Fair Value Measurements (Details) - Level 1 - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
10.75% Senior Notes due 2023	$ 297,411	$ 297,269
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
10.75% Senior Notes due 2023	$ 245,568	$ 257,806