Stock-based Compensation - Summary of Restricted Stock Unit Awards Activity (Details) - 2012 Long-Term Incentive Plan - RSUs - $ / shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding unvested at beginning of period (in shares) 55,603 91,218 158,557
Granted (in shares) 48,323 35,752 45,914
Vested (in shares) (85,036) (50,695) (88,610)
Forfeited (in shares) (18,890) (20,672) (24,643)
Outstanding unvested at end of period (in shares) 0 55,603 91,218
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]      
Outstanding unvested at beginning of period (in dollars per share) $ 13.59 $ 11.75 $ 7.73
Granted (in dollars per share) 3.44 16.68 21.43
Vested (in dollars per share) 7.70 12.81 10.68
Forfeited (in dollars per share) 14.15 12.74 7.75
Outstanding unvested at end of period (in dollars per share) $ 0.00 $ 13.59 $ 11.75