Guarantor Non-Guarantor Subsidiary Financial Information Level 4 (Details) - Additional Information	Sep. 30, 2018	Dec. 31, 2017
6.625% First Priority Senior Notes Due 2020 [Member]
Guarantor Obligations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%	6.625%
10.00% First Priority Senior Notes Due 2020 [Member]
Guarantor Obligations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	10.00%	10.00%
10.375% First-Priority Senion Secured Notes due 2022 [Member]
Guarantor Obligations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	10.375%	10.375%
13.75% Senior Secured Notes due 2022 [Member]
Guarantor Obligations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	13.75%	13.75%
9.00% Second-Priority Senior Secured Notes Due 2020 [Member]
Guarantor Obligations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.00%	9.00%