Fair value of Financial Instruments (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
8 7/8% Senior Secured Second Lien Notes due January 15, 2017
Financial instruments
Interest rate (as a percent)	8.875%	8.875%
Face amount	$ 350,000,000	$ 350,000,000
Fair Value	328,125,000	344,750,000
Carrying Value	348,752,000	348,577,000
9 7/8% Senior Subordinated Notes due April 15, 2017
Financial instruments
Interest rate (as a percent)	9.875%	9.875%
Face amount	376,300,000	376,300,000
Fair Value	235,156,000	265,256,000
Carrying Value	$ 374,667,000	$ 374,461,000