LOANS - Corporate Loans Credit Quality Indicators (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Loans receivable
Loans, net of unearned income	$ 638,435	$ 617,617
Loans at fair value	3,970	5,005
Corporate
Loans receivable
Loans, net of unearned income	309,733	291,832
Total non-accrual	2,415	1,596
Loans at fair value	3,939	4,971
Corporate \| Commercial and industrial
Loans receivable
Loans, net of unearned income	131,683	119,627
Total non-accrual	1,940	1,071
Corporate \| Financial institutions
Loans receivable
Loans, net of unearned income	62,472	64,317
Total non-accrual	189	173
Corporate \| Mortgage and real estate
Loans receivable
Loans, net of unearned income	46,571	42,471
Total non-accrual	169	232
Corporate \| Lease financing
Loans receivable
Loans, net of unearned income	1,774	2,082
Total non-accrual	58	76
Corporate \| Other
Loans receivable
Loans, net of unearned income	63,294	58,359
Total non-accrual	59	44
Corporate \| Private bank loans managed on a delinquency basis
Loans receivable
Loans, net of unearned income	22,780	20,575
Corporate \| Investment grade
Loans receivable
Loans, net of unearned income	217,331	211,393
Corporate \| Investment grade \| Commercial and industrial
Loans receivable
Loans, net of unearned income	88,871	85,828
Corporate \| Investment grade \| Financial institutions
Loans receivable
Loans, net of unearned income	50,485	53,522
Corporate \| Investment grade \| Mortgage and real estate
Loans receivable
Loans, net of unearned income	21,477	18,869
Corporate \| Investment grade \| Lease financing
Loans receivable
Loans, net of unearned income	1,283	1,725
Corporate \| Investment grade \| Other
Loans receivable
Loans, net of unearned income	55,215	51,449
Corporate \| Non-investment grade
Loans receivable
Loans, net of unearned income	65,683	54,893
Corporate \| Non-investment grade \| Commercial and industrial
Loans receivable
Loans, net of unearned income	40,871	32,726
Total non-accrual	1,940	1,071
Corporate \| Non-investment grade \| Financial institutions
Loans receivable
Loans, net of unearned income	11,799	10,622
Total non-accrual	189	173
Corporate \| Non-investment grade \| Mortgage and real estate
Loans receivable
Loans, net of unearned income	2,145	2,800
Total non-accrual	169	232
Corporate \| Non-investment grade \| Lease financing
Loans receivable
Loans, net of unearned income	434	282
Total non-accrual	58	76
Corporate \| Non-investment grade \| Other
Loans receivable
Loans, net of unearned income	8,019	6,867
Total non-accrual	$ 59	$ 44

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5074-111524

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=6517073

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