Long-term Debt - Pro Forma Impact of Bond Exchange Program (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Apr. 28, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Aggregate principal amount of debt	$ 165,501		$ 182,992
Senior secured second-priority notes (maturing December 15, 2021) [Member] | Senior notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount of debt	120,569	$ 120,600	0
Senior secured third-priority notes (maturing May 15, 2018) [Member] | Senior notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount of debt	$ 28,497	$ 28,500	$ 175,000