Goodwill, Other Intangibles, and Property and Equipment (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 6,001	$ 3,164
Impact of foreign currency translation	(8)	8
Goodwill, Ending Balance	6,029	6,001
Finans Emeklilik [Member]
Goodwill [Line Items]
Goodwill acquired	3	113
FirstAssist [Member]
Goodwill [Line Items]
Goodwill acquired	0	7
HealthSpring [Member]
Goodwill [Line Items]
Goodwill acquired	0	2,541
Great American Supplemental Benefits Group [Member]
Goodwill [Line Items]
Goodwill acquired	0	168
Other [Member]
Goodwill [Line Items]
Goodwill acquired	33
Global Health Care [Member]
Goodwill [Line Items]
Goodwill, Ending Balance	5,700
Global Supplemental Benefits [Member]
Goodwill [Line Items]
Goodwill, Ending Balance	$ 340