Fair Value of Debt (Details) (Fair Value, Inputs, Level 2 [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
9.25% Notes [Member] \| Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	$ 337.9	$ 337.5
9.25% Notes [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	360.4	377.4
7.875% Notes [Member] \| Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	0	300.0
7.875% Notes [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	0	310.1
7.75% Notes [Member] \| Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	200.0	200.0
7.75% Notes [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	220.5	216.5
6.625% Notes [Member] \| Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	550.0	550.0
6.625% Notes [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	562.4	555.5
6.25% Notes [Member] \| Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	400.0	0
6.25% Notes [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	$ 409.0	$ 0

Fair Value of Debt (Details) (Fair Value, Inputs, Level 2 [Member], USD $)
In Millions, unless otherwise specified

Sep. 30, 2013

Dec. 31, 2012

9.25% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

$ 337.9

$ 337.5

9.25% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

360.4

377.4

7.875% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

300.0

7.875% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

310.1

7.75% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

200.0

7.75% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

220.5

216.5

6.625% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

550.0

6.625% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

562.4

555.5

6.25% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

400.0

6.25% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Notes payable

$ 409.0

$ 0

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References+ Details