Reinsurance (Effects of Reinsurance on Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premiums:
Direct Premiums	$ 44,199	$ 39,595	$ 37,975
Reinsurance assumed	2,021	1,773	1,363
Reinsurance ceded	(2,380)	(2,376)	(2,136)
Net premiums	43,840	38,992	37,202
Universal life and investment-type product policy fees:
Direct universal life and investment-type product policy fees	6,008	5,978	5,884
Reinsurance assumed	86	83	96
Reinsurance ceded	(592)	(551)	(497)
Net universal life and investment product policy fees	5,502	5,510	5,483
Policyholder Benefits and Claims:
Direct policyholder benefits and claims	43,456	39,354	37,186
Reinsurance assumed	1,583	1,388	1,085
Reinsurance ceded	(2,383)	(2,429)	(1,913)
Net policyholder benefits and claims	42,656	38,313	36,358
Other expenses:
Direct other expenses	13,704	13,610	13,958
Reinsurance assumed	321	246	169
Reinsurance ceded	311	235	378
Total other expenses	$ 13,714	$ 13,621	$ 13,749