			$ 0
Milano Purchasers | Subsequent Event
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Payments for commercial accounts receivable sold	272,000,000
DE Purchasers
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Receivables facility, amount					$ 175,000,000	€ 150,000,000		$ 102,000,000
Deferred purchase price for receivables	0		$ 0		0			$ 103,000,000
Availability under receivable facility					120,000,000
Drawn amount					$ 124,000,000
Number of extensions | extension					1	1
Extension term			1 year
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Beginning balance	$ 0		$ 103,000,000
Transfers of receivables			417,000,000
Collections			(420,000,000)
Change in funding availability			2,000,000
Facility amendments			(102,000,000)
Ending balance			$ 0
Receivable					$ 4,000,000