Variable Interest Entities (Change in Level 3 Assets and Liabilities) (Details 2) - Consolidated investment entities [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Corporate Debt Securities [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
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 held by consolidated investment entities
Balance, at the beginning of the period		4	5	3
Total gains (losses) included in net income	[1]	6	(1)	2
Purchases			3	1
Sales		(10)	(2)
Transfers into Level 3		4	7	3
Transfers out of Level 3		(2)	(8)	(2)
Transfers out of Level 3 from deconsolidation of collateralized loan obligations		(2)
Balance, at the end of the period		0	4	5
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 held by consolidated investment entities
Balance, at the beginning of the period		180	254	529
Total gains (losses) included in net income	[1]	(1)		7
Purchases		97	146	145
Sales		(41)	(28)	(24)
Settlements		(52)	(70)	(69)
Transfers into Level 3		173	266	405
Transfers out of Level 3		(160)	(388)	(435)
Transfers into Level 3 from consolidation of collateralized loan obligations		54
Transfers out of Level 3 from deconsolidation of collateralized loan obligations		(24)
Balance, at the end of the period		226	180	254
Changes in unrealized gains (losses) included in income relating to assets held at end of period	[1]	$ (4)	(1)	3
Other assets [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period			0	2,065
Total gains (losses) included in net income	[2]			1
Sales				(1)
Balance, at the end of the period				0
CLO Debt [Member]
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Roll Forward]
Balance, at the beginning of the period			$ 0	(6,630)
Balance, at the end of the period				0
Adjustments for New Accounting Pronouncement [Member] | Common stocks [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	[3]			(2)
Adjustments for New Accounting Pronouncement [Member] | Syndicated loans [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	[3]			(304)
Adjustments for New Accounting Pronouncement [Member] | Other assets [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	[3]			(2,065)
Adjustments for New Accounting Pronouncement [Member] | CLO Debt [Member]
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Roll Forward]
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 held by consolidated investment entities
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 held by consolidated investment entities
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 held by consolidated investment entities
Balance, at the beginning of the period				0
Adjusted for change in accounting policies [Member] | CLO Debt [Member]
Summary of changes in Level 3 liabilities measured at fair value on a recurring basis [Roll Forward]
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”).