Stock-Based Compensation Plans - Summary of Nonvested TSRs (Details) - Total Shareholder Return Awards (TSRs)	6 Months Ended
Jun. 30, 2019 $ / shares shares
Number of Shares
Nonvested, beginning balance (in shares) \| shares	718,931
Granted (in shares) \| shares	436,674
Forfeited (in shares) \| shares	(18,050)
Nonvested, ending balance (in shares) \| shares	1,137,555
Weighted Average Grant Date Fair Value
Nonvested, beginning balance (in dollars per share) \| $ / shares	$ 29.25
Granted (in dollars per share) \| $ / shares	47.90
Forfeited (in dollars per share) \| $ / shares	36.06
Nonvested, ending balance (in dollars per share) \| $ / shares	$ 36.30

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
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- Definition

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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- Definition

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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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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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- Definition

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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-Publisher FASB
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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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The weighted average fair value of nonvested awards on equity-based plans excluding 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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