Variable Interest Entities (Changes in Level 3 Assets and Liabilities) (Details 2) - Consolidated investment entities [Member] - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Rollforward]
Transfers from Level 1 to Level 2, assets		$ 0	$ 0	$ 0	$ 0
Transfers from Level 2 to Level 1, assets		0	0	0	0
Transfers from Level 1 to Level 2, liabilities		0	0	0	0
Transfers from Level 2 to Level 1, liabilities		0	0	0	0
Corporate debt securities [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
Sales				(2)
Transfers into Level 3				2
Balance, at the end of the period		0		0
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		7	1	5	3
Total gains (losses) included in net income	[1]	1		1
Purchases			1	3	1
Sales				(1)
Transfers into Level 3			1	2	3
Transfers out of Level 3		(4)		(6)	(2)
Balance, at the end of the period		4	3	4	3
Changes in unrealized gains (losses) included in income relating to assets held at end of period	[1]	1		1
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		185	243	254	529
Total gains (losses) included in net income	[1]	(1)	2		1
Purchases		6	50	133	100
Sales		(12)	(10)	(27)	(11)
Settlements		(3)	(26)	(56)	(51)
Transfers into Level 3		84	57	197	286
Transfers out of Level 3		(77)	(120)	(319)	(354)
Balance, at the end of the period		$ 182	196	182	196
Changes in unrealized gains (losses) included in income relating to assets held at end of period	[1]		2	$ (2)	1
Other assets [Member]
Summary of changes in Level 3 assets measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period			1		2,065
Total gains (losses) included in net income	[2]				1
Balance, at the end of the period			1		1
Debt [Member]
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period					(6,630)
Balance, at the end of the period			$ 0		0
Cumulative effect of change in accounting policies [Member] | 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	[3]				(2)
Cumulative effect of change in accounting policies [Member] | 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	[3]				(304)
Cumulative effect of change in accounting policies [Member] | Other assets [Member]
Summary of changes in Level 3 assets measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period	[3]				(2,065)
Cumulative effect of change in accounting policies [Member] | Debt [Member]
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period	[3]				6,630
Adjusted for change in accounting policies [Member] | 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					1
Adjusted for change in accounting policies [Member] | 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					225
Adjusted for change in accounting policies [Member] | Other assets [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
Adjusted for change in accounting policies [Member] | Debt [Member]
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Rollforward]
Balance, at the beginning of the period					$ 0

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

[2] Included in other revenues in the Consolidated Statements of Operations.

[3] The cumulative effect of change in accounting policies includes the adoption impact of ASU 2015-02 and ASU 2014-13 – Consolidation: Measuring the Financial Assets and the Financial Liabilities of a Consolidated Collateralized Financing Entity (“ASU 2014-13”).