XML 27 R14.htm IDEA: XBRL DOCUMENT v3.7.0.1
Income Taxes
3 Months Ended
Mar. 31, 2017
Income Taxes [Abstract]  
Income Taxes

(8)Income Taxes



Our effective tax rate (ETR) for 2017 was estimated at 8% and 22% as of March 31, 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 quarter of 2017.  Our ETR differs from the statutory rate due primarily to statutory depletion in excess of tax basis, which is a permanent difference.