Background and Basis of Presentation (Share Repurchase Table) (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2021
Equity, Class of Treasury Stock [Line Items]
Aggregate cost of shares repurchased	$ 325,000,000	$ 650,000,000
January 2021 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Total number of shares repurchased (shares)	6.6	13.5
Aggregate cost of shares repurchased	$ 325,000,000	$ 650,000,000
Average price per share of shares repurchased (usd per share)	$ 49.21	$ 48.09

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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