Income Taxes	6 Months Ended
Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three months ended June 30, 2017, we reported an effective tax rate of 27.0%, which was lower than the 35% U.S. federal statutory rate due primarily to the impact of excess tax benefits related to the adoption of ASU No. 2016-09. Effective January 1, 2017, this new guidance requires any excess tax benefits for share-based payment award transactions to be recorded in the income statement. Accordingly, we recognized excess tax benefits on stock option exercises, which resulted in a decrease in tax expense of $11.4 million. For the six months ended June 30, 2017, we reported an effective tax rate of 21.6%, which was lower than 35% U.S. federal statutory rate due primarily to the excess tax benefits on stock option exercises of $23.0 million, and the first quarter 2017 ownership structure change for certain international subsidiaries which resulted in a decrease in income tax expense of $4.3 million. For the three months ended June 30, 2016, we reported an effective tax rate of 45.3%, which was higher than the 35% U.S. federal statutory rate due primarily to the tax expense on unremitted foreign earnings not considered permanently reinvested, the impact of valuation allowances on the losses of certain foreign subsidiaries, and changes in state tax rates. For the six months ended June 30, 2016, we reported an effective tax rate of 45.2%, which was higher than 35% U.S. federal statutory rate due primarily to the tax expense on unremitted foreign earnings not considered permanently reinvested and the impact of valuation allowances on the losses of certain foreign subsidiaries. The total amount of unrecognized tax benefits was $5.9 million as of June 30, 2017, and $4.8 million as of December 31, 2016. These same amounts would affect the effective tax rate, if recognized. The accrued interest payable for taxes was insignificant as of June 30, 2017 and December 31, 2016. There was no significant liability for tax penalties as of June 30, 2017 or December 31, 2016. We are regularly audited by federal, state and foreign taxing authorities. Given the uncertainties inherent in the audit process, it is reasonably possible that certain audits could result in a significant increase or decrease in the total amounts of unrecognized tax benefits. An estimate of the range of the increase or decrease in unrecognized tax benefits due to audit results cannot be made at this time. Tax years 2008 and forward remain open for examination in some state and foreign jurisdictions, and tax years 2012 and forward remain open for examination for U.S. federal purposes.

Income Taxes

For the three months ended June 30, 2017, we reported an effective tax rate of 27.0%, which was lower than the 35% U.S. federal statutory rate due primarily to the impact of excess tax benefits related to the adoption of ASU No. 2016-09. Effective January 1, 2017, this new guidance requires any excess tax benefits for share-based payment award transactions to be recorded in the income statement. Accordingly, we recognized excess tax benefits on stock option exercises, which resulted in a decrease in tax expense of $11.4 million. For the six months ended June 30, 2017, we reported an effective tax rate of 21.6%, which was lower than 35% U.S. federal statutory rate due primarily to the excess tax benefits on stock option exercises of $23.0 million, and the first quarter 2017 ownership structure change for certain international subsidiaries which resulted in a decrease in income tax expense of $4.3 million.

For the three months ended June 30, 2016, we reported an effective tax rate of 45.3%, which was higher than the 35% U.S. federal statutory rate due primarily to the tax expense on unremitted foreign earnings not considered permanently reinvested, the impact of valuation allowances on the losses of certain foreign subsidiaries, and changes in state tax rates. For the six months ended June 30, 2016, we reported an effective tax rate of 45.2%, which was higher than 35% U.S. federal statutory rate due primarily to the tax expense on unremitted foreign earnings not considered permanently reinvested and the impact of valuation allowances on the losses of certain foreign subsidiaries.

The total amount of unrecognized tax benefits was $5.9 million as of June 30, 2017, and $4.8 million as of December 31, 2016. These same amounts would affect the effective tax rate, if recognized. The accrued interest payable for taxes was insignificant as of June 30, 2017 and December 31, 2016. There was no significant liability for tax penalties as of June 30, 2017 or December 31, 2016. We are regularly audited by federal, state and foreign taxing authorities. Given the uncertainties inherent in the audit process, it is reasonably possible that certain audits could result in a significant increase or decrease in the total amounts of unrecognized tax benefits. An estimate of the range of the increase or decrease in unrecognized tax benefits due to audit results cannot be made at this time. Tax years 2008 and forward remain open for examination in some state and foreign jurisdictions, and tax years 2012 and forward remain open for examination for U.S. federal purposes.