Consolidated Investment Entities (Details 3) (Consolidated Investment Entities:, USD $)				3 Months Ended				3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Other assets	Mar. 31, 2012 Other assets Maximum Discounted cash flow valuation technique	Mar. 31, 2012 Other assets Minimum Discounted cash flow valuation technique	Mar. 31, 2012 Other assets Weighted Average Discounted cash flow valuation technique	Mar. 31, 2012 Debt	Mar. 31, 2012 Debt Maximum Discounted cash flow valuation technique	Mar. 31, 2012 Debt Minimum Discounted cash flow valuation technique	Mar. 31, 2012 Debt Weighted Average Discounted cash flow valuation technique
Summary of the significant unobservable inputs
Other assets			$ 1,035,000,000
Debt	4,769,000,000	4,712,000,000					4,769,000,000
Expected rental value (per square foot)				$ 1,281	$ 2	$ 34
Annual default rate								4.50%	2.50%	2.80%
Discount rate (as a percent)								45.00%	2.30%	3.80%
Equivalent yield (as a percent)				10.70%	3.10%	6.60%
Constant prepayment rate (as a percent)								10.00%	5.00%	9.60%
Loss severity (as a percent)								63.60%	36.40%	61.90%