Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions	Jun. 30, 2011		Dec. 31, 2010
Exchange traded equity securities		[1]	$ 1	[1]
Mutual funds	140	[1]	137	[1]
Medium term bond funds and fixed income securities		[1]		[1]
Money market funds	226	[2]	8	[2]
Interest rate swap derivatives	5	[1]		[1]
Total assets measured at fair value	371		146
State and local obligations (including non-U.S. locales)	35		68
Other sovereign government obligations and supranational agencies	140		185
Corporate and other debt	4		30
Money market funds	175		152
Total fiduciary assets measured at fair value	354		435
Contingent consideration liability	111	[3]	106	[3]
Senior Notes due 2014	255	[4]
Total liabilities measured at fair value	366		106
Identical Assets (Level 1) [Member]
Exchange traded equity securities		[1]	1	[1]
Mutual funds	140	[1]	137	[1]
Medium term bond funds and fixed income securities		[1]		[1]
Money market funds	226	[2]	8	[2]
Interest rate swap derivatives		[1]		[1]
Total assets measured at fair value	366		146
State and local obligations (including non-U.S. locales)
Other sovereign government obligations and supranational agencies
Corporate and other debt
Money market funds	175		152
Total fiduciary assets measured at fair value	175		152
Contingent consideration liability		[3]		[3]
Senior Notes due 2014		[4]		[4]
Total liabilities measured at fair value
Observable Inputs (Level 2) [Member]
Exchange traded equity securities		[1]		[1]
Mutual funds		[1]		[1]
Medium term bond funds and fixed income securities		[1]		[1]
Money market funds				[2]
Interest rate swap derivatives	5	[1]		[1]
Total assets measured at fair value	5
State and local obligations (including non-U.S. locales)	35		68
Other sovereign government obligations and supranational agencies	140		185
Corporate and other debt	4		30
Total fiduciary assets measured at fair value	179		283
Contingent consideration liability		[3]		[3]
Senior Notes due 2014	255	[4]		[4]
Total liabilities measured at fair value	255
Unobservable Inputs (Level 3) [Member]
Exchange traded equity securities		[1]		[1]
Mutual funds		[1]		[1]
Medium term bond funds and fixed income securities		[1]		[1]
Money market funds		[2]		[2]
Interest rate swap derivatives		[1]		[1]
Total assets measured at fair value
State and local obligations (including non-U.S. locales)
Other sovereign government obligations and supranational agencies
Corporate and other debt
Money market funds
Total fiduciary assets measured at fair value
Contingent consideration liability	111	[3]	106	[3]
Senior Notes due 2014		[4]		[4]
Total liabilities measured at fair value	$ 111		$ 106

[1] Included in other assets in the consolidated balance sheets.

[2] Included in cash and cash equivalents in the consolidated balance sheets.

[3] Included in accounts payable and accrued liabilities and in other liabilities in the consolidated balance sheets.

[4] Included in long term debt in the consolidated balance sheets.