Stockholders' Equity (Summary of Purchases of Common Stock) (Details) - Share Repurchase Program Open [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended	18 Months Ended
Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2023
Stockholders Equity [Line Items]
Total Number of Shares Purchased	10,090	802	1,875	5,052	3,979	13,983	35,781
Dollar Value of Shares Purchased	$ 545	$ 57	$ 113	$ 318	$ 230	$ 589	$ 1,852
Average Price Paid per Share	$ 53.96	$ 71.69	$ 59.99	$ 63.07	$ 57.74	$ 42.15	$ 51.77

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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