Income Taxes	6 Months Ended
Jun. 30, 2017
Income Taxes [Abstract]
Income Taxes	(8)Income Taxes Our effective tax rate (ETR) for 2017 was estimated at 11% and 15% for the six months ended June 30, 2017 and 2016, respectively. Assuming no changes in our expected results of operations, we expect our ETR for the remainder of 2017 to be about the same as the first six months of 2017. Our ETR differs from the statutory rate due primarily to statutory depletion in excess of tax basis, which is a permanent difference.

Income Taxes

6 Months Ended

Jun. 30, 2017

(8)Income Taxes

Our effective tax rate (ETR) for 2017 was estimated at 11% and 15% for the six months ended June 30, 2017 and 2016, respectively. Assuming no changes in our expected results of operations, we expect our ETR for the remainder of 2017 to be about the same as the first six months of 2017. Our ETR differs from the statutory rate due primarily to statutory depletion in excess of tax basis, which is a permanent difference.