Voluntary Reorganization under Chapter 11 of the Bankruptcy Code - Additional Information (Details) - Payment in Kind (PIK) Note - 10% Senior Secured PIK Notes due 2021 - USD ($) $ in Millions	Sep. 27, 2016	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Stated interest rate		10.00%	10.00%
PIK Interest
Class of Stock [Line Items]
Stated interest rate		10.00%
Cash interest payment due		$ 14.2
September Exchange and Consent Solicitation | PIK Interest
Class of Stock [Line Items]
Stated interest rate	1.00%
Basis spread on variable rate	9.00%