LOANS (Details 2) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Loans receivable
Loans, net of unearned income	$ 646,364,000,000	$ 655,464,000,000
Loans at fair value	4,988,000,000	5,287,000,000
Residential First Mortgage Loans | Loan to Values (LTVs)
Residential Mortgage Loan to Values
Loan, credit indicator ratio less than or equal to 80%	41,377,000,000	41,555,000,000
Loan, credit indicator ratio greater than 80% but less than or equal to 100%	17,908,000,000	19,070,000,000
Loan, credit indicator ratio greater than 100%	12,797,000,000	14,995,000,000
Residential First Mortgage Loans | Consumer Credit Scores (FICOs)
Consumer Loans Credit Quality Indicators, FICO score
Loan, credit score less than 620	15,035,000,000	16,754,000,000
Loan, credit score equal to or greater than 620 but less than 660	7,445,000,000	8,013,000,000
Loan, credit score equal to or greater than 660	49,731,000,000	50,833,000,000
Home equity loans | Loan to Values (LTVs)
Residential Mortgage Loan to Values
Loan, credit indicator ratio less than or equal to 80%	12,050,000,000	12,611,000,000
Loan, credit indicator ratio greater than 80% but less than or equal to 100%	8,897,000,000	9,529,000,000
Loan, credit indicator ratio greater than 100%	12,373,000,000	13,153,000,000
Home equity loans | Consumer Credit Scores (FICOs)
Consumer Loans Credit Quality Indicators, FICO score
Loan, credit score less than 620	4,929,000,000	5,439,000,000
Loan, credit score equal to or greater than 620 but less than 660	3,104,000,000	3,208,000,000
Loan, credit score equal to or greater than 660	25,847,000,000	26,820,000,000
Credit cards | Consumer Credit Scores (FICOs)
Consumer Loans Credit Quality Indicators, FICO score
Loan, credit score less than 620	7,608,000,000	7,833,000,000
Loan, credit score equal to or greater than 620 but less than 660	9,928,000,000	10,304,000,000
Loan, credit score equal to or greater than 660	83,619,000,000	90,248,000,000
Installment and other | Consumer Credit Scores (FICOs)
Consumer Loans Credit Quality Indicators, FICO score
Loan, credit score less than 620	3,803,000,000	4,414,000,000
Loan, credit score equal to or greater than 620 but less than 660	2,249,000,000	2,417,000,000
Loan, credit score equal to or greater than 660	5,118,000,000	5,365,000,000
Consumer
Loans receivable
Recorded investment in loans	376,094,000,000	387,194,000,000
Loans, 30-89 days past due	6,814,000,000	7,755,000,000
Loans, greater than or equal to 90 days past due	6,644,000,000	7,722,000,000
Loans, Past due Government guaranteed	5,624,000,000	6,000,000,000
Loans, net of unearned income	395,176,000,000	408,671,000,000
Loans, total non-accrual	8,149,000,000	9,196,000,000
Loans, 90 days past due and accruing	6,341,000,000	6,749,000,000
Loans less than this number of days past due are considered current	30 days	30 days
Loans at fair value	1,202,000,000	1,231,000,000
Consumer | Minimum
Residential Mortgage Loan to Values
Minimum number of payments made consecutively for the loans to be re-aged	1	1
Consumer | Maximum
Residential Mortgage Loan to Values
Minimum number of payments made consecutively for the loans to be re-aged	3	3
Consumer | Loan to Values (LTVs)
Residential Mortgage Loan to Values
Loan, credit indicator ratio less than or equal to 80%	53,427,000,000	54,166,000,000
Loan, credit indicator ratio greater than 80% but less than or equal to 100%	26,805,000,000	28,599,000,000
Loan, credit indicator ratio greater than 100%	25,170,000,000	28,148,000,000
Consumer | Consumer Credit Scores (FICOs)
Consumer Loans Credit Quality Indicators, FICO score
Loan, credit score less than 620	31,375,000,000	34,440,000,000
Loan, credit score equal to or greater than 620 but less than 660	22,726,000,000	23,942,000,000
Loan, credit score equal to or greater than 660	164,315,000,000	173,266,000,000
Consumer | Residential First Mortgage Loans
Loans receivable
Loans at fair value	1,200,000,000	1,200,000,000
Delinquency status
Number of days past due, non-accrual status	90 days	90 days
Consumer | Home equity loans
Delinquency status
Number of days past due, non-accrual status	90 days	90 days
Consumer | Credit cards
Delinquency status
Number of days past due, non-accrual status	180 days	180 days
Consumer | Installment and other
Delinquency status
Number of days past due, non-accrual status	90 days	90 days
Consumer | Commercial market loans
Delinquency status
Number of days past due, non-accrual status	90 days	90 days
Consumer | Special Asset Pool (SAP)
Loans receivable
Recorded investment in loans	504,000,000	545,000,000
Loans, 30-89 days past due	18,000,000	18,000,000
Loans, greater than or equal to 90 days past due	25,000,000	29,000,000
Loans, net of unearned income	547,000,000	592,000,000
Loans, total non-accrual	75,000,000	81,000,000
Consumer | Total GCB and LCL
Loans receivable
Recorded investment in loans	375,590,000,000	386,649,000,000
Loans, 30-89 days past due	6,796,000,000	7,737,000,000
Loans, greater than or equal to 90 days past due	6,619,000,000	7,693,000,000
Loans, Past due Government guaranteed	5,624,000,000	6,000,000,000
Loans, net of unearned income	394,629,000,000	408,079,000,000
Loans, total non-accrual	8,074,000,000	9,115,000,000
Loans, 90 days past due and accruing	6,341,000,000	6,749,000,000
Consumer | Unsecured Revolving Loans
Delinquency status
Number of days past due, non-accrual status	180 days	180 days
Consumer | In North America Offices
Loans receivable
Recorded investment in loans	230,638,000,000	241,616,000,000
Loans, 30-89 days past due	4,711,000,000	5,618,000,000
Loans, greater than or equal to 90 days past due	5,074,000,000	6,053,000,000
Loans, Past due Government guaranteed	5,624,000,000	6,000,000,000
Loans, net of unearned income	246,047,000,000	259,287,000,000
Loans, total non-accrual	6,137,000,000	7,108,000,000
Loans, 90 days past due and accruing	5,874,000,000	6,241,000,000
Consumer | In North America Offices | Residential First Mortgage Loans
Loans receivable
Recorded investment in loans	73,495,000,000	75,791,000,000
Loans, 30-89 days past due	2,567,000,000	3,074,000,000
Loans, greater than or equal to 90 days past due	2,667,000,000	3,339,000,000
Loans, Past due Government guaranteed	5,624,000,000	6,000,000,000
Loans, net of unearned income	84,353,000,000	88,204,000,000
Loans, total non-accrual	4,098,000,000	4,922,000,000
Loans, 90 days past due and accruing	4,465,000,000	4,695,000,000
Loans, 30-89 days past due, guaranteed by U.S. government-sponsored agencies	1,200,000,000	1,300,000,000
Loans, greater than or equal to 90 days past due, guaranteed by U.S. government-sponsored agencies	4,400,000,000	4,700,000,000
Consumer | In North America Offices | Home equity loans
Loans receivable
Recorded investment in loans	34,329,000,000	35,740,000,000
Loans, 30-89 days past due	528,000,000	642,000,000
Loans, greater than or equal to 90 days past due	742,000,000	843,000,000
Loans, net of unearned income	35,599,000,000	37,225,000,000
Loans, total non-accrual	1,626,000,000	1,797,000,000
Consumer | In North America Offices | Credit cards
Loans receivable
Recorded investment in loans	102,339,000,000	108,892,000,000
Loans, 30-89 days past due	1,378,000,000	1,582,000,000
Loans, greater than or equal to 90 days past due	1,395,000,000	1,527,000,000
Loans, net of unearned income	105,112,000,000	112,001,000,000
Loans, 90 days past due and accruing	1,395,000,000	1,527,000,000
Consumer | In North America Offices | Installment and other
Loans receivable
Recorded investment in loans	12,360,000,000	13,319,000,000
Loans, 30-89 days past due	195,000,000	288,000,000
Loans, greater than or equal to 90 days past due	248,000,000	325,000,000
Loans, net of unearned income	12,803,000,000	13,932,000,000
Loans, total non-accrual	252,000,000	179,000,000
Loans, 90 days past due and accruing	5,000,000	8,000,000
Consumer | In North America Offices | Commercial market loans
Loans receivable
Recorded investment in loans	8,115,000,000	7,874,000,000
Loans, 30-89 days past due	43,000,000	32,000,000
Loans, greater than or equal to 90 days past due	22,000,000	19,000,000
Loans, net of unearned income	8,180,000,000	7,925,000,000
Loans, total non-accrual	161,000,000	210,000,000
Loans, 90 days past due and accruing	9,000,000	11,000,000
Consumer | In offices outside North America
Loans receivable
Recorded investment in loans	144,952,000,000	145,033,000,000
Loans, 30-89 days past due	2,085,000,000	2,119,000,000
Loans, greater than or equal to 90 days past due	1,545,000,000	1,640,000,000
Loans, net of unearned income	148,582,000,000	148,792,000,000
Loans, total non-accrual	1,937,000,000	2,007,000,000
Loans, 90 days past due and accruing	467,000,000	508,000,000
Consumer | In offices outside North America | Residential First Mortgage Loans
Loans receivable
Recorded investment in loans	45,371,000,000	45,496,000,000
Loans, 30-89 days past due	567,000,000	547,000,000
Loans, greater than or equal to 90 days past due	449,000,000	485,000,000
Loans, net of unearned income	46,387,000,000	46,528,000,000
Loans, total non-accrual	709,000,000	807,000,000
Consumer | In offices outside North America | Home equity loans
Loans receivable
Recorded investment in loans	3,000,000	4,000,000
Loans, greater than or equal to 90 days past due	2,000,000	2,000,000
Loans, net of unearned income	5,000,000	6,000,000
Loans, total non-accrual	2,000,000	2,000,000
Consumer | In offices outside North America | Credit cards
Loans receivable
Recorded investment in loans	37,653,000,000	38,920,000,000
Loans, 30-89 days past due	949,000,000	970,000,000
Loans, greater than or equal to 90 days past due	774,000,000	805,000,000
Loans, net of unearned income	39,376,000,000	40,695,000,000
Loans, total non-accrual	508,000,000	516,000,000
Loans, 90 days past due and accruing	467,000,000	508,000,000
Consumer | In offices outside North America | Installment and other
Loans receivable
Recorded investment in loans	29,706,000,000	29,350,000,000
Loans, 30-89 days past due	463,000,000	496,000,000
Loans, greater than or equal to 90 days past due	172,000,000	167,000,000
Loans, net of unearned income	30,341,000,000	30,013,000,000
Loans, total non-accrual	241,000,000	254,000,000
Consumer | In offices outside North America | Commercial market loans
Loans receivable
Recorded investment in loans	32,219,000,000	31,263,000,000
Loans, 30-89 days past due	106,000,000	106,000,000
Loans, greater than or equal to 90 days past due	148,000,000	181,000,000
Loans, net of unearned income	32,473,000,000	31,550,000,000
Loans, total non-accrual	$ 477,000,000	$ 428,000,000
Open-ended consumer loans
Residential Mortgage Loan to Values
Minimum number of payments made consecutively for the loans to be re-aged	3	3
Number of re-age modification limitations in twelve months	1	1
Number of re-age modification limitations in five years	2	2