Note 4 - Stock-based Compensation - Stock-based Compensation (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Stock options	$ 4	$ 4	$ 13	$ 12
Retention awards	23	24	58	57
Total stock-based compensation, before tax	33	32	87	84
Excess income tax benefits from equity compensation plans	3	2	13	9
Employee Stock [Member]
ESPP	$ 6	$ 4	$ 16	$ 15

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
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Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

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