Sale of Receivables (Details)	3 Months Ended	9 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 EUR (€) extension	Dec. 31, 2019 USD ($) extension	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Extension term		1 year
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Transfers of receivables			$ 464,000,000
Operating cash flow effect			(57,000,000)
Collections			521,000,000
Purchasers
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Receivables facility, amount						$ 750,000,000	$ 600,000,000
Deferred purchase price receivable	$ 598,000,000	$ 0	598,000,000		$ 0		$ 525,000,000
Availability under receivable facility					639,000,000
Drawn amount					$ 650,000,000
Number of extensions | extension				1	1
Gain (loss) on sale of receivables		0
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Deferred purchase price receivable, Beginning balance	540,000,000	574,000,000	233,000,000
Transfers of receivables	1,199,000,000	1,214,000,000	4,175,000,000
Collections	(1,215,000,000)	(1,265,000,000)	(3,115,000,000)
Change in funding availability	74,000,000	2,000,000	(236,000,000)
Facility amendments	0	(525,000,000)	(457,000,000)
Fair value adjustment	0	0	(2,000,000)
Deferred purchase price receivable, Ending balance	$ 598,000,000	0	$ 598,000,000
DE Purchasers
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Receivables facility, amount				€ 200,000,000	$ 225,000,000
Deferred purchase price receivable		$ 120,000,000			120,000,000
Availability under receivable facility					117,000,000
Drawn amount					$ 109,000,000
Number of extensions | extension				1	1
Extension term		1 year
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Deferred purchase price receivable, Beginning balance		$ 0
Transfers of receivables		534,000,000
Collections		(427,000,000)
Change in funding availability		13,000,000
Deferred purchase price receivable, Ending balance		$ 120,000,000
Receivable					$ 8,000,000