Compensation Plans - Stock Options (Details) - USD ($) shares in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options shares exercisable (in shares)	0.4	0.5
Total share-based compensation expense recognized	$ 23,000,000	$ 21,000,000	$ 18,000,000
Common Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options shares outstanding (in shares)	0.4	0.5
Proceeds received from options exercised	$ 3,000,000	$ 2,000,000	5,000,000
Total share-based compensation expense recognized	$ 0	$ 0	$ 0

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Number of options outstanding, including both vested and non-vested options.

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