ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Recorded Investment in Retail Loans by Delinquency Status (Details) (Loans and Leases, USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 90,749	$ 85,859
Residential, including originated home equity products
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	28,852	27,912
1-29 Days Past Due	811	861
30-89 Days Past Due	227	259
90 Days or More Past Due	568	662
Total	30,458	29,694
Home equity products serviced by others
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,638	1,901
1-29 Days Past Due	138	167
30-89 Days Past Due	42	43
90 Days or More Past Due	52	60
Total	1,870	2,171
Other secured retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	12,438	10,068
1-29 Days Past Due	673	550
30-89 Days Past Due	79	66
90 Days or More Past Due	16	16
Total	13,206	10,700
Unsecured retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,548	3,593
1-29 Days Past Due	118	185
30-89 Days Past Due	49	67
90 Days or More Past Due	30	54
Total	3,745	3,899
Total retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	46,476	43,474
1-29 Days Past Due	1,740	1,763
30-89 Days Past Due	397	435
90 Days or More Past Due	666	792
Total	$ 49,279	$ 46,464