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Note 4 - Stock Options and Other Stock Plans - Additional Information Regarding Stock Option Exercises (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Intrinsic value of stock options exercised	$ 84	$ 120	$ 193
Cash received from option exercises	58	95	130
Treasury shares repurchased for employee payroll taxes	(15)	(24)	(37)
Tax benefit realized from option exercises	16	28	48
Aggregate grant-date fair value of stock options vested	$ 14	$ 15	$ 15

X

- Definition

Represents the aggregate grant-date fair value of stock options vested during the period.

+ References

No definition available.

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- Definition

Represents the amount of treasury shares repurchased for employee payroll taxes.

+ References

No definition available.

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- Definition

Amount of tax benefit from exercise of option under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901

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- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
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