SCHEDULE IV REINSURANCE Schedule IV - Reinsurance (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	$ 146,610				$ 144,374				$ 146,610	$ 144,374	$ 157,022
Ceded to Other Companies	3,547				3,298				3,547	3,298	3,245
Assumed from Other Companies	0				0				0	0	0
Net Amount	$ 143,063				$ 141,076				$ 143,063	$ 141,076	$ 153,777
Percentage of Amount Assumed to Net	0.00%				0.00%				0.00%	0.00%	0.00%
Gross amount									$ 17,904	$ 19,412	$ 20,233
Ceded to Other Companies									520	350	110
Assumed from Other companies									186	10	12
Net Amount	$ 4,394	$ 4,380	$ 4,364	$ 4,432	$ 4,489	$ 4,841	$ 4,888	$ 4,854	$ 17,570	$ 19,072	$ 20,135
Percentage of Amount Assumed to Net									1.00%	0.00%	0.00%
Health insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									$ 13,604	$ 14,648	$ 15,393
Ceded to Other Companies									509	339	98
Assumed from Other companies									186	10	12
Net Amount									$ 13,281	$ 14,319	$ 15,307
Percentage of Amount Assumed to Net									1.00%	0.00%	0.00%
Life insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									$ 4,300	$ 4,764	$ 4,840
Ceded to Other Companies									11	11	12
Assumed from Other companies									0	0	0
Net Amount									$ 4,289	$ 4,753	$ 4,828
Percentage of Amount Assumed to Net									0.00%	0.00%	0.00%