Income Taxes	6 Months Ended
Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We estimate our annual effective tax rate based on year-to-date operating results and our forecast for the remainder of the year, by jurisdiction, and apply this rate to the year-to-date operating results. If our actual results, by jurisdiction, differ from the forecasted operating results, our effective tax rate can change, affecting the tax expense for both successive interim results as well as the annual tax results. For the second quarter and the first six months of 2016, we had a tax benefit of $102 million and $203 million, respectively, on a loss before income taxes of $664 million and $1.26 billion, respectively. Our results for the second quarter of 2016 include charges with no significant tax benefit principally related to $75 million of settlement charges, $78 million of bond tender premium, and $84 million of PDVSA note adjustment, partially offset by $52 million of Zubair project gains with no significant tax expense. Our results for the first six months of 2016 include charges with no significant tax benefit principally related to $140 million of settlement charges, $31 million of currency devaluation related to the Angolan kwanza, $78 million of bond tender premium, and $84 million of PDVSA note adjustment. We are continuously under tax examination in various jurisdictions. We cannot predict the timing or outcome regarding resolution of these tax examinations or if they will have a material impact on our financial statements. We continue to anticipate a possible reduction in the balance of uncertain tax positions of approximately $42 million in the next twelve months due to expiration of statutes of limitations, settlements and/or conclusions of tax examinations. For both the second quarter and the first six months of 2015, we had a $132 million tax benefit on a loss before income taxes of $615 million and $722 million, respectively. Our results for the second quarter of 2015 includes $112 million of litigation settlements, $69 million of project losses, $16 million of devaluation of the Angolan kwanza currency, $20 million of equity investment impairment and $69 million of restructuring charges, with no significant tax benefit. Our results for the first six months of 2015 includes $112 million of litigation settlements, $27 million of project losses, $42 million of currency devaluation, $20 million of equity investment impairment and $110 million of restructuring charges, with no significant tax benefit.

Income Taxes

We estimate our annual effective tax rate based on year-to-date operating results and our forecast for the remainder of the year, by jurisdiction, and apply this rate to the year-to-date operating results. If our actual results, by jurisdiction, differ from the forecasted operating results, our effective tax rate can change, affecting the tax expense for both successive interim results as well as the annual tax results. For the second quarter and the first six months of 2016, we had a tax benefit of $102 million and $203 million, respectively, on a loss before income taxes of $664 million and $1.26 billion, respectively. Our results for the second quarter of 2016 include charges with no significant tax benefit principally related to $75 million of settlement charges, $78 million of bond tender premium, and $84 million of PDVSA note adjustment, partially offset by $52 million of Zubair project gains with no significant tax expense. Our results for the first six months of 2016 include charges with no significant tax benefit principally related to $140 million of settlement charges, $31 million of currency devaluation related to the Angolan kwanza, $78 million of bond tender premium, and $84 million of PDVSA note adjustment.

We are continuously under tax examination in various jurisdictions. We cannot predict the timing or outcome regarding resolution of these tax examinations or if they will have a material impact on our financial statements. We continue to anticipate a possible reduction in the balance of uncertain tax positions of approximately $42 million in the next twelve months due to expiration of statutes of limitations, settlements and/or conclusions of tax examinations.

For both the second quarter and the first six months of 2015, we had a $132 million tax benefit on a loss before income taxes of $615 million and $722 million, respectively. Our results for the second quarter of 2015 includes $112 million of litigation settlements, $69 million of project losses, $16 million of devaluation of the Angolan kwanza currency, $20 million of equity investment impairment and $69 million of restructuring charges, with no significant tax benefit. Our results for the first six months of 2015 includes $112 million of litigation settlements, $27 million of project losses, $42 million of currency devaluation, $20 million of equity investment impairment and $110 million of restructuring charges, with no significant tax benefit.