Goodwill And Intangible Assets, Net - Narrative - Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 108	$ 125	$ 329	$ 384
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Estimated annual amortization expense, 2016	86		86
Estimated annual amortization expense, 2017	378		378
Estimated annual amortization expense, 2018	360		360
Estimated annual amortization expense, 2019	327		327
Estimated annual amortization expense, 2020	302		302
Estimated annual amortization expense, thereafter	$ 1,651		$ 1,651