FAIR VALUE MEASUREMENTS (Details 6) (Level 3, USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Maiden Lane III
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value	6,916
Maiden Lane III | Discounted cash flow
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	10.93%
Corporate debt
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value	685
Corporate debt | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	2.37%
Corporate debt | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	11.08%
Corporate debt | Discounted cash flow | Weighted-average
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	6.73%
Residential mortgage backed securities
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value	12,326
Residential mortgage backed securities | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	4.09%
Constant prepayment rate	0.00%
Loss severity	44.10%
Constant default rate	4.34%
Residential mortgage backed securities | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	11.80%
Constant prepayment rate	16.89%
Loss severity	79.01%
Constant default rate	13.83%
Residential mortgage backed securities | Discounted cash flow | Weighted-average
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	7.95%
Constant prepayment rate	8.02%
Loss severity	61.56%
Constant default rate	9.09%
Certain CDO/ABS | Discounted cash flow
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value	1,961
Certain CDO/ABS | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	2.29%
Constant prepayment rate	0.00%
Loss severity	0.00%
Constant default rate	0.00%
Certain CDO/ABS | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	6.57%
Constant prepayment rate	49.80%
Loss severity	19.46%
Constant default rate	2.29%
Certain CDO/ABS | Discounted cash flow | Weighted-average
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	4.43%
Constant prepayment rate	18.55%
Loss severity	3.22%
Constant default rate	0.38%
CDO/ABS - Direct Investment book | Binomial Expansion Technique (BET)
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value	1,579
CDO/ABS - Direct Investment book | Binomial Expansion Technique (BET) | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Recovery rates	3.00%
Diversity score	5
Weighted average life	1 year 4 months 24 days
CDO/ABS - Direct Investment book | Binomial Expansion Technique (BET) | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Recovery rates	65.00%
Diversity score	75
Weighted average life	9 years 7 months 24 days
CDO/ABS - Direct Investment book | Binomial Expansion Technique (BET) | Weighted-average
Fair Value Inputs Assets Quantitative Information [Line Items]
Recovery rates	33.00%
Diversity score	10
Weighted average life	4 years 7 months 6 days
Commercial mortgage backed securities
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value	2,665
Commercial mortgage backed securities | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	0.00%
Commercial mortgage backed securities | Discounted cash flow | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	24.52%
Commercial mortgage backed securities | Discounted cash flow | Weighted-average
Fair Value Inputs Assets Quantitative Information [Line Items]
Yield	11.58%