Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Segment Information [Abstract]
Realized Investment Gains Losses After Tax	$ 12	$ 17
Shareholders' income from continuing operations	371	413
Segment Text Detail [Abstract]
Percent International Revenues South Korea	29.00%
Precent International Earnings South Korea	40.00%
Health Care Segment [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	4,937	3,719
Segment income from continuing operations	242	247
Disability And Life Segment [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	743	688
Segment income from continuing operations	65	82
International Segment [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	875	704
Segment income from continuing operations	80	61
Run Off Reinsurance Segment [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	(90)	(34)
Segment income from continuing operations	30	13
Other Operations Segment [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	39	44
Segment income from continuing operations	20	23
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	(17)	(15)
Segment income from continuing operations	(78)	(30)
Total Segments [Member]
Segment Reporting Information [Line Items]
Premiums and fees, Mail order pharmacy revenues and Other revenues	6,487	5,106
Segment income from continuing operations	$ 359	$ 396