FAIR VALUE MEASUREMENT - Valuation Techniques and Inputs for Level 3 Nonrecurring Fair Value Measurements (Details) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	$ (112,000,000)	$ (238,000,000)
Loans held-for-sale
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(2,000,000)	(79,000,000)
Other real estate owned
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(5,000,000)	(17,000,000)
Loans
Nonrecurring fair value changes included in earnings
Nonrecurring fair value measurements included in earnings	(105,000,000)	(142,000,000)
Nonrecurring \| Level 3
Valuation techniques and inputs
Total assets	3,263,000,000	4,003,000,000
Nonrecurring \| Level 3 \| Loans held-for-sale \| Price-based
Valuation techniques and inputs
Total assets	2,413,000,000	3,486,000,000
Nonrecurring \| Level 3 \| Loans held-for-sale \| Price-based \| Minimum
Valuation techniques and inputs
Price	0.00	0.00
Nonrecurring \| Level 3 \| Loans held-for-sale \| Price-based \| Maximum
Valuation techniques and inputs
Price	100.00	100.00
Nonrecurring \| Level 3 \| Loans held-for-sale \| Price-based \| Weighted Average
Valuation techniques and inputs
Price	93.08	81.05
Nonrecurring \| Level 3 \| Discount to price \| Price-based
Valuation techniques and inputs
Total assets		$ 90,000,000
Nonrecurring \| Level 3 \| Other real estate owned \| Price-based
Valuation techniques and inputs
Total assets	59,000,000
Nonrecurring \| Level 3 \| Other real estate owned \| Price-based \| Minimum
Valuation techniques and inputs
Price	$ 64.65
Discount to price (as a percent)	0.34%	0.34%
Appraised Value		$ 0
Nonrecurring \| Level 3 \| Other real estate owned \| Price-based \| Maximum
Valuation techniques and inputs
Price	$ 74.39
Discount to price (as a percent)	13.00%	13.00%
Appraised Value		$ 8,518,230
Nonrecurring \| Level 3 \| Other real estate owned \| Price-based \| Weighted Average
Valuation techniques and inputs
Price	$ 66.21
Discount to price (as a percent)	3.10%	2.86%
Appraised Value		$ 3,813,045
Nonrecurring \| Level 3 \| Appraised value \| Price-based
Valuation techniques and inputs
Total assets		2,000,000
Nonrecurring \| Level 3 \| Loans \| Price-based
Valuation techniques and inputs
Total assets	$ 135,000,000	$ 87,000,000
Nonrecurring \| Level 3 \| Loans \| Price-based \| Minimum
Valuation techniques and inputs
Discount to price (as a percent)	0.25%	13.00%
Appraised Value	$ 25.80
Nonrecurring \| Level 3 \| Loans \| Price-based \| Maximum
Valuation techniques and inputs
Discount to price (as a percent)	13.00%	34.00%
Appraised Value	$ 26,400,000.00
Nonrecurring \| Level 3 \| Loans \| Price-based \| Weighted Average
Valuation techniques and inputs
Discount to price (as a percent)	8.34%	7.99%
Appraised Value	$ 6,462,734.68
Nonrecurring \| Level 3 \| Loans \| Cash flow
Valuation techniques and inputs
Total assets	431,000,000
Nonrecurring \| Level 3 \| Loans \| Cash flow \| Minimum
Valuation techniques and inputs
Price	3.25
Nonrecurring \| Level 3 \| Loans \| Cash flow \| Maximum
Valuation techniques and inputs
Price	105.00
Nonrecurring \| Level 3 \| Loans \| Cash flow \| Weighted Average
Valuation techniques and inputs
Price	59.61
Nonrecurring \| Level 3 \| Loans \| Recovery Analysis
Valuation techniques and inputs
Total assets	197,000,000	$ 157,000,000
Nonrecurring \| Level 3 \| Loans \| Recovery Analysis \| Minimum
Valuation techniques and inputs
Forward price (as a percent)	2.90
Recovery rate (as a percent)		11.79%
Nonrecurring \| Level 3 \| Loans \| Recovery Analysis \| Maximum
Valuation techniques and inputs
Forward price (as a percent)	210.00
Recovery rate (as a percent)		60.00%
Nonrecurring \| Level 3 \| Loans \| Recovery Analysis \| Weighted Average
Valuation techniques and inputs
Forward price (as a percent)	$ 156.78
Recovery rate (as a percent)		23.49%

Fair Value Inputs Appraised Value

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- Definition

Represents the discount to price, used as an input to measure fair value.

+ References

No definition available.

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- Definition

Fair Value Inputs, Forward Price

+ References

No definition available.

+ Details

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- Definition

The price input is a significant unobservable input for certain fixed income instruments. For these instruments, the price input is expressed as a percentage of the notional amount, with a price of $100 meaning that the instrument is valued at par. For most of these instruments, the price varies between zero to $100, or slightly above $100. Relatively illiquid assets that have experienced significant losses since issuance, such as certain asset-backed securities, are at the lower end of the range, whereas most investment grade corporate bonds will fall in the middle to the higher end of the range. For certain structured debt instruments with embedded derivatives, the price input may be above $100 to reflect the embedded features of the instrument (for example, a step-up coupon or a conversion option). The price input is also a significant unobservable input for certain equity securities; however, the range of price inputs varies depending on the nature of the position, the number of shares outstanding and other factors. Because of these factors, the weighted average price input for equity securities does not provide insight regarding the central tendencies of the ranges for equity securities, as equity prices are generally independent of one another and are not subject to a common measurement scale (for example, the zero to $100 range applicable to debt instruments). Prices for loan-held-for-sale and other real estate owned are based on appraised values.

+ References

No definition available.

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Represents the recovery rate, used as an input to measure fair value.

+ References

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- Definition

Amount of gain (loss) recognized in the income statement for an asset measured on a nonrecurring basis using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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