Variable Interest Entities (Changes in Level 3 Assets and Liabilities) (Details 2) - Consolidated investment entities [Member] - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
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	$ 11	$ 0	$ 4
Total gains (losses) included in net income	[1]				4
Sales			(4)		(4)
Transfers into Level 3		1		1	4
Transfers out of Level 3			(3)		(4)
Balance, at the end of the period		1	4	1	4
Changes in unrealized gains (losses) included in income relating to assets held at end of period	[1]				2
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		117	200	226	180
Total gains (losses) included in net income	[1]	(1)	(1)	(1)	1
Purchases		27	24	49	42
Sales		(7)	(35)	(8)	(36)
Settlements		(4)	(19)	(11)	(30)
Transfers into Level 3		59	17	84	78
Transfers out of Level 3		(61)	(75)	(209)	(124)
Balance, at the end of the period		130	$ 111	130	$ 111
Changes in unrealized gains (losses) included in income relating to assets held at end of period	[1]	$ (1)		$ (1)

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