Equity (Details) (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended						0 Months Ended		1 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 Parent [Member]	Jun. 30, 2010 Parent [Member]	Jun. 30, 2011 Noncontrolling Interest [Member]	Jun. 30, 2010 Noncontrolling Interest [Member]	Jul. 28, 2011 Dividend Declared [Member]	Aug. 18, 2011 Dividend Declared [Member]	Sep. 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	743	583	841	470	842	470	(1)	0
Dividends			(57)	(57)	(57)	(57)	0	0
Stock-based compensation expense			23	22	23	22	0	0
Tax deduction in excess of stock-based compensation expense			11	7	11	7	0	0
Transactions in connection with stock-based compensation plans:
Stock issuances			30	11	30	11	0	0
Stock repurchases			(2)	(2)	(2)	(2)	0	0
Equity interest in noncontrolling interest			11	0	0	0	11	0
Other comprehensive income (loss)	19	(192)	110	(125)	110	(125)	0	0
Balance at end of period	$ 15,992	$ 15,051	$ 15,992	$ 15,051	$ 15,982	$ 15,051	$ 10	$ 0
Equity (Textual)
Dividends payable, date declared									Jul. 28, 2011
Dividends payable, amount per share									$ 0.05
Dividends payable, date to be paid											Sep. 14, 2011
Dividends payable, date of record										Aug. 17, 2011