Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
|
| Fair Value Disclosures [Abstract] | ||||
| Fair value, level 1 to level 2 transfers, amount | $ 0 | $ 0 | $ 0 | $ 0 |
| Fair value, level 2 to level 1 transfers, amount | 0 | 0 | 0 | 0 |
| Assets measured at fair value on a nonrecurring basis | 0 | 0 | 0 | 0 |
| Liabilities measured at fair value on a nonrecurring basis | $ 0 | $ 0 | $ 0 | $ 0 |