Stock-Based Compensation (Stock Appreciation Rights Award Activity) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SARs, Weighted Average Exercise Price [Roll Forward]
Stock-Settled SARs, Outstanding	203,540
Cash-Settled SARs, Outstanding	94,174
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards, expiration period	10 years
SARs Activity [Roll Forward]
Outstanding, Beginning	375,104	389,686	320,336
Granted	7,733	132,566	145,018
Exercised	(85,123)	(147,148)	(75,668)
Outstanding, Ending	297,714	375,104	389,686
Exercisable	88,751	56,938	110,292
SARs, Weighted Average Exercise Price [Roll Forward]
Oustanding, Beginning (in usd per share)	$ 24.03	$ 20.81	$ 20.17
Granted (in usd per share)	$ 47.74	$ 29.56	$ 21.22
Exercised (in usd per share)	$ 22.09	$ 20.47	$ 18.91
Oustanding, Ending (in usd per share)	$ 25.20	$ 24.03	$ 20.81
Exercisable (in usd per share)	$ 23.15	$ 20.95	$ 20.70

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Number of non-option equity instruments exercised by participants.

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Net number of non-option equity instruments granted to participants.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ References

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)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Number of cash-settled stock appreciation rights outstanding.

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- Definition

Number of stock-settled stock appreciation rights outstanding.

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