Income Taxes - State Tax Rate (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Income Taxes | ||
| Texas state tax rate (as a percent) | 0.75% | 1.00% |
| Benefit from revaluing deferred tax assets at the newly enacted rate | $ 1.7 | |
| Benefit from revaluing deferred tax assets at the newly enacted rate, non-controlling interest | $ 1.0 | |