Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity and Stock Based Compensation - Nonvested (Details)

v3.10.0.1
Stockholders' Equity and Stock Based Compensation - Nonvested (Details)
$ / shares in Units, $ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2018
USD ($)
$ / shares
shares
Jun. 30, 2018
USD ($)
installment
$ / shares
shares
Jun. 30, 2017
USD ($)
Dec. 31, 2017
installment
$ / shares
shares
General and Administrative Expense        
Weighted Average Grant Date Fair Value        
Share-based compensation cost | $   $ 2.4 $ 0.7  
Separation Expense | Former Chief Executive Officer        
Weighted Average Grant Date Fair Value        
Share-based compensation cost | $ $ 1.7 $ 1.7    
Restricted stock        
Shares        
Nonvested shares at the beginning of the period   161,818    
Granted (in shares)   95,500   87,076
Vested (in shares)   (154,960)    
Forfeited (in shares)       (22,694)
Nonvested shares at the end of the period 102,358 102,358   161,818
Weighted Average Grant Date Fair Value        
Nonvested shares at the beginning of period (in dollars per share) | $ / shares   $ 17.26    
Granted (in dollars per share) | $ / shares   15.60    
Vested (in dollars per share) | $ / shares   16.89    
Nonvested shares at the end of period (in dollars per share) | $ / shares $ 16.27 $ 16.27   $ 17.26
Unrecognized compensation cost (in dollars) | $ $ 1.6 $ 1.6    
Weighted average period for recognition of unrecognized compensation cost   2 years 2 months 12 days    
Restricted stock | Maximum        
Shares        
Number of equal quarterly installments for vesting of awards | installment   20   20
Restricted stock | Minimum        
Shares        
Number of equal quarterly installments for vesting of awards | installment   16   12