Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

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-Name Accounting Standards Codification

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- Definition

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.

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-Publisher FASB

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

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Share-Based Compensation Plans - Summary of information about stock options (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period			0
$12.03 - $12.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	$ 12.03
Range of Exercise Prices, Upper Range	$ 12.49
Stock Options Outstanding and Exercisable, Number (in shares)	70,000
Stock Options Outstanding and Exercisable, Weighted Average Remaining Life	3 months 29 days
Stock Options Outstanding and Exercisable, Weighted Average Exercise Price	$ 12.30
$20.42 - $22.53
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	$ 20.42
Range of Exercise Prices, Upper Range	$ 22.53
Stock Options Outstanding and Exercisable, Number (in shares)	190,000
Stock Options Outstanding and Exercisable, Weighted Average Remaining Life	2 years 1 month 10 days
Stock Options Outstanding and Exercisable, Weighted Average Exercise Price	$ 21.09
$24.48 - $29.26
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	$ 24.48
Range of Exercise Prices, Upper Range	$ 29.26
Stock Options Outstanding and Exercisable, Number (in shares)	226,774
Stock Options Outstanding and Exercisable, Weighted Average Remaining Life	3 years 6 months 26 days
Stock Options Outstanding and Exercisable, Weighted Average Exercise Price	$ 26.18
$36.03
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Range	$ 36.03
Stock Options Outstanding and Exercisable, Number (in shares)	80,000
Stock Options Outstanding and Exercisable, Weighted Average Remaining Life	5 months 19 days
Stock Options Outstanding and Exercisable, Weighted Average Exercise Price	$ 36.03
Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares granted (in shares)	0	0	11,702
Compensation expense	$ 0	$ 0	$ 100
Non-Employee Director
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares granted (in shares)	0	0	12,264