Income Taxes	3 Months Ended
Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our effective tax rate was 38 percent in first quarter 2016, which includes a three percent benefit for a partial release of our valuation allowance and a five percent detriment for goodwill due to the sale of oil and gas assets. Our effective tax rate was 35 percent in first quarter 2015, which included a two percent benefit for noncontrolling interests and a two percent detriment for share-based compensation benefits that will not be realized. Our effective tax rates also include the effect of state income taxes, nondeductible items and benefits of percentage depletion. At first quarter-end 2016 and year-end 2015, we have a valuation allowance for our deferred tax assets of $95,389,000 and $97,068,000 for the portion of the deferred tax assets that we have determined is more likely than not to be unrealizable. In determining our valuation allowance, we assessed available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax asset. A significant piece of objective evidence evaluated was the cumulative loss incurred over the three-year period ended March 31, 2016, principally driven by impairments of oil and gas properties in 2015. Such evidence limits our ability to consider other subjective evidence, such as our projected future taxable income. The amount of the deferred tax asset considered realizable could be adjusted if negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence, such as our projected future taxable income.

Income Taxes

3 Months Ended

Mar. 31, 2016

Our effective tax rate was 38 percent in first quarter 2016, which includes a three percent benefit for a partial release of our valuation allowance and a five percent detriment for goodwill due to the sale of oil and gas assets. Our effective tax rate was 35 percent in first quarter 2015, which included a two percent benefit for noncontrolling interests and a two percent detriment for share-based compensation benefits that will not be realized. Our effective tax rates also include the effect of state income taxes, nondeductible items and benefits of percentage depletion.

At first quarter-end 2016 and year-end 2015, we have a valuation allowance for our deferred tax assets of $95,389,000 and $97,068,000 for the portion of the deferred tax assets that we have determined is more likely than not to be unrealizable.

In determining our valuation allowance, we assessed available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax asset. A significant piece of objective evidence evaluated was the cumulative loss incurred over the three-year period ended March 31, 2016, principally driven by impairments of oil and gas properties in 2015. Such evidence limits our ability to consider other subjective evidence, such as our projected future taxable income.

The amount of the deferred tax asset considered realizable could be adjusted if negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence, such as our projected future taxable income.