Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation (Schedule of Unvested Restricted Stock Units Activity) (Details)

v3.10.0.1
Share-Based Compensation (Schedule of Unvested Restricted Stock Units Activity) (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
RSU equity awards      
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]      
Outstanding at the beginning of the period (in shares) 1,790,000    
Granted (in shares) 872,000 1,173,094 684,090
Vested (in shares) (506,000)    
Forfeited (in shares) (53,000)    
Outstanding at the end of the period (in shares) 2,103,000 1,790,000  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Outstanding at the beginning of the period, Grant Date Fair Value per Share (usd per share) $ 11.54    
Granted, grant date fair value per share (usd per share) 13.89 $ 12.25 $ 12.63
Vested, grant date fair value per share (usd per share) 9.56    
Forfeited, grant date fair value per share (usd per share) 11.43    
Outstanding at the end of the period, grant date fair value per share (usd per share) $ 13.24 $ 11.54  
Weighted average period over which expense is expected to be recognized 1 year 10 months 6 days    
Fair value of shares vested $ 6,344 $ 9,045 $ 2,608
RSU equity awards | Vesting range 0 to 200%      
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]      
Outstanding at the end of the period (in shares) 208,000    
RSU equity awards | Vesting Minimum      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Share-based compensation arrangement vesting rights, percentage 0.00%    
RSU equity awards | Vesting Maximum      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Share-based compensation arrangement vesting rights, percentage 200.00%    
Market-based Cash-settleable RSUs Awards      
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]      
Vested (in shares) (207,261) (335,471)  
Market-based RSUs | Vesting Minimum      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Share-based compensation arrangement vesting rights, percentage 0.00%    
Market-based RSUs | Vesting Maximum      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Share-based compensation arrangement vesting rights, percentage 200.00%