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Stock Incentive Plans (Details) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Stock Incentive Awards Units Outstanding (Roll Forward)
Units outstanding at beginning of period (in shares)	41.5
Granted (in shares)	13.3
Settled (in shares)	(13.5)
Forfeited or expired (in shares)	(2.7)
Units outstanding at end of period (in shares)	38.6	41.5
Stock Incentive Awards Weighted Average Grant Date Fair Value (Per Share) [Roll Forward]
Weighted-average grant date fair value, Units outstanding at beginning of period (in dollars per share)	$ 19.17
Weighted-average grant date fair value, granted (in dollars per share)	22.50
Weighted-average grant date fair value, settled (in dollars per share)	19.31
Weighted-average grant date fair value, forfeited or expired (in dollars per share)	27.23
Weighted-average grant date fair value, Units outstanding at end of period (in dollars per share)	$ 19.17	$ 19.17	$ 19.84
Remaining Contractual Term [Abstract]
Weighted Average Remaining Contractual Terms in years, Outstanding	10 months 24 days	10 months 24 days

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- Definition

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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No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

The weighted average grant date fair value of options and equity instruments other than options issued during the period, including both vested and nonvested instruments.

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No definition available.

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- Definition

Number of options and equity Instruments other than options outstanding, including both vested and non-vested instruments.

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No definition available.

+ Details

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- Definition

The weighted average grant date fair value of options and equity instruments other than options settled during the period.

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No definition available.

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Option and Non-Option Equity Instruments, Outstanding [Roll Forward]

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No definition available.

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- Definition

Number of option and non-option equity instruments exercised by participants.

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No definition available.

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- Definition

Number of shares under option and non-option equity instrument agreements that were either cancelled or expired.

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No definition available.

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- Definition

Net number of option and non-option equity instruments granted to participants.

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No definition available.

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- Definition

The weighted average fair value of nonvested awards on equity-based plans including option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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- Definition

Weighted average fair value as of the grant date of stock options and non-option equity instruments that were not exercised or put into effect as a result of the occurrence of a terminating event.

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No definition available.

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- Definition

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

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No definition available.

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