SCHEDULE IV - REINSURANCE (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reinsurance
Gross amount	$ 30,654	$ 29,969	$ 29,950
Ceded to other companies	1,764	1,848	1,896
Assumed from other companies	88	59	71
Net amount	28,978	28,180	28,125
Percentage of amount assumed to net	0.30%	0.20%	0.30%
Life insurance in force
Reinsurance
Gross amount	521,209	519,639	523,214
Ceded to other companies	209,874	222,379	238,745
Assumed from other companies	14,834	9,137	9,680
Net amount	326,169	306,397	294,149
Percentage of amount assumed to net	4.50%	3.00%	3.30%
Life insurance
Reinsurance
Gross amount	2,089	2,177	2,170
Ceded to other companies	556	617	659
Assumed from other companies	55	35	36
Net amount	1,588	1,595	1,547
Percentage of amount assumed to net	3.50%	2.20%	2.30%
Accident and health insurance
Reinsurance
Gross amount	771	776	765
Ceded to other companies	118	133	145
Assumed from other companies			1
Net amount	653	643	621
Percentage of amount assumed to net			0.20%
Property-liability insurance
Reinsurance
Gross amount	27,794	27,016	27,015
Ceded to other companies	1,090	1,098	1,092
Assumed from other companies	33	24	34
Net amount	$ 26,737	$ 25,942	$ 25,957
Percentage of amount assumed to net	0.10%	0.10%	0.10%