Note 1 - Basis of Presentation - Reconciliation of Basic to Diluted Weighted-average Shares Outstanding (Details) - shares shares in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Weighted-average shares outstanding-basic (in shares)	93	93	92	93
Common stock equivalents for restricted shares (in shares)	0	1	0	1
Weighted-average shares outstanding-diluted (in shares)	93	94	92	94

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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