REGULATORY MATTERS - Capital and Capital Ratio Information (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Total Capital to Risk-Weighted Assets (Amount)
Actual	$ 16,781us-gaap_Capital	$ 15,885us-gaap_Capital
Minimum Capital Adequacy	8,477	7,891
Classification as Well Capitalized	10,596	9,863
Total Capital to Risk-Weighted Assets (Ratio)
Actual	15.80%us-gaap_CapitalToRiskWeightedAssets	16.10%us-gaap_CapitalToRiskWeightedAssets
Minimum Capital Adequacy	8.00%	8.00%
Classification as Well Capitalized	10.00%	10.00%
Tier 1 Capital to Risk-Weighted Assets (Amount)
Actual	13,173us-gaap_TierOneRiskBasedCapital	13,301us-gaap_TierOneRiskBasedCapital
Minimum Capital Adequacy	4,239	3,945
Classification as Well Capitalized	6,358	5,918
Tier 1 Capital to Risk-Weighted Assets (Ratio)
Actual	12.40%	13.50%
Minimum Capital Adequacy	4.00%	4.00%
Classification as Well Capitalized	6.00%	6.00%
Tier 1 Capital to Average Assets (Leverage) (Amount)
Actual	13,173us-gaap_TierOneLeverageCapital	13,301us-gaap_TierOneLeverageCapital
Minimum Capital Adequacy	4,982	4,577
Classification as Well Capitalized	$ 6,227	$ 5,721
Tier 1 Capital to Average Assets (Leverage) (Ratio)
Actual	10.60%	11.60%
Minimum Capital Adequacy	4.00%	4.00%
Classification as Well Capitalized	5.00%	5.00%

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The amount of total capital as defined in the regulations.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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