Goodwill (Changes in Goodwill) (Details) $ in Thousands |
6 Months Ended |
|---|---|
|
Jun. 30, 2015
USD ($)
| |
| Goodwill [Roll Forward] | |
| Goodwill at beginning of period | $ 257,442 |
| Increase in goodwill related to acquisitions | 3,849 |
| Goodwill at end of period | $ 261,291 |