Consolidated Statement of Shareholder's Interest (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Shareholder's Interest [Roll Forward]
Balance at beginning of period	$ 11,367	$ 10,604
Net income	306	312
Net Income (Loss) Attributable to Noncontrolling Interest	0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	306	312
Other Comprehensive Income (Loss), Net of Tax	(482)	(82)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest	1	0
Distributions	(28)	(28)
Balance at end of period	11,162	10,806
Stockholders' Equity Attributable to Noncontrolling Interest	1	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	11,163	10,806
Shareholder's Interest [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period	5,227	5,217
Net income	0	0
Other Comprehensive Income (Loss), Net of Tax	0	0
Distributions	0	0
Balance at end of period	5,227	5,217
Accumulated Other Comprehensive Income/(Loss) (Note10) [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period	160	717
Net income	0	0
Other Comprehensive Income (Loss), Net of Tax	(483)	(82)
Distributions	0	0
Balance at end of period	(323)	635
Retained Earnings [Member]
Shareholder's Interest [Roll Forward]
Balance at beginning of period	5,980	4,670
Net income	306	312
Other Comprehensive Income (Loss), Net of Tax	0	0
Distributions	(28)	(28)
Balance at end of period	6,258	4,954
Parent [Member]
Shareholder's Interest [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	(483)	(82)
Distributions	(28)	(28)
Noncontrolling Interest [Member]
Shareholder's Interest [Roll Forward]
Distributions	$ 0	$ 0