Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Stock-Based Compensation Expense (Details)

v3.10.0.1
Summary of Significant Accounting Policies - Stock-Based Compensation Expense (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Jan. 01, 2018
Dec. 31, 2017
Jan. 01, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Deferred income tax assets, net         $ 1,003    
Stock-based compensation expense $ 392 $ 307 $ 747 $ 650      
Stock Options              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Non-vested stock options unrecognized compensation expense $ 3,478   $ 3,478        
Non-vested stock options unrecognized compensation expense, weighted-average period of recognition     2 years 4 months 6 days        
Accounting Standards Update 2016-09              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Deferred income tax assets, net             $ 4,000
Retained Earnings | Accounting Standards Update 2016-09              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Credit to retained earnings           $ 4,000