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Share-Based Compensation - Performance shares and performance units activity (Details)	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Performance Shares
Unvested Shares:
Unvested balance, beginning of year (in shares) | shares	1,400,914
Performance shares and units granted | shares	548,906
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(98,438)
Unvested balance, end of year (in shares) | shares	1,851,382
Weighted Average Grant Date Fair Value:
Unvested balance, beginning of year, weighted average grant date fair value | $ / shares	$ 30.29
Weighted average grant date fair value | $ / shares	44.17
Vested, weighted average grant date fair value | $ / shares	0
Forfeited, weighted average grant date fair value | $ / shares	30.01
Unvested balance, end of year, weighted average grant date fair value | $ / shares	$ 34.42
Performance Units
Unvested Shares:
Unvested balance, beginning of year (in shares) | shares	23,767
Performance shares and units granted | shares	8,298
Vested (in shares) | shares	0
Forfeited (in shares) | shares	0
Unvested balance, end of year (in shares) | shares	32,065
Weighted Average Grant Date Fair Value:
Unvested balance, beginning of year, weighted average grant date fair value | $ / shares	$ 29.75
Weighted average grant date fair value | $ / shares	44.17
Vested, weighted average grant date fair value | $ / shares	0
Forfeited, weighted average grant date fair value | $ / shares	0
Unvested balance, end of year, weighted average grant date fair value | $ / shares	$ 33.48

X

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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-SubTopic 10
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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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