Goodwill and Intangible Assets (Amortization expense) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Amortization expense        
Amortization of intangible assets $ 1,238 $ 403 $ 2,172 $ 728