Income Taxes (Narrative) (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Income Taxes [Abstract] | ||||
| Effective tax rate | 34.00% | 34.00% | ||
| Blended federal and state effective tax rate | 37.50% | |||
| Percentage of estimated benefits from additional deductions | 3.50% | |||
| Income tax expense | $ 6,389 | $ 5,362 | $ 16,790 | $ 13,168 |
| Decrease in income tax expense from energy credits | $ 300 | |||