Fair Value Measurements (Schedule of Carrying Values and Estimated Fair Values of Debt Instruments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Interest Rate, Debt Instrument	8.25%
Carrying Value	$ 621,723,000	$ 689,911,000
Estimated fair value	664,325,000	719,600,000
Parent Company [Member]
Debt Instrument [Line Items]
Carrying Value	621,723,000	689,911,000
8.25% Notes [Member]
Debt Instrument [Line Items]
Interest Rate, Debt Instrument	8.25%
Face amount of 8.25% Notes	510,000,000
Carrying Value	496,723,000	494,911,000
Estimated fair value	539,325,000	524,600,000
Senior Credit Facility [Member]
Debt Instrument [Line Items]
Carrying Value	125,000,000	195,000,000
Estimated fair value	$ 125,000,000	$ 195,000,000