Represents the percentage of awards granted on target amount under an equity compensation plan.

No definition available.

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- Definition

The number of stock options that were forfeited during the reporting period.

+ References

No definition available.

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The weighted average grant-date fair value of unvested 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.

+ References

No definition available.

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The number of non-vested stock options that validly exist and are outstanding as of the balance sheet date.

+ References

No definition available.

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The number of stock options that vested during the reporting period.

+ References

No definition available.

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- Definition

The weighted average fair value as of grant date pertaining to a stock option award 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 terms of the arrangement.

+ References

No definition available.

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- Definition

Represents the percentage of awards earned upon cumulative total shareholder return achievement during the performance period under an equity compensation plan.

+ References

No definition available.

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- Definition

Represents the percentage of awards earned upon total shareholder return achievement in year one of the performance period under an equity compensation plan.

+ References

No definition available.

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- Definition

Represents the percentage of awards earned upon total shareholder return achievement in year three of the performance period under an equity compensation plan.

+ References

No definition available.

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- Definition

Represents the percentage of awards earned upon total shareholder return achievement in year two of the performance period under an equity compensation plan.

+ References

No definition available.

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- Definition

Represents the percentage of awards granted upon cumulative total shareholder return achievement during the performance period under an equity compensation plan.

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No definition available.

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- Definition

Represents the percentage of awards issued upon cumulative total shareholder return achievement during the performance period under an equity compensation plan.

+ References

No definition available.

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- Definition

Represents the percentage of number of shares to be earned under awards of an equity compensation plan.

+ References

No definition available.

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

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No definition available.

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Unrecognized cost of unvested options awarded to employees as compensation.

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No definition available.

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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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-Name Accounting Standards Codification

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

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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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-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

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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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-SubTopic 10

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-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

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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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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

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(iii)

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.D.2)

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-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(i)

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section D

-Subsection 2

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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-Paragraph 2

-Subparagraph (f)(2)(ii)

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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-Publisher FASB

-Name Accounting Standards Codification

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-Paragraph 2

-Subparagraph (f)(2)(iv)

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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.

+ References

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- Definition

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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-Publisher FASB

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-Paragraph 2

-Subparagraph (c)(1)(iv)(4)

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Weighted average grant-date fair value of non-vested options outstanding.

+ References

No definition available.

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

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

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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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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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No definition available.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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No definition available.

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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Aggregate value of stock related to Restricted Stock Awards issued during the period.

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Equity Incentive Plan (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 03, 2015	Mar. 04, 2014	May 22, 2013	Dec. 31, 2013
Assumptions used to value the stock options granted
Expected term	2 years 9 months 29 days	2 years 9 months 29 days
Expected volatility (as a percent)	25.51%	32.98%
Expected annual dividend (as a percent)	0.00%	0.00%
Risk-free rate (as a percent)	1.02%	0.64%
2010 Plan
Equity Incentive Plan
Shares of common stock that were available for issuance pursuant to the 2010 Plan	3,318,347				6,000,000
Stock Options
Number of Shares Subject to Options
Options outstanding at the beginning of the period (in shares)	758,095
Exercised (in shares)	(20,287)
Forfeited (in shares)	(562)
Expired (in shares)	(282)
Options outstanding at the end of the period (in shares)	736,964
Weighted Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)	20.94
Exercised (in dollars per share)	22.00
Forfeited (in dollars per share)	15.23
Expired (in dollars per share)	15.23
Options outstanding at the end of the period (in dollars per share)	20.91
Number of Shares Subject to Options
Unvested balance at the beginning of the period (in shares)						283,964
Forfeited (in shares)	(562)
Vested (in shares)	(116,780)
Unvested balance at the end of the period (in shares)	166,622					283,964
Weighted Average Fair Value at Grant
Unvested balance at the beginning of the period (in dollars per share)						$ 7.75
Forfeited (in dollars per share)	4.89
Vested (in dollars per share)	6.43
Unvested balance at the end of the period (in dollars per share)	8.67					$ 7.75
Compensation cost not yet recognized
Unearned compensation	1.6
Stock Options \| Weighted Average
Compensation cost not yet recognized
Vesting period	1 year 4 months 24 days
Restricted Awards
Restricted Awards
Grant date value	8.4
Unvested balance at the beginning of the period (in shares)						394,016
Granted (in shares)	176,697
Forfeited (in shares)	(2,749)
Vested (in shares)	(111,143)
Unvested balance at the end of the period (in shares)	456,821					394,016
Weighted Average Fair Value at Grant
Unvested balance at the beginning of the period (in dollars per share)						$ 29.10
Granted (in dollars per share)	47.49
Forfeited (in dollars per share)	28.17
Vested (in dollars per share)	27.24
Unvested balance at the end of the period (in dollars per share)	36.67					$ 29.10
Compensation cost not yet recognized
Unearned compensation	15.1
Restricted Awards \| Weighted Average
Compensation cost not yet recognized
Vesting period	2 years 6 months
Restricted awards
Restricted Awards
Granted (in shares)	176,269
RSUs
Restricted Awards
Granted (in shares)	428
PSAs
Restricted Awards
Grant date value			2.7	1.6
Granted (in shares)			78,551	91,335
Forfeited (in shares)	0
Compensation cost not yet recognized
Unearned compensation	3.6
Percentage of awards eligible to be earned upon TSR achievement in year one of the performance period	20.00%
Percentage of awards eligible to be earned upon TSR achievement in year two of the performance period	20.00%
Percentage of awards earned upon TSR achievement in year three of the performance period	20.00%
Percentage of awards eligible to be earned upon cumulative TSR achievement over the three-year performance period	40.00%
Percentage of awards granted initially on target amount			175.00%
Percentage of awards issued initially on target amount	150.00%
Percentage of awards granted on target amount				150.00%
PSAs \| Weighted Average
Compensation cost not yet recognized
Vesting period	2 years 4 months 24 days
PSAs \| Minimum
Compensation cost not yet recognized
Percentage of number of shares to be earned under awards			25.00%	0.00%
PSAs \| Maximum
Compensation cost not yet recognized
Percentage of number of shares to be earned under awards			175.00%	150.00%