Stock-based Compensation (Schedule of SARs Oustanding) (Details) (SARs [Member], USD $)	12 Months Ended
Dec. 31, 2013
SARs [Member]
SARs
Balance at December 31, 2012	351,881
Granted	85,943
Exercised	94,379
Balance at December 31, 2013	343,445
Exercisable at December 31, 2013	166,317
Weighted Average Exercise Price
Balance at December 31, 2012	$ 27.52
Granted	$ 42.14
Exercised	$ 24.67
Balance at December 31, 2013	$ 32.01
Exercisable at December 31, 2013	$ 26.58

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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

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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.

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

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

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