Income Taxes	3 Months Ended
Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For interim income tax reporting we estimate our annual effective tax rate and apply it to our year to date ordinary income (loss). Tax jurisdictions with a projected or year to date loss for which a tax benefit cannot be realized are excluded. The tax effects of unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, are reported in the interim period in which they occur. In the three months ended March 31, 2019 Income tax expense of $137 million primarily resulted from tax expense attributable to entities included in our effective tax rate calculation, partially offset by tax benefits related to a release of valuation allowance and benefits from foreign dividends. The effective tax rate is lower than the applicable statutory tax rate due primarily to tax benefits related to a release of valuation allowance and benefits from foreign dividends. In the three months ended March 31, 2018 Income tax expense of $466 million primarily resulted from tax expense attributable to entities included in our effective tax rate calculation. The recorded effective tax rate is higher than the applicable statutory tax rate due primarily to losses incurred in jurisdictions for which a valuation allowance is recorded. At March 31, 2019 we had $23.6 billion of net deferred tax assets consisting of net operating losses and income tax credits, capitalized research expenditures and other timing differences that are available to offset future income tax liabilities, partially offset by valuation allowances.

Income Taxes

For interim income tax reporting we estimate our annual effective tax rate and apply it to our year to date ordinary income (loss). Tax jurisdictions with a projected or year to date loss for which a tax benefit cannot be realized are excluded. The tax effects of unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, are reported in the interim period in which they occur.

In the three months ended March 31, 2019 Income tax expense of $137 million primarily resulted from tax expense attributable to entities included in our effective tax rate calculation, partially offset by tax benefits related to a release of valuation allowance and benefits from foreign dividends. The effective tax rate is lower than the applicable statutory tax rate due primarily to tax benefits related to a release of valuation allowance and benefits from foreign dividends.

In the three months ended March 31, 2018 Income tax expense of $466 million primarily resulted from tax expense attributable to entities included in our effective tax rate calculation. The recorded effective tax rate is higher than the applicable statutory tax rate due primarily to losses incurred in jurisdictions for which a valuation allowance is recorded.

At March 31, 2019 we had $23.6 billion of net deferred tax assets consisting of net operating losses and income tax credits, capitalized research expenditures and other timing differences that are available to offset future income tax liabilities, partially offset by valuation allowances.