Description Of Business And Basis Of Presentation New Lease Standard Balance Sheet at Period Start (Details) - USD ($) $ in Millions	Mar. 31, 2020	Apr. 01, 2019	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets	$ 321	$ 307	$ 313
Other assets	305	329	114
Accrued and other current liabilities	1,052	1,099	1,052
Other liabilities	$ 216	294	$ 132
Balance Sheet Impact at Period End [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets		(6)
Other assets		215
Accrued and other current liabilities		47
Other liabilities		$ 162