Goodwill And Other Intangibles (Changes In The Carrying Amount Of Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Goodwill [Roll Forward]
Balance as of January 1, as reported	$ 6,420	[1]	$ 5,990	[1]
Goodwill acquired	124		502
Other adjustments	18	[2]	(72)	[2]
Balance at December 31,	$ 6,562		$ 6,420	[1]

[1] Amounts in 2010 exclude goodwill and accumulated impairment losses related to Kroll, which were reclassified to discontinued operations.

[2] Primarily purchase accounting adjustments and foreign exchange.