Schedule IV - Reinsurance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Life insurance in force
Gross amount, Life insurance in force	$ 1,047,002	$ 1,047,982	$ 879,508
Ceded to other companies, Life insurance in force	55,399	72,208	58,133
Assumed from other companies, Life insurance in force	2,827	3,273	3,180
Net amount, Life Insurance In Force	994,430	979,047	824,555
Premiums:
Gross amount, premiums	30,755	29,812	27,215
Ceded to other companies, premiums	513	570	603
Assumed from other companies, premiums	384	400	602
Net amount	$ 30,626	$ 29,642	$ 27,214
Percentage of amount assumed to net, premiums	1.30%	1.30%	2.20%
Percentage of amount assumed to net, Life insurance in force	0.30%	0.30%	0.40%
Life insurance and annuities [Member]
Premiums:
Gross amount, premiums	$ 2,881	$ 2,886	$ 2,302
Ceded to other companies, premiums	310	335	320
Assumed from other companies, premiums	22	106	32
Net amount	$ 2,593	$ 2,657	$ 2,014
Percentage of amount assumed to net, premiums	0.80%	4.00%	1.60%
Accident and health insurance [Member]
Premiums:
Gross amount, premiums	$ 27,874	$ 26,926	$ 24,913
Ceded to other companies, premiums	203	235	283
Assumed from other companies, premiums	362	294	570
Net amount	$ 28,033	$ 26,985	$ 25,200
Percentage of amount assumed to net, premiums	1.30%	1.10%	2.30%