Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000062709 (http://www.sec.gov/CIK)

Goodwill and Intangible Assets Disclosure [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in the Carrying Amount of Goodwill	Changes in the carrying amount of goodwill are as follows:  (In millions of dollars) 2016   2015 Balance as of January 1, as reported $ 7,889   $ 7,241 Goodwill acquired 556   783 Other adjustments(a) (76 )   (135 ) Balance at December 31, $ 8,369   $ 7,889 (a) Primarily due to the impact of foreign exchange in both years.
Schedule of Finite-Lived Intangible Assets	The gross cost and accumulated amortization at December 31, 2016 and 2015 are as follows: (In millions of dollars) 2016   2015 Gross Cost   Accumulated Amortization   Net Carrying Amount   Gross Cost   Accumulated Amortization   Net Carrying Amount Client relationships $ 1,390   $ 392   $ 998   $ 1,281   $ 347   $ 934 Other (a) 204   76   128   176   74   102 Amortized intangibles $ 1,594   $ 468   $ 1,126   $ 1,457   $ 421   $ 1,036 (a) Primarily non-compete agreements, trade names and developed technology
Estimated Future Aggregate Amortization Expense	The estimated future aggregate amortization expense is as follows: For the Years Ending December 31,   (In millions of dollars)   2017 $ 148 2018 141 2019 134 2020 120 2021 107 Subsequent years 476   $ 1,126