Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income Statement [Abstract]
Revenue	$ 2,845	$ 2,806	$ 8,922	$ 8,618
Expense:
Compensation and benefits	1,760	1,753	5,332	5,202
Other operating expenses	707	743	2,167	2,169
Operating expenses	2,467	2,496	7,499	7,371
Operating Income	378	310	1,423	1,247
Interest income	6	9	18	21
Interest expense	(44)	(49)	(135)	(149)
Cost of extinguishment of debt	0	(72)	0	(72)
Investment (loss) income	(4)	0	20	13
Income before income taxes	336	198	1,326	1,060
Income tax expense	90	65	387	322
Income from continuing operations	246	133	939	738
Discontinued operations, net of tax	1	2	(1)	17
Net income before non-controlling interest	247	135	938	755
Less: Net income attributable to non-controlling interests	6	5	21	18
Net income attributable to the Company	$ 241	$ 130	$ 917	$ 737
Basic net income per share
- Continuing operations	$ 0.44	$ 0.24	$ 1.68	$ 1.32
- Net income attributable to the Company	$ 0.44	$ 0.24	$ 1.68	$ 1.35
Diluted net income per share
- Continuing operations	$ 0.43	$ 0.23	$ 1.66	$ 1.30
- Net income attributable to the Company	$ 0.44	$ 0.24	$ 1.66	$ 1.33
Average number of shares outstanding
- Basic (in shares)	544	540	544	543
- Diluted (in shares)	552	549	552	552
Shares outstanding at September 30, (in shares)	544	538	544	538