Executive Deferred Compensation Plan (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation arrangement with individual, description	Employees age 18 and older are eligible to contribute to the plan starting the first day of employment
Executive [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of matching contribution maximum (in hundredths)	1000.00%
Percentage of compensation deferred, maximum (in hundredths)	8000.00%
Percentage of bonus deferred, maximum (in hundredths)	10000.00%
Deferred compensation arrangement with individual, description	The Company has an executive deferred compensation plan for select management personnel.
Compensation expense	$ 1.2	$ 1.7	$ 3.4
Compensation cost accrued related to executive deferred compensation plan	22.1	17.3
Investment in Rabbi Trust	$ 18.6	$ 14.9

The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

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The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

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- Definition

Description of the deferred compensation arrangement, including fixed amounts and determinable awards, or the method for determining payments and awards, the timing of such payments and awards, and any requisite service or performance criteria, as of the balance sheet date.

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- Definition

The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit.

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