Debt and Credit Arrangements Interest Rate Swaps (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Debt Instrument
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	$ 300.0
Ending date hedged in interest rate cash flow hedge	Dec. 31, 2013
Cash paid to settle interest rate swap agreements	24.0
Derivative Instruments, Loss Recognized in Income, Net	2.1
Interest Rate Cash Flow Hedge Liability at Fair Value	21.9
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion, Net	(1.0)	(9.2)
Cash Flow Hedge Loss to be Reclassified within Twelve Months	(1.8)
10.00% Senior Unsecured Notes due 2017
Debt Instrument
Write off of Unamortized Discount	$ 7.3
Stated Interest Rate	10.00%
3.75% Senior Notes due 2023
Debt Instrument
Stated Interest Rate	3.75%

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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- Definition

Cash paid to settle interest rate swap agreements

+ References

No definition available.

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- Definition

Ending date for which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions.

+ References

No definition available.

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- Definition

Write off of Unamortized Discount

+ References

No definition available.

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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

-Publisher FASB

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- Definition

Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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