Share-Based Compensation (Stock Option Awards) (Details) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Options	451,025	544,225
Options Outstanding, Weighted-Avg. Remaining Contractual Life (Years)	4 years 6 months
Options Outstanding, Weighted-Avg. Exercise Price (in dollars per share)	$ 47.22	$ 46.09
Options Exercisable, Number of Options	408,775
Options Exercisable, Weighted-Avg. Exercise Price (in dollars per share)	$ 48.59
$33.61-40.53 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit (in dollars per share)	$ 33.61
Range of Exercise Prices, upper limit (in dollars per share)	$ 40.53
Options Outstanding, Number of Options		131,525
Options Outstanding, Weighted-Avg. Remaining Contractual Life (Years)	6 years 1 month 6 days
Options Outstanding, Weighted-Avg. Exercise Price (in dollars per share)		$ 34.21
Options Exercisable, Number of Options		89,275
Options Exercisable, Weighted-Avg. Exercise Price (in dollars per share)		$ 34.36
$47.61-51.51 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit (in dollars per share)	$ 47.61
Range of Exercise Prices, upper limit (in dollars per share)	$ 51.51
Options Outstanding, Number of Options		166,000
Options Outstanding, Weighted-Avg. Remaining Contractual Life (Years)	4 years 7 months 6 days
Options Outstanding, Weighted-Avg. Exercise Price (in dollars per share)		$ 49.64
Options Exercisable, Number of Options		166,000
Options Exercisable, Weighted-Avg. Exercise Price (in dollars per share)		$ 49.64
$52.13-58.83 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit (in dollars per share)	$ 52.13
Range of Exercise Prices, upper limit (in dollars per share)	$ 58.83
Options Outstanding, Number of Options		153,500
Options Outstanding, Weighted-Avg. Remaining Contractual Life (Years)	2 years 10 months 24 days
Options Outstanding, Weighted-Avg. Exercise Price (in dollars per share)		$ 55.73
Options Exercisable, Number of Options		153,500
Options Exercisable, Weighted-Avg. Exercise Price (in dollars per share)		$ 55.73

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)

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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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.

+ References

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- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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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 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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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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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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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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