Goodwill and Intangible Assets, Net - Narrative - Intangible Assets (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2017
Goodwill [Line Items]
Amortization expense of intangible assets	$ 123,000,000	$ 102,000,000	$ 370,000,000	$ 332,000,000
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Estimated annual amortization expense, remainder of 2018	113,000,000		113,000,000
Estimated annual amortization expense, 2019	437,000,000		437,000,000
Estimated annual amortization expense, 2020	421,000,000		421,000,000
Estimated annual amortization expense, 2021	403,000,000		403,000,000
Estimated annual amortization expense, 2022	370,000,000		370,000,000
Estimated annual amortization expense, thereafter	2,350,000,000		2,350,000,000
Distribution Solutions
Goodwill [Line Items]
Accumulated goodwill impairment losses	350,000,000		350,000,000		$ 0
Technology Solutions
Goodwill [Line Items]
Accumulated goodwill impairment losses	$ 0		$ 0		$ 290,000,000