Consolidated Investment Entities (Details 2) (Consolidated Investment Entities:, USD $) In Millions, unless otherwise specified	3 Months Ended			3 Months Ended
	Mar. 31, 2011 Corporate debt securities	Mar. 31, 2012 Corporate debt securities	Dec. 31, 2011 Corporate debt securities	Mar. 31, 2012 Common Shares	Mar. 31, 2011 Common Shares	Mar. 31, 2011 Other structured investments	Mar. 31, 2012 Syndicated loans	Mar. 31, 2011 Syndicated loans	Mar. 31, 2012 Other assets	Mar. 31, 2011 Other assets	Mar. 31, 2012 Debt	Mar. 31, 2011 Debt
Summary of changes in Level 3 assets held by consolidated investment entities
Balance, at the beginning of the period	$ 6	$ 4	$ 4	$ 13	$ 11	$ 22	$ 342		$ 1,108	$ 887
Balance, at the beginning of the period											(4,712)	(5,171)
Total Gains (Losses) Included in Net Income-Assets				(1)	5		3	4	(27)	4
Total Gains (Losses) Included in Net Income-Liabilities											(125)	(184)
Total Gains (Losses) Included in Net Income-Assets and included in Other Revenues in the Consolidated Statement of Operations										3
Total Gains (Losses) Included in Net Income-Assets and included in Net Investment Income in the Consolidated Statement of Operations										(1)
Total Gains (Losses) Included in Other Comprehensive Income-Assets									32	24
Purchases, Net-Assets				6			7	26	12	12
Sales, Net-Assets	(1)			(2)			(5)	(2)	(90)	(15)
Settlements, Net-Assets							30	3		1
Issues, Net-Liabilities												(10)
Settlements, Net-Liabilities											68	32
Transfers into Level 3	1			1	11	22	86	192		7
Transfers (out of) Level 3				(9)	(1)		(208)	(1)
Balance, at the end of the period	6	4	4	8	26		195	216	1,035	920
Balance, at the end of the period											(4,769)	(5,333)
Changes in unrealized gains/ (losses) included in income relating to assets held					5		2	4		13
Changes in unrealized gains/ (losses) included in income relating to liabilities held											(125)	(184)
Changes in unrealized gains/ (losses) included in income relating to assets held-other revenue									(34)	12
Changes in unrealized gains/ (losses) included in income relating to assets held-investment income										$ 1