Stock-Based Compensation - Performance Stock Units Outstanding Activity (Details) - Performance Shares - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Awards      
Unvested beginning balance (in shares) 386,459    
Granted (in shares) 486,213    
Vested (in shares) 0    
Forfeited (in shares) 0    
Unvested ending balance (in shares) 872,672 386,459  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]      
Outstanding, beginning of period (in dollars per share) $ 21.94    
Granted (in dollars per share) 6.68 $ 22.35 $ 21.53
Vested (in dollars per share) 0    
Forfeited 0    
Outstanding, end of period (in dollars per share) $ 13.44 $ 21.94