Employee Stock Purchase Plan (ESPP) [Abstract]

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- Definition

The number of shares we expect to vest based on our current estimates of performance achievement under the Long-Term Incentive Program

+ References

No definition available.

+ Details

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
-Paragraph 28
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- Definition

Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

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No definition available.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

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

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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

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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

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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.

+ References

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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.

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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.

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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.

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- Definition

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

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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

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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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- 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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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- References

No definition available.

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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- Definition

For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

+ References

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- Definition

Weighted average price of options that were either forfeited or expired.

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- Definition

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

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- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

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- Definition

Number of options outstanding, including both vested and non-vested options.

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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.

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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- Definition

Number of share instruments newly issued under a share-based compensation plan.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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No definition available.

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- Definition

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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- Definition

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

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- Definition

Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Number of share options (or share units) exercised during the current period.

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Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation [Abstract]
Number of common shares available for grant under the incentive plan (in shares)	2,680,666
Share-based compensation	$ 20,425	$ 24,345	$ 16,643
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost		2,300
Tax benefits (expense) associated with stock-based compensation	$ 5,300	$ 8,500	$ 6,200
Stock option activity [Roll Forward]
Outstanding, beginning balance (in shares)	16,000
Granted (in shares)	0
Exercised (in shares)	0
Canceled (in shares)	0
Outstanding, ending balance (in shares)	16,000	16,000
Exercisable, ending balance (in shares)	16,000
Weighted average exercise price [Abstract]
Outstanding, beginning balance (in dollars per share)	$ 15.30
Granted (in dollars per share)	0.00
Exercised (in dollars per share)	0.00
Canceled (in dollars per share)	0.00
Outstanding, ending balance (in dollars per share)	15.30	$ 15.30
Exercisable, ending balance (in dollars per share)	$ 15.30
Weighted average remaining contractual life, stock option awards outstanding at end of year (in years)	2 years 6 months
Weighted average remaining contractual life, stock option awards exercisable at end of year (in years)	2 years 6 months
Aggregate intrinsic value of options outstanding, ending balance	$ 1,220
Aggregate intrinsic value of options exercisable ending balance	$ 1,220
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period	3 years
Employee Stock Purchase Plan (ESPP) [Abstract]
ESPP Stock Issued During Period (in shares)	30,000	38,000	34,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested during the year	$ 1,200	$ 46,000	$ 16,200
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 18,400
Unrecognized compensation expense, period for recognition (in months)	22 months
Equity Instruments Other than Options, Nonvested, Number of Shares[Roll Forward]
Balance at 12/31/2017 (in shares)	343,000
Granted (in shares)	290,000
Canceled (in shares)	(37,000)
Balance at 12/31/2018 (in shares)	582,000	343,000
Vested (in shares)	14,000
Weighted Average Grant Date Fair Value, Equity Instruments Other than Options [Abstract]
Balance at 12/31/2016 (in dollars per share)	$ 35.29
Granted (in dollars per share)	65.98	$ 42.15	$ 26.33
Vested (in dollars per share)	66.28
Canceled (in dollars per share)	41.37
Balance at 12/31/2017 (in dollars per share)	$ 49.48	$ 35.29
Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period	3 years
Restricted Stock [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period	5 years
Long-Term Incentive Program Awards [Member]
Equity Instruments Other than Options, Nonvested, Number of Shares[Roll Forward]
Balance at 12/31/2017 (in shares)	570,000
Granted (in shares)	100,000
Canceled (in shares)	(48,000)
Balance at 12/31/2018 (in shares)	426,000	570,000
Vested (in shares)	196,000
Weighted Average Grant Date Fair Value, Equity Instruments Other than Options [Abstract]
Balance at 12/31/2016 (in dollars per share)	$ 32.90
Granted (in dollars per share)	81.51
Vested (in dollars per share)	26.40
Canceled (in dollars per share)	41.90
Balance at 12/31/2017 (in dollars per share)	$ 46.35	$ 32.90
Long-Term Incentive Program Awards [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards vesting period	3 years
2015LTIPAward [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Issued in Period (in shares)	371,000
Fair value of shares vested during the year	$ 24,200
2016LTIPAwards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 400
Equity Instruments Other than Options, Nonvested, Number of Shares[Roll Forward]
NumberofShareExpectedtoVestBasedOnCurrentEstimatesofPerformanceAchievment	345,000
2017LTIPAwards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 3,400
Equity Instruments Other than Options, Nonvested, Number of Shares[Roll Forward]
NumberofShareExpectedtoVestBasedOnCurrentEstimatesofPerformanceAchievment	202,000
2018LTIPAwards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 8,600
Equity Instruments Other than Options, Nonvested, Number of Shares[Roll Forward]
NumberofShareExpectedtoVestBasedOnCurrentEstimatesofPerformanceAchievment	176,000