Segment Information (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Segment Reporting Information [Line Items]
Net income	$ 24	$ 76	$ 535	$ 395
Property & Casualty Commercial [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	121	270	448	476
Group Benefits [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	41	48	52	99
Consumer Markets [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	(174)	(13)	(64)	43
Global Annuity [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	228	(114)	278	(34)
Life Insurance [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	66	103	101	127
Retirement Plans [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	30	14	45	8
Mutual Funds [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	27	23	55	49
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information, Profit (Loss)	$ (315)	$ (255)	$ (380)	$ (373)