Income Taxes	9 Months Ended
Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Comprehensive tax legislation, enacted through the Tax Cuts and Jobs Act (“TCJA”) on December 22, 2017, significantly modified U.S. corporate income tax law. Provisional amounts have been recorded in our financial statements based on the Company’s initial analysis of the TCJA. The Company may adjust these amounts in future periods if our interpretation of the TCJA changes or as additional guidance from the U.S. Treasury becomes available. We have elected to recognize the tax on Global Intangible Low Taxed Income (“GILTI”) as a period expense in the year the tax is incurred. The effective income tax rate was 20.4% and 21.9% for the three and nine months ended September 30, 2018, respectively, and 27.3% and 28.5% for the three and nine months ended September 30, 2017, respectively. The decrease in 2018 was primarily due to the reduction of the U.S. federal corporate tax rate as a result of the enactment of the TCJA. At the end of each interim period, we estimate the annual effective tax rate and apply that rate to our ordinary quarterly earnings. The tax expense or benefit related to significant unusual or infrequently occurring items that will be separately reported or reported net of their related tax effect, and are individually computed, is recognized in the interim period in which those items occur. In addition, the effect of changes in enacted tax laws or rates or tax status is recognized in the interim period in which the change occurs. The Company is continuously subject to tax examinations in various jurisdictions. As of September 30, 2018 and December 31, 2017, the total amount of federal, state and local, and foreign unrecognized tax benefits was $152 million and $212 million, respectively, exclusive of interest and penalties. We recognize accrued interest and penalties related to unrecognized tax benefits in interest expense and operating-related expense, respectively. As of September 30, 2018 and December 31, 2017, we had $32 million and $59 million, respectively, of accrued interest and penalties associated with unrecognized tax benefits. The reduction in uncertain tax positions and associated accrued interest relates primarily to settlements with various tax authorities. Based on the current status of income tax audits, we believe that the total amount of unrecognized tax benefits may decrease by approximately $40 million in the next twelve months as a result of the resolution of tax examinations.

Income Taxes

Comprehensive tax legislation, enacted through the Tax Cuts and Jobs Act (“TCJA”) on December 22, 2017, significantly modified U.S. corporate income tax law. Provisional amounts have been recorded in our financial statements based on the Company’s initial analysis of the TCJA. The Company may adjust these amounts in future periods if our interpretation of the TCJA changes or as additional guidance from the U.S. Treasury becomes available. We have elected to recognize the tax on Global Intangible Low Taxed Income (“GILTI”) as a period expense in the year the tax is incurred.

The effective income tax rate was 20.4% and 21.9% for the three and nine months ended September 30, 2018, respectively, and 27.3% and 28.5% for the three and nine months ended September 30, 2017, respectively. The decrease in 2018 was primarily due to the reduction of the U.S. federal corporate tax rate as a result of the enactment of the TCJA.

At the end of each interim period, we estimate the annual effective tax rate and apply that rate to our ordinary quarterly earnings. The tax expense or benefit related to significant unusual or infrequently occurring items that will be separately reported or reported net of their related tax effect, and are individually computed, is recognized in the interim period in which those items occur. In addition, the effect of changes in enacted tax laws or rates or tax status is recognized in the interim period in which the change occurs.

The Company is continuously subject to tax examinations in various jurisdictions. As of September 30, 2018 and December 31, 2017, the total amount of federal, state and local, and foreign unrecognized tax benefits was $152 million and $212 million, respectively, exclusive of interest and penalties. We recognize accrued interest and penalties related to unrecognized tax benefits in interest expense and operating-related expense, respectively. As of September 30, 2018 and December 31, 2017, we had $32 million and $59 million, respectively, of accrued interest and penalties associated with unrecognized tax benefits. The reduction in uncertain tax positions and associated accrued interest relates primarily to settlements with various tax authorities. Based on the current status of income tax audits, we believe that the total amount of unrecognized tax benefits may decrease by approximately $40 million in the next twelve months as a result of the resolution of tax examinations.