Principles of Consolidation and Other Matters	9 Months Ended
Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation and Other Matters	Principles of Consolidation and Other Matters The consolidated financial statements included herein have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission. While certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations for interim filings, the Company believes that the information and disclosures presented are adequate to make such information and disclosures not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the "2016 Form 10-K"). The financial information contained herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the Company’s consolidated financial statements as of and for the three and nine month periods ended September 30, 2017 and 2016. Cash and Cash Equivalents Cash and cash equivalents primarily consist of certificates of deposit and time deposits, with original maturities of three months or less, and money market funds. The estimated fair value of the Company's cash and cash equivalents approximates their carrying value. The Company is required to maintain operating funds of approximately $184 million, primarily related to regulatory requirements outside the United States or as collateral under captive insurance arrangements. Investments The Company holds investments in certain private equity funds. Investments in private equity funds are accounted for under the equity method of accounting using a consistently applied three-month lag period adjusted for any known significant changes from the lag period to the reporting date of the Company. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. Investment gains or losses for the Company's proportionate share of the change in fair value of the funds are recorded in earnings. Investments accounted for using the equity method of accounting are included in other assets in the consolidated balance sheets. The caption "Investment income (loss)" in the consolidated statements of income comprises realized and unrealized gains and losses from investments recognized in earnings. It includes, when applicable, other than temporary declines in the value of debt and available-for-sale securities and equity method gains or losses on the Company's investments in private equity funds. The Company recorded a net investment loss of $2 million in the third quarter of 2017 compared to a net investment gain of less than $1 million for the same period in 2016, and net investment income of $3 million compared to a net investment loss of $2 million for the nine months ended September 30, 2017 and 2016, respectively. Income Taxes The Company's effective tax rate in the third quarter of 2017 was 26.2% compared with 26.8% in the third quarter of 2016. The effective tax rate for the first nine months of 2017 and 2016 was 25.9% and 28.4%, respectively. The rates reflect foreign operations which are taxed at rates below the U.S. statutory tax rate, including the effect of repatriation, as well as the impact of discrete tax matters such as tax legislation, changes in valuation allowances, nontaxable adjustments to contingent acquisition consideration and, starting in 2017, excess tax benefits related to share-based compensation. The Company is routinely examined by tax authorities in the jurisdictions in which it has significant operations. The Company regularly considers the likelihood of assessments in each of the taxing jurisdictions resulting from examinations. When evaluating the potential imposition of penalties, the Company considers a number of relevant factors under penalty statutes, including appropriate disclosure of the tax return position, the existence of legal authority supporting the Company's position, and reliance on the opinion of professional tax advisors. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in tax returns. The Company's gross unrecognized tax benefits decreased from $65 million at December 31, 2016 to $64 million at September 30, 2017 due to settlements of audits and expirations of statutes of limitation, partially offset by current accruals. It is reasonably possible that the total amount of unrecognized tax benefits will decrease between zero and approximately $9 million within the next twelve months due to settlements of audits and expirations of statutes of limitation.

Principles of Consolidation and Other Matters

The consolidated financial statements included herein have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission. While certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations for interim filings, the Company believes that the information and disclosures presented are adequate to make such information and disclosures not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (the "2016 Form 10-K").

The financial information contained herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the Company’s consolidated financial statements as of and for the three and nine month periods ended September 30, 2017 and 2016.

Cash and Cash Equivalents

Cash and cash equivalents primarily consist of certificates of deposit and time deposits, with original maturities of three months or less, and money market funds. The estimated fair value of the Company's cash and cash equivalents approximates their carrying value. The Company is required to maintain operating funds of approximately $184 million, primarily related to regulatory requirements outside the United States or as collateral under captive insurance arrangements.

Investments

The Company holds investments in certain private equity funds. Investments in private equity funds are accounted for under the equity method of accounting using a consistently applied three-month lag period adjusted for any known significant changes from the lag period to the reporting date of the Company. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. Investment gains or losses for the Company's proportionate share of the change in fair value of the funds are recorded in earnings. Investments accounted for using the equity method of accounting are included in other assets in the consolidated balance sheets.

The caption "Investment income (loss)" in the consolidated statements of income comprises realized and unrealized gains and losses from investments recognized in earnings. It includes, when applicable, other than temporary declines in the value of debt and available-for-sale securities and equity method gains or losses on the Company's investments in private equity funds. The Company recorded a net investment loss of $2 million in the third quarter of 2017 compared to a net investment gain of less than $1 million for the same period in 2016, and net investment income of $3 million compared to a net investment loss of $2 million for the nine months ended September 30, 2017 and 2016, respectively.

Income Taxes

The Company's effective tax rate in the third quarter of 2017 was 26.2% compared with 26.8% in the third quarter of 2016. The effective tax rate for the first nine months of 2017 and 2016 was 25.9% and 28.4%, respectively. The rates reflect foreign operations which are taxed at rates below the U.S. statutory tax rate, including the effect of repatriation, as well as the impact of discrete tax matters such as tax legislation, changes in valuation allowances, nontaxable adjustments to contingent acquisition consideration and, starting in 2017, excess tax benefits related to share-based compensation.

The Company is routinely examined by tax authorities in the jurisdictions in which it has significant operations. The Company regularly considers the likelihood of assessments in each of the taxing jurisdictions resulting from examinations. When evaluating the potential imposition of penalties, the Company considers a number of relevant factors under penalty statutes, including appropriate disclosure of the tax return position, the existence of legal authority supporting the Company's position, and reliance on the opinion of professional tax advisors.

The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in tax returns. The Company's gross unrecognized tax benefits decreased from $65 million at December 31, 2016 to $64 million at September 30, 2017 due to settlements of audits and expirations of statutes of limitation, partially offset by current accruals. It is reasonably possible that the total amount of unrecognized tax benefits will decrease between zero and approximately $9 million within the next twelve months due to settlements of audits and expirations of statutes of limitation.