Revolving Credit Facilities, Term Loan, and the Notes (Details) (USD $)			0 Months Ended	3 Months Ended				1 Months Ended		3 Months Ended				0 Months Ended	1 Months Ended		3 Months Ended								3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 29, 2013 Credit agreement	Mar. 31, 2013 Credit agreement	Mar. 31, 2013 Senior secured super-priority revolving credit facility	Dec. 31, 2012 Senior secured super-priority revolving credit facility	Mar. 31, 2012 Senior secured super-priority revolving credit facility	Mar. 31, 2013 Senior secured term loan facility	Jul. 31, 2011 Senior secured term loan facility	Mar. 31, 2013 Senior secured term loan facility	Mar. 31, 2012 Senior secured term loan facility	Mar. 29, 2013 Senior secured term loan facility	Dec. 31, 2012 Senior secured term loan facility	Mar. 29, 2013 Senior secured term loan facility LIBOR	Mar. 31, 2013 Senior secured term loan facility LIBOR	Dec. 31, 2012 Senior secured term loan facility LIBOR	Mar. 31, 2013 Senior secured term loan facility Maximum	Mar. 31, 2013 Senior secured term loan facility Consolidated leverage ratio, equal to or less than 4.25 to 1 but greater than 3.25 to 1	Mar. 31, 2013 Senior secured term loan facility Consolidated leverage ratio, equal to or less than 4.25 to 1 but greater than 3.25 to 1 Maximum	Mar. 31, 2013 Senior secured term loan facility Consolidated leverage ratio, equal to or less than 4.25 to 1 but greater than 3.25 to 1 Minimum	Mar. 31, 2013 Senior secured term loan facility Consolidated leverage ratio, equal to or less than 3.25 to 1	Mar. 31, 2013 Senior secured term loan facility Consolidated leverage ratio, equal to or less than 3.25 to 1 Maximum	Mar. 31, 2013 Letter of Credit item	Dec. 31, 2012 Letter of Credit	Mar. 31, 2013 10.5% Senior Notes	Mar. 31, 2012 10.5% Senior Notes
Credit Facilities and Term Loan
Maximum borrowing capacity					$ 30,000,000
Costs incurred in connection with the amendment			1,800,000
Discount rate at issuance (as a percent)			0.25%
Discount at issuance			430,000
Debt issuance costs capitalized	11,209,000	10,421,000										1,100,000
Third-party debt issuance costs				260,000
Reduction in minimum base interest rate for LIBOR - based debt (as a percent)														4.00%		5.75%
Variable interest rate floor (as a percent)														1.00%
Variable applicable rate (as a percent)														3.00%
Reduction in LIBOR floor rate (as a percent)														0.25%
Reduction in applicable rate (as a percent)														1.50%
Basis of variable interest rate								LIBOR Rate		LIBOR Rate					LIBOR Rate
Quarterly principal payments required to be made									525,000	430,000
Additional principal payments required as a percentage of excess cash flow																	50.00%	25.00%			0.00%
Consolidated leverage ratio																			4.25	3.25		3.25
Additional principal payments required as a percentage of net cash proceeds of dispositions or casualty events, if not invested within one year										100.00%
Period of time within which proceeds must be reinvested										1 year
Additional principal payments required as a percentage of net cash proceeds from issuance of debt or Preferred Stock										100.00%
Outstanding borrowings					0
Outstanding balance under the Term Loan, net of unamortized discount								169,900,000		169,900,000			187,600,000
Principal payment on debt										17,400,000	18,000,000
Interest expense					0		0			2,900,000	3,300,000														8,100,000	8,000,000
Effective interest rate (as a percent)								6.40%		6.40%	6.30%														11.00%	11.00%
Weighted average nominal interest rate (as a percent)										5.82%	5.75%
Number of letters of credit outstanding																							1
Amount of letter of credit outstanding																							202,000	202,000
Commitment fees on unused revolving credit commitment (as a percent)					0.50%
Commitment fee expense					$ 38,000	$ 38,000