Segment Information 4 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	$ 31,003	$ 27,931	$ 20,657
United States [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	27,868	25,217	18,522
South Korea [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	1,277	1,076	909
All Other Foreign [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	1,858	1,638	1,226
Medical [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	22,933	20,973	14,443
Disability [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	1,616	1,413	1,268
Life Accident And Health [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	4,322	3,680	3,117
Mail Order Pharmacy [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	1,827	1,623	1,447
Other Products [Member]
Segment Reporting Information [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	$ 305	$ 242	$ 382