Long-term Debt (Details 2) (USD $)	6 Months Ended				1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended		1 Months Ended				1 Months Ended	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 RTS	Jun. 30, 2012 RTS	Apr. 30, 2010 Senior secured credit facility - (Term Loan B portion)	Dec. 31, 2012 Senior secured credit facility - (Term Loan B portion) RTS	Apr. 30, 2010 Senior secured credit facility (revolving credit portion)	Dec. 31, 2012 Senior secured credit facility (revolving credit portion) RTS	Apr. 30, 2010 13.5% Senior Subordinated Notes, due 2015	Apr. 20, 2010 13.5% Senior Subordinated Notes, due 2015	Apr. 30, 2010 9 7/8% Senior Subordinated Notes due April 15, 2017	Jun. 30, 2013 9 7/8% Senior Subordinated Notes due April 15, 2017	Dec. 31, 2012 9 7/8% Senior Subordinated Notes due April 15, 2017	Apr. 20, 2010 9 7/8% Senior Subordinated Notes due April 15, 2017	Mar. 31, 2011 9 7/8% Senior Subordinated Notes due April 15, 2017 RTS	Dec. 31, 2011 Lease line of credit	Aug. 31, 2011 Lease line of credit
Long-term debt
Issuance of long-term debt											$ 310,000,000				$ 50,000,000
Extinguishment of subordinated debt									175,000,000
Fixed interest rate (as a percent)										13.50%		9.875%	9.875%
Payment of call premium									5,300,000
Repayment of long-term debt	45,501,000	369,903,000	40,000,000	360,360,000	74,800,000	265,400,000	10,000,000	63,000,000
Expenses incurred associated with offering														11,900,000
Initial purchasers' discount	0	1,700,000									1,900,000
Proceeds from issuance of debt	83,880,000	434,061,000	82,500,000	433,345,000											48,500,000
Maximum borrowing capacity																	12,500,000
Current borrowing capacity																$ 8,700,000