Reinsurance (Reinsurance Amounts Recorded on Consolidated Statements of Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reinsurance [Abstract]
Direct insurance premiums and fee income	$ 13,498	$ 12,041	$ 10,269
Reinsurance assumed	91	89	91
Reinsurance ceded	(1,579)	(1,543)	(1,485)
Total insurance premiums and fee income	12,010	10,587	8,875
Direct insurance benefits	9,574	8,592	6,770
Reinsurance recoveries netted against benefits	(1,694)	(1,806)	(1,610)
Benefits	$ 7,880	$ 6,786	$ 5,160