Earnings Per Share (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Antidilutive Options [Table] [Abstract]
Antidilutive options																	2,500,000	3,700,000	6,300,000
Earnings Per Share (Details) [Abstract]
Shareholders' net income	$ 406	[1]	$ 466	[2]	$ 380	[3]	$ 371	[4]	$ 273	[5]	$ 183	[6]	$ 391	[7]	$ 413	[8]	$ 1,623	$ 1,260	$ 1,279
Shares (in thousands):
Weighted average																	284,819,000	270,691,000	272,866,000
Common stock equivalents																	4,711,000	3,558,000	2,421,000
Total shares																	289,530,000	274,249,000	275,287,000
Shareholders' net income per share basic	$ 1.43		$ 1.64		$ 1.33		$ 1.30		$ 0.99		$ 0.68		$ 1.46		$ 1.53		$ 5.70	$ 4.65	$ 4.69
Shareholders net income per share effect of dilution																	$ (0.09)	$ (0.06)	$ (0.04)
Shareholders' net income per share diluted	$ 1.41		$ 1.61		$ 1.31		$ 1.28		$ 0.98		$ 0.67		$ 1.43		$ 1.51		$ 5.61	$ 4.59	$ 4.65

[1] The fourth quarter of 2012 includes an after-tax gain of $7 million for the GMIB business and an after-tax charge of $68 million for litigation matters

[2] The third quarter of 2012 includes an after-tax gain of $32 million for the GMIB business, an after-tax charge of $12 million for costs associated with acquisitions, and an after-tax charge of $50 million for costs associated with a realignment and efficiency plan.

[3] The second quarter of 2012 includes an after-tax loss of $51 million for the GMIB business.

[4] The first quarter of 2012 includes an after-tax gain of $41 million for the GMIB business, an after-tax charge of $28 million for costs associated with acquisitions, and an after-tax charge of $13 million for costs associated a litigation matter in Global Health Care.

[5] The fourth quarter of 2011 includes an after-tax gain of $7 million for the GMIB business and, an after-tax charge of $31 million for costs associated with acquisitions.

[6] The third quarter of 2011 includes an after-tax loss of $134 million for the GMIB business.

[7] The second quarter of 2011 includes an after-tax loss of $21 million for the GMIB business.

[8] The first quarter of 2011 includes an after-tax gain of $13 million for the GMIB business and a net tax benefit of $24 million related to the resolution of a Federal tax matter.