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Note 4 - Stock-based Compensation - Additional Information Regarding Stock Option Exercises (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2022 | Mar. 31, 2021
Intrinsic value of stock options exercised | $ 42 | $ 23
Cash received from option exercises | 15 | 30
Treasury shares repurchased for employee payroll taxes | (5) | (6)
Tax benefit realized from option exercises | 5 | 4
Aggregate grant-date fair value of stock options vested | $ 13 | $ 14

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- Definition Represents the aggregate grant-date fair value of stock options vested during the period. + References No definition available. + Details
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- Definition Represents the amount of treasury shares repurchased for employee payroll taxes. + References No definition available. + Details
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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 + Details
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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 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901 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 + Details
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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 -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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