Recent Accounting Pronouncements (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2018
Jan. 01, 2018
Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Retained earnings $ 104,783   $ 91,242
Effective income tax rate reconciliation, change in enacted tax rate, amount 8,900    
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Retained earnings   $ 1,100  
Revenues $ 3,300