Variable Interest Entities (Change in Level 3 Assets and Liabilities) (Details 2) (Consolidated investment entities [Member], USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Summary of changes in Level 3 assets held by consolidated investment entities
Transfers between Level 1 and Level 2	$ 0
Corporate debt securities [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	2,000,000		3,000,000		4,000,000
Total gains (losses) included in net income	1,000,000	[1]
Purchases	2,000,000		1,000,000
Sales	(9,000,000)		(1,000,000)
Settlements			(1,000,000)		(1,000,000)
Transfers into Level 3	10,000,000
Transfers out of Level 3	(6,000,000)
Balance, at the end of the period	0		2,000,000		3,000,000
Common stocks [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	14,000,000		14,000,000		13,000,000
Total gains (losses) included in net income	1,000,000	[1]	1,000,000	[1]	(1,000,000)	[1]
Purchases					7,000,000
Sales	(2,000,000)		(3,000,000)		(5,000,000)
Transfers into Level 3	13,000,000		21,000,000		15,000,000
Transfers out of Level 3	(19,000,000)		(19,000,000)		(15,000,000)
Balance, at the end of the period	7,000,000		14,000,000		14,000,000
Changes in unrealized gains/ (losses) included in income relating to assets held at end of period			(2,000,000)	[1]
Syndicated loans [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	368,000,000		202,000,000		342,000,000	[1]
Total gains (losses) included in net income	2,000,000	[1]	(1,000,000)	[1]	11,000,000	[1]
Purchases	417,000,000		417,000,000		91,000,000
Sales	(42,000,000)		(63,000,000)		(14,000,000)
Settlements	(100,000,000)		(51,000,000)		(87,000,000)
Transfers into Level 3	551,000,000		320,000,000		255,000,000
Transfers out of Level 3	(712,000,000)		(456,000,000)		(396,000,000)
Balance, at the end of the period	484,000,000		368,000,000		202,000,000
Changes in unrealized gains/ (losses) included in income relating to assets held at end of period	(3,000,000)	[1]	(2,000,000)	[1]
Other assets [Member]
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	1,936,000,000		1,214,000,000		1,108,000,000
Total gains (losses) included in net income	421,000,000	[2]	81,000,000	[2]	(78,000,000)	[3]
Total gains (losses) included in other comprehensive income (loss)	(175,000,000)		39,000,000		28,000,000
Purchases	289,000,000		689,000,000		328,000,000
Sales	(547,000,000)		(86,000,000)		(172,000,000)
Transfers into Level 3	11,000,000		8,000,000
Transfers out of Level 3			(9,000,000)
Balance, at the end of the period	1,935,000,000		1,936,000,000		1,214,000,000
Changes in unrealized gains/ (losses) included in income relating to assets held at end of period	362,000,000	[2]	67,000,000	[2]	(98,000,000)	[3]
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	(4,804,000,000)		(4,450,000,000)		(4,712,000,000)
Total gains (losses) included in net income	(34,000,000)	[1]	(53,000,000)	[1]	(316,000,000)	[1]
Issues	(1,670,000,000)		(1,330,000,000)
Settlements	478,000,000		1,029,000,000		578,000,000
Balance, at the end of the period	(6,030,000,000)		(4,804,000,000)		(4,450,000,000)
Changes in unrealized gains/ (losses) included in income relating to liabilities held at end of period	$ 1,000,000	[1]	$ (25,000,000)	[1]	$ (315,000,000)	[1]

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

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

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