Long Term Debt (Details Textual) (USD $)	1 Months Ended	9 Months Ended							12 Months Ended				12 Months Ended		12 Months Ended						0 Months Ended								0 Months Ended
	Feb. 14, 2013	Sep. 30, 2014	Dec. 31, 2013	Feb. 14, 2013 Senior Secured Notes due 2019	Feb. 14, 2013 Revolving Credit Facility Letter of Credit	Feb. 14, 2013 Revolving Credit Facility Line of Credit covenants	Feb. 14, 2013 Term Loan, due 2019 Notes Payable to Banks	Jan. 24, 2011 Term Loan, due 2019 Term Loan under the Credit Agreement	Dec. 31, 2012 Condition One	Dec. 31, 2012 Condition One Term Loan under the Credit Agreement	Dec. 31, 2012 Condition Two, Subcondition One	Dec. 31, 2013 Condition Two, Subcondition Two	Dec. 31, 2012 Condition Two, Subcondition Three	Feb. 14, 2013 Senior Secured Notes Due 2019	Dec. 31, 2012 Line of Credit	Dec. 31, 2012 Line of Credit Years 1-3	Feb. 14, 2013 Maximum Revolving Credit Facility Line of Credit	Feb. 14, 2013 Maximum Term Loan, due 2019 Notes Payable to Banks	Feb. 14, 2013 Minimum Revolving Credit Facility Line of Credit	Feb. 14, 2013 Minimum Term Loan, due 2019 Notes Payable to Banks	Feb. 14, 2013 Federal Funds Effective Rate	Feb. 14, 2013 London Interbank Offered Rate (LIBOR)	Feb. 14, 2013 London Interbank Offered Rate (LIBOR) Senior Secured Notes Due 2019 Term Loan, due 2019	Feb. 14, 2013 Commitment Fee, Period One Revolving Credit Facility Line of Credit	Feb. 14, 2013 Commitment Fee, Period Two Revolving Credit Facility Line of Credit	Feb. 14, 2013 Debt Instrument, Redemption, Period Six Senior Secured Notes Due 2019 Term Loan, due 2019 Notes Payable to Banks	Feb. 14, 2013 Mandatory Repayments, Period One Senior Secured Notes Due 2019 Term Loan, due 2019 Notes Payable to Banks	Feb. 14, 2013 Mandatory Repayments, Subsequent Periods Senior Secured Notes Due 2019 Term Loan, due 2019 Notes Payable to Banks	Feb. 14, 2013 Debt Instrument, Redemption, Period Five Senior Secured Notes Due 2019 Term Loan, due 2019 Notes Payable to Banks	Feb. 14, 2013 Debt Instrument, Redemption, Period One Senior Secured Notes Due 2019	Feb. 15, 2013 Debt Instrument, Redemption, Period One Senior Secured Notes Due 2019	Jan. 24, 2011 Bank of America Syndicate Revolving Credit Facility Senior Secured Credit Facility	Jan. 24, 2011 Bank of America Syndicate Line of Credit Senior Secured Credit Facility
Long Term Debt (Textual) [Abstract]
Remaining borrowing capacity		$ 58,800,000
Letter of credit outstanding		16,200,000
Refinancing [Abstract]
Debt Instrument, Face Amount				300,000,000.0				1,000,000,000.0						300,000,000.0
Stated interest rate				8.75%										8.75%			5.50%	6.25%	4.50%	5.25%
Line of of credit facility oustanding					40,000,000.0	75,000,000.0
Long-term debt		915,448,000	918,122,000				640,000,000.0
Repayments of Debt	946,500,000
Maximum borrowing capacity																		200,000,000.0														75,000,000.0	1,075,000,000.0
Loan origination fees of Revolving Facility for future years																1,500,000
Minimum floor interest rate on Term Loan under condition one										2.00%
Interest rate in addition to Libor under subcondition two of condition two												0.50%
Base interest rate under condition		LIBOR							LIBOR		Bank of America's prime rate		LIBOR
Point in addition to base interest rate under condition									4.50%		3.50%		1.00%								0.50%	1.00%	1.25%
Debt Instrument, Fronting Fee, Percentage																			0.125%
Percentage commitment fee on average daily unused portion of exit revolving facility															0.75%									0.50%	0.375%
Debt Instrument, Periodic Payment, Principal																										$ 1,600,000
Debt Instrument, Mandatory Repayments, Percentage of Excess Cash Flow																											50.00%	25.00%
Debt Instrument, Redemption Price, Percentage																										101.00%			102.00%	108.75%
Debt Instruments, Retrictive Covenants, Number						2
Line of Credit Facility, Covenant Terms, Interest Coverage Ratio, Minimum		2.00
Line of Credit Facility, Covenant Terms, Future Interest Coverage Ratio, Minimum		2.25
Line of Credit Facility, Covenant Terms, Leverage Ratio, Maximum		5.50
Line of Credit Facility, Covenant Terms, Leverage Ratio, Maximum, Periodic Decrease		0.25
Debt Instrument, Default Redemption, Percent of Principal																															100.00%
Debt Instrument, Principal, Redemption Percentage, Maximum																															35.00%