Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Exchange traded equity securities			$ 1
Mutual funds	134	[1]	137	[1]
Money market funds	226	[2]	8	[2]
Interest rate swap derivatives	7	[3]
Total assets measured at fair value	367		146
State and local obligations (including non-U.S. locales)	13		68
Other sovereign government obligations and supranational agencies	47		185
Corporate and other debt	2		30
Money market funds	186		152
Total fiduciary assets measured at fair value	248		435
Contingent consideration liability	110	[4]	106	[4]
Senior Notes due 2014	257	[5]
Total liabilities measured at fair value	367		106
Identical Assets (Level 1) [Member]
Exchange traded equity securities			1
Mutual funds	134	[1]	137	[1]
Money market funds	226	[2]	8	[2]
Total assets measured at fair value	360		146
Money market funds	186		152
Total fiduciary assets measured at fair value	186		152
Observable Inputs (Level 2) [Member]
Interest rate swap derivatives	7	[3]
Total assets measured at fair value	7
State and local obligations (including non-U.S. locales)	13		68
Other sovereign government obligations and supranational agencies	47		185
Corporate and other debt	2		30
Total fiduciary assets measured at fair value	62		283
Senior Notes due 2014	257	[5]
Total liabilities measured at fair value	257
Unobservable Inputs (Level 3) [Member]
Contingent consideration liability	110	[4]	106	[4]
Total liabilities measured at fair value	$ 110		$ 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 other receivables in the consolidated balance sheets.

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

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