Share Based Compensation (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Additional Share Based Compensation (Textual) [Abstract]
Total intrinsic value of options/SARs exercised	$ 4.9
Outstanding Stock Units	1,872,000	1,879,000
Share Based Compensation (Textual) [Abstract]
Shares of common stock authorized under the 2004 Plan	3,500,000
Common Stock, Capital Shares Reserved for Future Issuance	3,500,000
Share-based compensation expense	12.2	11.0	8.0
Tax benefits	4.6	4.1	3.0
Vesting period for the 2012 SAR grant	3 years
Portion of an award vesting for the 2012 SAR grant	1/3 vesting after each year
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Percentage	33.33%
Stock Option SAR Awards [Member]
Additional Share Based Compensation (Textual) [Abstract]
Total intrinsic value of options/SARs exercised	4.9	4.5	1.0
Unrecognized compensation expense	6.3
Weighted average period	1 year 8 months 15 days
Restricted Stock and Performance Share Awards [Member]
Additional Share Based Compensation (Textual) [Abstract]
Unrecognized compensation expense	$ 6.6
Weighted average period	1 year 9 months 22 days
Total Fair Value of Shares, Vested	$ 5,600,000.00	$ 2,700,000.00	$ 2,500,000.00
Phantom Stock Units [Member]
Additional Share Based Compensation (Textual) [Abstract]
Phantom Stock Units	20,722
Outstanding Stock Units	135,261
Stock Options/SARs Granted Since 2004 [Member]
Share Based Compensation (Textual) [Abstract]
Maximum granting period for stock option	7 years

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Maximum granting period for stock option.

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Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Percentage

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No definition available.

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- Definition

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.

+ 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 (h)(1)(i)

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-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-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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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 64

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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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As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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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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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

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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 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 maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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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.

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-Publisher FASB

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-Subparagraph b(1)(b)

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