Shareholders' Equity - Data for stock options issued under the stock incentive plans (Details) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at January 1, 2019 \| shares	2,667,442
Exercised \| shares	(747,167)
Forfeited/Cancelled \| shares	(2,485)
Outstanding at December 31, 2019 \| shares	1,917,790
Options exercisable at December 31, 2019 \| shares	1,779,941
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Average exercise price, Beginning balance \| $ / shares	$ 48.20
Average exercise price, Exercised \| $ / shares	41.13
Average exercise price, Forfeited/Cancelled \| $ / shares	61.88
Average exercise price, Ending balance \| $ / shares	50.93
Average exercise price, Options exercisable \| $ / shares	$ 50.13
Average remaining contractual term, Options outstanding	3 years 8 months 12 days
Average remaining contractual term, Options exercisable	3 years 7 months 6 days
Aggregate intrinsic value, Options outstanding \| $	$ 113
Aggregate intrinsic value, Options exercisable \| $	$ 107

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Weighted average price of options that were either forfeited or expired.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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