Consolidated Statements of Stockholders Equity (USD $) In Millions, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Securities Exchangeable for Common Stock[Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2011	$ 17,159	$ 0	$ 770	$ 0	$ (2,716)	$ 6,680	$ 12,788	$ (370)	$ 7
Treasury shares at Dec. 31, 2011					66
Shares Beginning Balance at Dec. 31, 2011			770
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock based compensation	89				164	(75)
Shares repurchased	(8)				(8)
Stock-based compensation	22					22
Net income	1,582						1,582
Other Comprehensive Income (Loss), Net of Tax, Incl Disc Ops	(63)							(63)
Dividends paid	(480)						(480)
Purchase of subsidiary shares from non-controlling interest	(7)								(7)
Other	(11)					(11)
Shares issued - stock based compensation					(3)
Ending Balance at Dec. 31, 2012	18,283	0	770	0	(2,560)	6,616	13,890	(433)	0
Treasury shares at Dec. 31, 2012					63
Shares Ending Balance at Dec. 31, 2012			770
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock based compensation	126				170	(44)
Shares repurchased	(513)				(513)
Stock-based compensation	20					20
Net income	1,753						1,753
Other Comprehensive Income (Loss), Net of Tax, Incl Disc Ops	183							183
Dividends paid	(508)						(508)
Shares issued - stock based compensation					(4)
Shares repurchased					14
Ending Balance at Dec. 31, 2013	19,344	0	770	0	(2,903)	6,592	15,135	(250)	0
Treasury shares at Dec. 31, 2013	73				73
Shares Ending Balance at Dec. 31, 2013			770
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - stock based compensation	219				276	(57)
Shares repurchased	(1,015)				(1,015)
Stock-based compensation	(4)					(4)
Net income	3,046						3,046
Other Comprehensive Income (Loss), Net of Tax, Incl Disc Ops	(27)							(27)
Dividends paid	(543)						(543)
Shares issued - stock based compensation					(7)
Shares repurchased					29
Ending Balance at Dec. 31, 2014	$ 21,020	$ 0	$ 770	$ 0	$ (3,642)	$ 6,531	$ 17,638	$ (277)	$ 0
Treasury shares at Dec. 31, 2014	95				95
Shares Ending Balance at Dec. 31, 2014			770