Fair Value Measurement Disclosures - Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Carrying Amount | Significant other observable inputs (Level 2) | 12.5% Senior Secured Notes Due 2017
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	4.6	4.9
Fair Value | Significant other observable inputs (Level 2) | 12.5% Senior Secured Notes Due 2017
Estimated fair values of financial instruments
12.5% senior secured notes due 2017	275.5	281.2
Fair Value | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
Promissory note payable, included in other long- term debt	4.7	4.2
Series B Preferred Stock | Carrying Amount | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
10 3/4% Series B cumulative exchangeable redeemable preferred stock	155.8	146.1
Series B Preferred Stock | Fair Value | Significant unobservable inputs (Level 3)
Estimated fair values of financial instruments
10 3/4% Series B cumulative exchangeable redeemable preferred stock	$ 60.5	$ 60.1