Acquisitions (Pro-Forma Information) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Acquisitions [Abstract]
Revenue	$ 11,563	$ 10,839	$ 10,436
Income from continuing operations	985	580	572
Net income attributable to the Company	$ 996	$ 870	$ 268
Basic net income per share - Continuing operations	$ 1.77	$ 1.03	$ 1.02
Basic net income per share - Net income attributable to the Company	$ 1.83	$ 1.59	$ 0.49
Diluted net income per share - Continuing operations	$ 1.74	$ 1.02	$ 1.01
Diluted net income per share - Net income attributable to the Company	$ 1.80	$ 1.57	$ 0.49

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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