Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Details)

v3.8.0.1
Stock-Based Compensation (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Nov. 03, 2014
Awards        
Stock Based Compensation        
Number of awards outstanding (in shares)       0
2014 Plan        
Fair value assumptions        
Dividend rate 0.00% 0.00% 0.00%  
2014 Plan | Restricted Stock        
Stock Based Compensation        
Fair value of shares vested $ 116 $ 674 $ 5,800  
Number of awards outstanding unvested (in shares) 24,000      
Weighted average grant date fair value awards outstanding unvested (in dollars per share) $ 13.43      
2014 Plan | Minimum        
Stock Based Compensation        
Vesting period 1 year      
Term of awards 7 years      
2014 Plan | Minimum | Options        
Stock Based Compensation        
Term of awards 4 years 7 months 6 days 4 years 7 months 6 days 4 years 7 months 6 days  
Fair value assumptions        
Volatility rate 24.40% 24.40% 24.40%  
2014 Plan | Maximum        
Stock Based Compensation        
Vesting period 5 years      
Term of awards 10 years      
2014 Plan | Maximum | Options        
Stock Based Compensation        
Term of awards 5 years 3 months 18 days 5 years 3 months 18 days 5 years 3 months 18 days  
Fair value assumptions        
Volatility rate 28.20% 28.20% 28.20%  
LTIPs | Skyhook | PARs and PSUs | Significant other observable inputs (Level 2) | Other liabilities        
Stock Based Compensation        
Deferred compensation $ 1,200 $ 1,700