Reinsurance (Effects of Reinsurance on Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Premiums:
Direct Premiums	$ 42,513	$ 44,199	$ 39,595
Reinsurance assumed	2,020	2,021	1,773
Reinsurance ceded	(2,298)	(2,380)	(2,376)
Net premiums	42,235	43,840	38,992
Universal life and investment-type product policy fees:
Direct universal life and investment-type product policy fees	6,109	6,008	5,978
Reinsurance assumed	56	86	83
Reinsurance ceded	(562)	(592)	(551)
Net universal life and investment product policy fees	5,603	5,502	5,510
Policyholder Benefits and Claims:
Direct policyholder benefits and claims	42,094	43,456	39,354
Reinsurance assumed	1,584	1,583	1,388
Reinsurance ceded	(2,217)	(2,383)	(2,429)
Net policyholder benefits and claims	41,461	42,656	38,313
Other expenses:
Direct other expenses	13,559	13,704	13,610
Reinsurance assumed	382	321	246
Reinsurance ceded	252	311	235
Total other expenses	$ 13,689	$ 13,714	$ 13,621