Share Repurchases (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
May 31, 2015
Number of common stock repurchased (in shares) 427,646 1,154,480  
Value of common stock repurchased $ 3,242 $ 9,020  
Maximum      
Common stock authorized for repurchase $ 7,700   $ 20,000