Equity (Details) (USD $) In Millions, except Per Share data	3 Months Ended		9 Months Ended						0 Months Ended		1 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Parent [Member]	Sep. 30, 2010 Parent [Member]	Sep. 30, 2011 Noncontrolling Interest [Member]	Sep. 30, 2010 Noncontrolling Interest [Member]	Oct. 27, 2011 Dividend Declared [Member]	Nov. 16, 2011 Dividend Declared [Member]	Dec. 14, 2011 Dividend Declared [Member]
Reconciliation of the beginning and ending balances of the carrying amount of equity
Balance at beginning of period			$ 15,025	$ 14,725	$ 15,025	$ 14,725	$ 0	$ 0
Net income	1,203	292	2,044	762	2,045	762	(1)	0
Dividends			(85)	(85)	(85)	(85)	0	0
Stock-based compensation expense			34	32	34	32	0	0
Tax deduction in excess of stock-based compensation expense			19	7	19	7	0	0
Transactions in connection with stock-based compensation plans:
Stock issuances			42	12	42	12	0	0
Stock repurchases			(270)	(2)	(270)	(2)	0	0
Contributions from noncontrolling interest			14	0	0	0	14	0
Recognition of noncontrolling interest in connection with Pembroke Acquisition			3	0	0	0	3	0
Other comprehensive income (loss)	(266)	74	(156)	(51)	(156)	(51)	0	0
Balance at end of period	$ 16,670	$ 15,400	$ 16,670	$ 15,400	$ 16,654	$ 15,400	$ 16	$ 0
Equity (Textual)
Shares of common stock repurchased			13.6	1.6
Shares of common stock issued from treasury			3.9	1.6
Dividends payable, date declared									Oct. 27, 2011
Dividends payable, amount per share									$ 0.15
Dividends payable, date to be paid											Dec. 14, 2011
Dividends payable, date of record										Nov. 16, 2011