SCHEDULE IV REINSURANCE Schedule IV - Reinsurance (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount, Life Insurance in Force	$ 151,093				$ 146,610				$ 151,093	$ 146,610	$ 144,374
Ceded to Other Companies, Life Insurance in Force	3,741				3,547				3,741	3,547	3,298
Assumed from Other Companies, Life Insurance in Force	0				0				0	0	0
Net Amount, Life Insurance in Force	$ 147,352				$ 143,063				$ 147,352	$ 143,063	$ 141,076
Percentage of Amount Assumed to Net, Life Insurance in Force	0.00%				0.00%				0.00%	0.00%	0.00%
Gross amount									$ 19,592	$ 17,904	$ 19,412
Ceded to Other Companies									608	520	350
Assumed from Other companies									241	186	10
Net Amount	$ 4,778	$ 5,022	$ 4,823	$ 4,602	$ 4,394	$ 4,380	$ 4,364	$ 4,432	$ 19,225	$ 17,570	$ 19,072
Percentage of Amount Assumed to Net									1.00%	1.00%	0.00%
Health insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									$ 14,839	$ 13,604	$ 14,648
Ceded to Other Companies									595	509	339
Assumed from Other companies									241	186	10
Net Amount									$ 14,485	$ 13,281	$ 14,319
Percentage of Amount Assumed to Net									1.00%	1.00%	0.00%
Life insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									$ 4,753	$ 4,300	$ 4,764
Ceded to Other Companies									13	11	11
Assumed from Other companies									0	0	0
Net Amount									$ 4,740	$ 4,289	$ 4,753
Percentage of Amount Assumed to Net									0.00%	0.00%	0.00%