Variable Interest Entities (Changes in Level 3 Assets and Liabilities) (Details 2) - Variable Interest Entity, Primary Beneficiary [Member] - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Syndicated loans [Member]
Summary of changes in Level 3 assets measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period		$ 302	$ 117	$ 143	$ 226
Total gains (losses) included in net income	[1]	18	(1)	(21)	(1)
Purchases		2	27	45	49
Sales		(8)	(7)	(15)	(8)
Settlements		(16)	(4)	(26)	(11)
Transfers into Level 3		102	59	350	84
Transfers out of Level 3		(189)	(61)	(265)	(209)
Balance, at the end of the period		211	130	211	130
Changes in unrealized gains (losses) included in income relating to assets held at end of period	[1]	$ 17	(1)	$ 3	(1)
Common stocks [Member]
Summary of changes in Level 3 assets measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period			0		0
Transfers into Level 3			1		1
Balance, at the end of the period			$ 1		$ 1

[1] Included in net investment income in the Consolidated Statements of Operations.