Consolidated Reinsurance (Consolidated Reinsurance) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Direct Premiums, Life Insurance in Force	$ 4,963,820	$ 4,594,523	$ 4,098,780
Ceded Premiums, Life Insurance in Force	507,589	513,091	481,028
Assumed Premiums, Life Insurance in Force	532,511	581,246	613,693
Premiums, Net, Life Insurance in Force	$ 4,988,742	$ 4,662,678	$ 4,231,445
Life Insurance in Force Premiums, Percentage Assumed to Net	10.70%	12.50%	14.50%
Consolidated Reinsurance
Gross Amount	$ 44,199	$ 39,595	$ 37,975
Ceded	2,380	2,376	2,136
Assumed	2,021	1,773	1,363
Premiums	$ 43,840	$ 38,992	$ 37,202
% Amount Assumed to Net	4.60%	4.50%	3.70%
Life insurance (1)
Consolidated Reinsurance
Gross Amount	$ 26,356	$ 22,379	$ 20,857
Ceded	1,792	1,863	1,614
Assumed	1,791	1,531	1,089
Premiums	$ 26,355	$ 22,047	$ 20,332
% Amount Assumed to Net	6.80%	6.90%	5.40%
Accident & health insurance
Consolidated Reinsurance
Gross Amount	$ 14,166	$ 13,593	$ 13,551
Ceded	515	442	447
Assumed	212	223	257
Premiums	$ 13,863	$ 13,374	$ 13,361
% Amount Assumed to Net	1.50%	1.70%	1.90%
Property and casualty insurance
Consolidated Reinsurance
Gross Amount	$ 3,677	$ 3,623	$ 3,567
Ceded	73	71	75
Assumed	18	19	17
Premiums	$ 3,622	$ 3,571	$ 3,509
% Amount Assumed to Net	0.50%	0.50%	0.50%