Stock-based Compensation - Performance Unit Awards - Monte Carlo Simulation (Details) - Performance Unit Awards - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Assumptions used to determine the grant date fair value and associated compensation expense
Stock Price (in dollars per share)	$ 10.11	$ 17.07
Beginning Average Stock Price (in dollars per share)	$ 11.56	$ 14.78
Expected Volatility (as a percent)	55.13%	46.95%
Risk-Free Rate of Return (as a percent)	0.79%	0.61%
Number of trading days (in days)	10 days
Remaining in the performance period (in years)	2 years 8 months 1 day	2 years 7 months 13 days
Expected percentage of performance units earned (as a percent)	101.61%	126.80%