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Supplemental Guarantor Information - Additional Information (Details) - Senior Notes
Sep. 30, 2017
Mar. 31, 2017
Jan. 31, 2017
10.5% Senior Notes      
Debt Instrument [Line Items]      
Debt instrument interest rate 10.50%    
7.0% Senior Notes      
Debt Instrument [Line Items]      
Debt instrument interest rate   7.00% 7.00%