Stock-Based Compensation - Stock Options, Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
Mar. 22, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Stock Ownership Plan (ESOP) Disclosures
Options granted (in shares)		0	0	0
Expected dividend yield (as a percent)		3.20%	3.20%	3.30%
Expected life (in years)		7 years	7 years	7 years
Intrinsic value of stock options exercised		$ 7	$ 3	$ 7
Cash received from stock options exercised		6	5	11
Tax benefit from exercised stock options		1	$ 1	$ 1
Aggregate intrinsic value of exercisable options		$ 9
Stock options
Employee Stock Ownership Plan (ESOP) Disclosures
Minimum volatility rate				23.00%
Maximum volatility rate				29.00%
Expected dividend yield (as a percent)				0.00%
Minimum risk free rate				2.34%
Maximum risk free rate				2.51%
Departure rate				10.00%
Minimum exercise ratio				220.00%
Maximum exercise ratio				280.00%
Expected life (in years)	5 years 4 months 24 days

Share Based Compensation Arrangement By Share Based payment Award FairValue Assumtions Exercise Ratios Maximum .

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Share Based Compensation Arrangement By Share Based payment Award FairValue Assumtions Exercise Ratios Minimum

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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

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Restrictions on equity-based instruments during the vesting period, such as the inability to transfer unvested awards, are not taken into account in estimating the fair value of the award. However, restrictions that remain in effect after an award is vested, such as the inability to transfer or hedge vested options or a prohibition on the sale of outstanding vested shares (or other type of equity) for a period of time, affect the estimate of an award's fair value.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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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.

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Gross number of share options (or share units) granted during the period.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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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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