Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Commitments and Contingencies [Abstract] | ||
| Line of credit facility, commitment amount | $ 73,500 | $ 36,300 |
| Letters of credit outstanding, amount | 21,400 | 16,900 |
| Amounts available under lines of credit | $ 128,800 | $ 114,700 |