DERIVATIVES ACTIVITIES - Credit Derivatives (Details) (USD $)	3 Months Ended
	Mar. 31, 2015 agency counterparty	Dec. 31, 2014
Credit Derivative
Percentage of receivables from counterparties with collateral agreements	98.00%	98.00%
Number of top counterparties which are banks, financial institutions, and other dealers	15
Fair value, Receivable	$ 38,598,000,000	$ 43,796,000,000
Fair Value, Payable	38,923,000,000	43,985,000,000
Notionals, Protection Purchased	1,063,060,000,000	1,116,387,000,000
Notionals, Protection Sold	1,018,742,000,000	1,063,858,000,000
Fair value of derivative in liability position	30,000,000,000	30,000,000,000
Fair value of collateral already posted	28,000,000,000	27,000,000,000
Number of rating agencies	3
Additional collateral to be posted	2,300,000,000
Collateral to be segregated	100,000,000
Aggregate cash obligations and collateral requirements	2,400,000,000
Purchased
Credit Derivative
Fair value, Receivable	13,219,000,000	18,708,000,000
Fair Value, Payable	26,737,000,000	26,527,000,000
Sold
Credit Derivative
Fair value, Receivable	25,379,000,000	25,088,000,000
Fair Value, Payable	12,186,000,000	17,458,000,000
Within 1 year
Credit Derivative
Fair value, Receivable	2,217,000,000	4,356,000,000
Fair Value, Payable	2,066,000,000	4,278,000,000
Notionals, Protection Purchased	213,995,000,000	250,489,000,000
Notionals, Protection Sold	200,970,000,000	229,502,000,000
From 1 to 5 years
Credit Derivative
Fair value, Receivable	31,222,000,000	34,692,000,000
Fair Value, Payable	31,762,000,000	35,160,000,000
Notionals, Protection Purchased	743,158,000,000	790,251,000,000
Notionals, Protection Sold	725,345,000,000	772,001,000,000
After 5 years
Credit Derivative
Fair value, Receivable	5,159,000,000	4,748,000,000
Fair Value, Payable	5,095,000,000	4,547,000,000
Notionals, Protection Purchased	105,907,000,000	75,647,000,000
Notionals, Protection Sold	92,427,000,000	62,355,000,000
Investment Grade
Credit Derivative
Fair value, Receivable	14,717,000,000	17,432,000,000
Fair Value, Payable	14,677,000,000	17,182,000,000
Notionals, Protection Purchased	784,719,000,000	824,831,000,000
Notionals, Protection Sold	756,634,000,000	786,848,000,000
Non-Investment Grade
Credit Derivative
Fair value, Receivable	23,881,000,000	26,364,000,000
Fair Value, Payable	24,246,000,000	26,803,000,000
Notionals, Protection Purchased	278,341,000,000	291,556,000,000
Notionals, Protection Sold	262,108,000,000	277,010,000,000
Credit default swaps and options
Credit Derivative
Fair value, Receivable	38,401,000,000	42,930,000,000
Fair Value, Payable	37,878,000,000	42,201,000,000
Notionals, Protection Purchased	1,045,569,000,000	1,094,199,000,000
Notionals, Protection Sold	1,016,182,000,000	1,054,671,000,000
Total return swaps and other
Credit Derivative
Fair value, Receivable	197,000,000	866,000,000
Fair Value, Payable	1,045,000,000	1,784,000,000
Notionals, Protection Purchased	17,491,000,000	22,188,000,000
Notionals, Protection Sold	2,560,000,000	9,187,000,000
Bank
Credit Derivative
Fair value, Receivable	20,862,000,000	24,828,000,000
Fair Value, Payable	19,370,000,000	23,189,000,000
Notionals, Protection Purchased	548,556,000,000	574,764,000,000
Notionals, Protection Sold	562,737,000,000	604,700,000,000
Broker-dealer
Credit Derivative
Fair value, Receivable	6,872,000,000	8,093,000,000
Fair Value, Payable	7,604,000,000	9,309,000,000
Notionals, Protection Purchased	186,510,000,000	204,542,000,000
Notionals, Protection Sold	186,727,000,000	199,693,000,000
Non-financial
Credit Derivative
Fair value, Receivable	85,000,000	91,000,000
Fair Value, Payable	195,000,000	113,000,000
Notionals, Protection Purchased	4,204,000,000	3,697,000,000
Notionals, Protection Sold	1,405,000,000	1,595,000,000
Insurance and other financial institutions
Credit Derivative
Fair value, Receivable	10,779,000,000	10,784,000,000
Fair Value, Payable	11,754,000,000	11,374,000,000
Notionals, Protection Purchased	323,790,000,000	333,384,000,000
Notionals, Protection Sold	267,873,000,000	257,870,000,000
Interest Rate Swap [Member]
Credit Derivative
Amount derecognized	2,500,000,000
Cash proceeds received for assets derecognized	2,500,000,000
Fair value of derecognized assets	2,600,000,000
Fair value gross derivative assets	157,000,000
Trading derivatives, liability	$ 14,000,000