SCHEDULE IV - CONSOLIDATED REINSURANCE (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated reinsurance, net [Abstract]
Premiums Earned, Net, Total		$ 3,256	$ 2,987	$ 3,246
Embedded derivatives - Reinsurance related [Member]
Consolidated reinsurance, net [Abstract]
Gross Amount		10,269	9,551	9,529
Ceded to Other Companies		1,485	1,413	1,311
Assumed from Other Companies		91	93	73
Premiums Earned, Net, Total		8,875	8,231	8,291
Gross Amount, Life Insurance in Force	[1]	1,075,600	1,035,600	1,032,900
Ceded to Other Companies, Life Insurance in Force	[1]	286,600	288,000	287,400
Assumed from Other Companies, Life Insurance in Force	[1]	9,500	10,200	10,400
Premiums, Net, Life Insurance in Force, Total	[1]	$ 798,500	$ 757,800	$ 755,900
Percentage of Amount Assumed to Net, Life Insurance in Force	[1]	1.20%	1.30%	1.40%
Life insurance and annuities [Member] | Embedded derivatives - Reinsurance related [Member]
Consolidated reinsurance, net [Abstract]
Gross Amount	[2]	$ 8,949	$ 8,277	$ 8,112
Ceded to Other Companies	[2]	1,465	1,392	1,289
Assumed from Other Companies	[2]	80	80	58
Premiums Earned, Net, Total	[2]	$ 7,564	$ 6,965	$ 6,881
Percentage of Amount Assumed to Net	[2]	1.10%	1.10%	0.80%
Accident and health insurance [Member] | Embedded derivatives - Reinsurance related [Member]
Consolidated reinsurance, net [Abstract]
Gross Amount		$ 1,320	$ 1,274	$ 1,417
Ceded to Other Companies		20	21	22
Assumed from Other Companies		11	13	15
Premiums Earned, Net, Total		$ 1,311	$ 1,266	$ 1,410
Percentage of Amount Assumed to Net		0.80%	1.00%	1.10%

[1] Includes Group Protection segment and Other Operations in-force amounts.

[2] Includes insurance fees on universal life and other interest-sensitive products.