Senior Debt (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Senior Debt (Table Details) [Abstract]
Unamortized Debt Issuance Expense	$ 4,100,000			$ 5,200,000
Mandatory Excess Cash Flow Pre-Payment	$ 6,000,000		$ 141,000,000
Commitment fee percentage	0.50%
Senior credit facilities, additional amount allowed	$ 100,000,000
Debt refinancing charges		$ 1,900,000
Debt arrangement and amendment fees		$ 5,300,000
Letters of credit, amount outstanding	$ 94,000,000
Financial Covenants Ratios (Table Details) [Abstract]
Required consolidated fixed charge coverage ratio, minimum	1.10
Actual consolidated fixed charge coverage ratio	0.22
Covenants [Abstract]
Adjusted consolidated EBITDA	$ 10,500,000
Consolidated fixed charges	$ 47,100,000
Event of default-3rd party ownership % of our voting stock	35.00%
Event of default-not satisfied or bonded judgment in excess of	$ 50,000,000
Maximum period allowed for pending judgment to satisfy or bond (in days)	30
Maturities of Long-term Debt [Abstract]
2018	$ 1,687,000
2019	22,250,000
2020	2,250,000
2021	35,513,000
2022	0
Thereafter	0
Total senior debt	$ 61,700,000
Minimum [Member]
Senior Debt (Table Details) [Abstract]
Commitment fee percentage	0.30%
Maximum [Member]
Senior Debt (Table Details) [Abstract]
Commitment fee percentage	0.50%
Prime Rate [Member]
Senior Debt (Table Details) [Abstract]
Description of variable rate basis	prime
Eurodollar [Member]
Senior Debt (Table Details) [Abstract]
Description of variable rate basis	Eurodollar rate
Term Loan [Member]
Debt Instrument [Line Items]
Senior Debt, Maximum Borrowing Capacity	$ 225,000,000
Senior Debt (Table Details) [Abstract]
Term loan, amount outstanding	$ 41,700,000			48,600,000
Maturity date	Mar. 19, 2021
Term Loan, Periodic Payment, Principal	$ 562,500
Maturities of Long-term Debt [Abstract]
2018	1,687,000
2019	2,250,000
2020	2,250,000
2021	35,513,000
2022	0
Thereafter	$ 0
Term Loan [Member] | Prime Rate [Member]
Senior Debt (Table Details) [Abstract]
Margin on Prime Rate, actual	2.00%
Term Loan [Member] | Eurodollar [Member]
Senior Debt (Table Details) [Abstract]
Margin on Eurodollar rate, actual	3.00%
Revolving Credit Facility [Member]
Senior Debt (Table Details) [Abstract]
Revolving facility, amount outstanding	$ 20,000,000			85,000,000
Maturity date	Mar. 19, 2019
Senior credit facility, maximum amount	$ 350,000,000
Covenants [Abstract]
Line of Credit Facility, Remaining Borrowing Capacity	172,800,000
Maturities of Long-term Debt [Abstract]
2018	0
2019	20,000,000
2020	0
2021	0
2022	0
Thereafter	$ 0
Revolving Credit Facility [Member] | Prime Rate [Member]
Senior Debt (Table Details) [Abstract]
Margin on Prime Rate, actual	2.00%
Revolving Credit Facility [Member] | Prime Rate [Member] | Minimum [Member]
Senior Debt (Table Details) [Abstract]
Basis margin on variable rate	0.50%
Revolving Credit Facility [Member] | Prime Rate [Member] | Maximum [Member]
Senior Debt (Table Details) [Abstract]
Basis margin on variable rate	2.00%
Revolving Credit Facility [Member] | Eurodollar [Member]
Senior Debt (Table Details) [Abstract]
Margin on Eurodollar rate, actual	3.00%
Revolving Credit Facility [Member] | Eurodollar [Member] | Minimum [Member]
Senior Debt (Table Details) [Abstract]
Basis margin on variable rate	1.50%
Revolving Credit Facility [Member] | Eurodollar [Member] | Maximum [Member]
Senior Debt (Table Details) [Abstract]
Basis margin on variable rate	3.00%
Line of Credit [Member]
Covenants [Abstract]
Unsecured line of credit, maximum facility	$ 12,500,000
Unsecured line of credit, amount outstanding	0			$ 5,700,000
Maturities of Long-term Debt [Abstract]
2018	0
2019	0
2020	0
2021	0
2022	0
Thereafter	$ 0