Stock-Based Compensation Schedule of Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ 78	$ 305
May 2018 Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ 78	$ 305
Stock Repurchased and Retired During Period, Shares	0.7	3.2

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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