Consolidated Statements of Changes in Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income, Net [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2012	$ 15,910	$ 0	$ 5,423	$ 10,782	$ (463)	$ 168
Balance (shares) at Dec. 31, 2012		75
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,290	0	0	1,274	0	16
Other comprehensive income	240	0	0	0	240	0
Distributions	(16)	0	0	0	0	(16)
Redemption of preferred securities of subsidiaries	(32)	0	0	0	0	(32)
Other equity transactions	(29)	0	(33)	0	0	4
Balance at Sep. 30, 2013	17,363	0	5,390	12,056	(223)	140
Balance (shares) at Sep. 30, 2013		75
Balance at Dec. 31, 2013	18,816	0	6,390	12,418	(97)	105
Balance (shares) at Dec. 31, 2013	77	77
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,709	0	0	1,696	0	13
Other comprehensive income	210	0	0	0	210	0
Distributions	(16)	0	0	0	0	(16)
Other equity transactions	53	0	33	0	0	20
Balance at Sep. 30, 2014	$ 20,772	$ 0	$ 6,423	$ 14,114	$ 113	$ 122
Balance (shares) at Sep. 30, 2014	77	77