SCHEDULE IV - REINSURANCE (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Life Insurance In-Force
Gross Amount						$ 392,926	$ 399,230	$ 406,240
Ceded to Other Companies						41,330	78,760	82,927
Assumed from Other Companies						30,300	31,722	31,427
Net Amount						381,896	352,192	354,740
Premiums:
Gross Amount						880	850	818
Ceded to Other Companies						171	176	173
Assumed from Other Companies						195	206	207
Premiums	$ 208	$ 225	$ 232	$ 457	$ 665	$ 904	$ 880	$ 852
Life Insurance In-Force, Percentage of Amount Assumed to Net						7.90%	9.00%	8.90%
Premiums, Percentage of Amount Assumed to Net						21.60%	23.40%	24.30%
Life insurance and annuities
Premiums:
Gross Amount						$ 826	$ 790	$ 751
Ceded to Other Companies						135	135	128
Assumed from Other Companies						186	197	197
Premiums						$ 877	$ 852	$ 820
Premiums, Percentage of Amount Assumed to Net						21.20%	23.10%	24.00%
Accident and health
Premiums:
Gross Amount						$ 54	$ 60	$ 67
Ceded to Other Companies						36	41	45
Assumed from Other Companies						9	9	10
Premiums						$ 27	$ 28	$ 32
Premiums, Percentage of Amount Assumed to Net						33.30%	32.10%	31.30%