Fair Value Measurement Disclosures (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Carrying Amount | Significant other observable inputs (Level 2) | Twelve Point Five Percentage Senior Secured Notes Due Two Thousand Seventeen
Estimated fair values of financial instruments
12.5% senior secured notes due 2017	$ 275.0	$ 275.0
Carrying Amount | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
Promissory note payable, included in other long- term debt	5.1	5.2
Carrying Amount | Series B Preferred Stock | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
10 3/4% Series B cumulative exchangeable redeemable preferred stock	141.2	136.4
Fair Value | Significant other observable inputs (Level 2) | Twelve Point Five Percentage Senior Secured Notes Due Two Thousand Seventeen
Estimated fair values of financial instruments
12.5% senior secured notes due 2017	285.7	286.5
Fair Value | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
Promissory note payable, included in other long- term debt	4.5	4.5
Fair Value | Series B Preferred Stock | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
10 3/4% Series B cumulative exchangeable redeemable preferred stock	$ 63.3	$ 61.8