Number of Additional Shares To Be Granted If Maximum Perfornance Level Is Met or Exceeded

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- Definition

Reduction in Share Authorization if Maximum Performance Level is Met or Exceeded

+ References

No definition available.

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Tax Benefits

+ References

No definition available.

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Deferred Stock Unit, Vested in Period, Fair Value

+ References

No definition available.

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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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 718
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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Paragraph 2
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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 50
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- Definition

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.

+ References

No definition available.

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Long-term Equity-based Compensation - Activity Related to Nonvested Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of DSUs that vested during the years	$ 1.0	$ 0.9	$ 0.5
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested in Period, Total Fair Value	8.7	3.2	1.3
Income tax benefit from share-based compensation	$ 1.8	$ 1.1	$ 0.5
Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reduction in share authorization if maximum performance level is met or exceeded (shares)	981,900
Time Vested Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested Balance at Beginning of Year, Restricted Shares	130,247
Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value (per share)	$ 40.34
Grants in Period	249,422
Grants in Period, Weighted Average Grant Date Fair Value (per share)	$ 73.94
Vested in Period	(51,647)
Vested in Period, Weighted Average Grant Date Fair Value (per share)	$ 49.76
Forfeited in Period	(11,781)
Forfeited in Period, Weighted Average Grant Date Fair Value (per share)	$ 38.71
Nonvested Balance at End of Year, Restricted Shares	316,241	130,247
Nonvested at End of Year, Weighted Average Grant Date Fair Value (per share)	$ 65.36	$ 40.34
Performance Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested Balance at Beginning of Year, Restricted Shares	225,983
Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value (per share)	$ 36.90
Grants in Period	191,292
Grants in Period, Weighted Average Grant Date Fair Value (per share)	$ 56.88
Vested in Period		(77,244)
Vested in Period, Weighted Average Grant Date Fair Value (per share)		$ 37.63
Forfeited in Period	(12,731)
Forfeited in Period, Weighted Average Grant Date Fair Value (per share)	$ 47.71
Nonvested Balance at End of Year, Restricted Shares	327,300	225,983
Nonvested at End of Year, Weighted Average Grant Date Fair Value (per share)	$ 47.14	$ 36.90
Performance Period, 2017 to 2019 [Member] \| Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares To Be Granted If Maximum Performance Level Is Met or Exceeded	142,413
Reduction in share authorization if maximum performance level is met or exceeded (shares)	427,239
Performance Period, 2016 to 2018 [Member] \| Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares To Be Granted If Maximum Performance Level Is Met or Exceeded	80,999
Reduction in share authorization if maximum performance level is met or exceeded (shares)	242,997
Performance Period, 2015 to 2017 [Member] \| Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares To Be Granted If Maximum Performance Level Is Met or Exceeded	103,888
Reduction in share authorization if maximum performance level is met or exceeded (shares)	311,664