Fair Value Measurements (Schedule of Carrying Values and Estimated Fair Values of Debt Instruments) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Carrying Value	$ 627,355,000	$ 689,911,000
Estimated fair value	676,338,000	719,600,000
Parent Company [Member]
Debt Instrument [Line Items]
Carrying Value	627,355,000	689,911,000
8.25% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Notes, stated percentage	8.25%
Face amount of 8.25% Notes	510,000,000
Carrying Value	497,355,000	494,911,000
Estimated fair value	546,338,000	524,600,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Carrying Value	130,000,000	195,000,000
Estimated fair value	$ 130,000,000	$ 195,000,000