Income Taxes	3 Months Ended
Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We manage our affairs so that we are centrally managed and controlled in the United Kingdom (“U.K.”) and therefore have our tax residency in the U.K. The provision for income taxes consists of provisions for the U.K. and international income taxes. We operate in an international environment with operations in various locations outside the U.K. Accordingly, the consolidated income tax rate is a composite rate reflecting the earnings in the various locations and the applicable rates. The effective income tax rate for the three months ended March 31, 2019 was 17.1%, compared to 20.5% for the three months ended March 31, 2018. We continue to actively pursue initiatives to reduce our effective tax rate. The tax rate in any quarter can be affected positively or negatively by adjustments that are required to be reported in the specific quarter of resolution. The liability for uncertain tax positions was $49.6 million and $51.4 million at March 31, 2019 and December 31, 2018, respectively. We record penalties and interest related to unrecognized tax benefits in Provision for income taxes and Net interest expense, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income, which is consistent with our past practices.

Income Taxes

We manage our affairs so that we are centrally managed and controlled in the United Kingdom (“U.K.”) and therefore have our tax residency in the U.K. The provision for income taxes consists of provisions for the U.K. and international income taxes. We operate in an international environment with operations in various locations outside the U.K. Accordingly, the consolidated income tax rate is a composite rate reflecting the earnings in the various locations and the applicable rates.

The effective income tax rate for the three months ended March 31, 2019 was 17.1%, compared to 20.5% for the three months ended March 31, 2018. We continue to actively pursue initiatives to reduce our effective tax rate. The tax rate in any quarter can be affected positively or negatively by adjustments that are required to be reported in the specific quarter of resolution.

The liability for uncertain tax positions was $49.6 million and $51.4 million at March 31, 2019 and December 31, 2018, respectively. We record penalties and interest related to unrecognized tax benefits in Provision for income taxes and Net interest expense, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income, which is consistent with our past practices.