Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Future Amortization Of Acquisition-Related Intangibles) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Mar. 31, 2018
Finite-Lived Intangible Assets
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year		$ 19
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		22
Finite-Lived Intangible Assets, Amortization Expense, Year Two		22
Finite-Lived Intangible Assets, Amortization Expense, Year Three		22
Finite-Lived Intangible Assets, Amortization Expense, Year Four		8
Finite-Lived Intangible Assets, Amortization Expense, after Year Five		0
Finite-Lived Intangible Assets, Net	$ 107	$ 71	[1]
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year through after Year Five [Member]
Finite-Lived Intangible Assets
Finite-Lived Intangible Assets, Net	$ 93

[1] Derived from audited Consolidated Financial Statements.