Income Taxes	6 Months Ended
Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective income tax rate was 28.6% and 29.1% for the three and six months ended June 30, 2017, respectively, and 32.3% and 31.9% for the three and six months ended June 30, 2016, respectively. The decrease in 2017 was primarily due to the recognition of excess tax benefits associated with share-based payments in the statement of income, the resolution of tax audits and a benefit from an acquisition-related adjustment. 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 or unusual 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 June 30, 2017 and December 31, 2016, the total amount of federal, state and local, and foreign unrecognized tax benefits was $139 million and $161 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. In addition, as of June 30, 2017 and December 31, 2016, we had $49 million and $44 million, respectively, of accrued interest and penalties associated with unrecognized tax benefits. Based on the current status of income tax audits, we believe that the total amount of unrecognized tax benefits on the balance sheet may be reduced by up to approximately $32 million in the next twelve months as a result of the resolution of local tax examinations. In November of 2015, the Financial Accounting Standards Board ("FASB") issued guidance to simplify the presentation of deferred income taxes. The guidance requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This guidance is effective for reporting periods beginning after December 15, 2016; however, early adoption was permitted. We early adopted this guidance in the fourth quarter of 2016, prospectively, and accordingly prior year amounts have not been reclassified.

Income Taxes

The effective income tax rate was 28.6% and 29.1% for the three and six months ended June 30, 2017, respectively, and 32.3% and 31.9% for the three and six months ended June 30, 2016, respectively. The decrease in 2017 was primarily due to the recognition of excess tax benefits associated with share-based payments in the statement of income, the resolution of tax audits and a benefit from an acquisition-related adjustment.

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 or unusual 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 June 30, 2017 and December 31, 2016, the total amount of federal, state and local, and foreign unrecognized tax benefits was $139 million and $161 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. In addition, as of June 30, 2017 and December 31, 2016, we had $49 million and $44 million, respectively, of accrued interest and penalties associated with unrecognized tax benefits. Based on the current status of income tax audits, we believe that the total amount of unrecognized tax benefits on the balance sheet may be reduced by up to approximately $32 million in the next twelve months as a result of the resolution of local tax examinations.

In November of 2015, the Financial Accounting Standards Board ("FASB") issued guidance to simplify the presentation of deferred income taxes. The guidance requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This guidance is effective for reporting periods beginning after December 15, 2016; however, early adoption was permitted. We early adopted this guidance in the fourth quarter of 2016, prospectively, and accordingly prior year amounts have not been reclassified.