Fair Value Measurements (Details)	Sep. 30, 2018	Dec. 31, 2017
7.75% senior notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	7.75%	7.75%
Trading prices rate to calculate the fair value		17.40%
Term loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading prices rate to calculate the fair value	98.81%	86.00%