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FAIR VALUE MEASUREMENTS - Assets and Liabilities on Recurring Basis (Detail) - USD ($) $ in Millions | Jun. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | $ 3,279 | $ 3,341
Loans held for sale | [1] | 39 | 14
Derivative assets |  | 149 | 43
Derivative liabilities |  | 27 | 39
US Government Agencies [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 172 | 187
U.S. Government-Sponsored Entities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 301 | 313
Agency Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 1,242 | 1,161
Commercial Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 232 | 228
States of the U.S. and Political Subdivisions [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 15 | 21
Other Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 2 | 2
Level 1 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Derivative assets |  | 0 | 0
Derivative liabilities |  | 0 | 0
Level 2 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 3,279 | 3,341
Derivative assets |  | 146 | 42
Derivative liabilities |  | 27 | 39
Level 3 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Derivative assets |  | 3 | 1
Derivative liabilities |  | 0 | 0
Fair Value, Recurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 3,279 | 3,341
Loans held for sale |  | 39 | 14
Derivative assets |  | 149 | 43
Assets measured at fair value on a recurring basis, Total |  | 3,467 | 3,398
Derivative liabilities |  | 27 | 39
Liabilities measured at fair value on a recurring basis, Total |  | 27 | 39
Fair Value, Recurring [Member] | Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 25 | 36
Fair Value, Recurring [Member] | Not for Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 2 | 3
Fair Value, Recurring [Member] | Trading Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 145 | 43
Fair Value, Recurring [Member] | Non Trading Account Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 4 |
Fair Value, Recurring [Member] | US Government Agencies [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 172 | 187
Fair Value, Recurring [Member] | U.S. Government-Sponsored Entities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 301 | 313
Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 1,315 | 1,429
Fair Value, Recurring [Member] | Agency Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 1,242 | 1,161
Fair Value, Recurring [Member] | Commercial Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 232 | 228
Fair Value, Recurring [Member] | States of the U.S. and Political Subdivisions [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 15 | 21
Fair Value, Recurring [Member] | Other Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 2 | 2
Fair Value, Recurring [Member] | Level 1 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Loans held for sale |  | 0 | 0
Derivative assets |  | 0 | 0
Assets measured at fair value on a recurring basis, Total |  | 0 | 0
Derivative liabilities |  | 0 | 0
Liabilities measured at fair value on a recurring basis, Total |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Not for Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Non Trading Account Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 0 |
Fair Value, Recurring [Member] | Level 1 [Member] | US Government Agencies [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | U.S. Government-Sponsored Entities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Agency Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Agency Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Commercial Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | States of the U.S. and Political Subdivisions [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 1 [Member] | Other Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 2 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 3,279 | 3,341
Loans held for sale |  | 39 | 14
Derivative assets |  | 146 | 42
Assets measured at fair value on a recurring basis, Total |  | 3,464 | 3,397
Derivative liabilities |  | 27 | 39
Liabilities measured at fair value on a recurring basis, Total |  | 27 | 39
Fair Value, Recurring [Member] | Level 2 [Member] | Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 25 | 36
Fair Value, Recurring [Member] | Level 2 [Member] | Not for Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 2 | 3
Fair Value, Recurring [Member] | Level 2 [Member] | Trading Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 145 | 42
Fair Value, Recurring [Member] | Level 2 [Member] | Non Trading Account Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 1 |
Fair Value, Recurring [Member] | Level 2 [Member] | US Government Agencies [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 172 | 187
Fair Value, Recurring [Member] | Level 2 [Member] | U.S. Government-Sponsored Entities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 301 | 313
Fair Value, Recurring [Member] | Level 2 [Member] | Agency Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 1,315 | 1,429
Fair Value, Recurring [Member] | Level 2 [Member] | Agency Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 1,242 | 1,161
Fair Value, Recurring [Member] | Level 2 [Member] | Commercial Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 232 | 228
Fair Value, Recurring [Member] | Level 2 [Member] | States of the U.S. and Political Subdivisions [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 15 | 21
Fair Value, Recurring [Member] | Level 2 [Member] | Other Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 2 | 2
Fair Value, Recurring [Member] | Level 3 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Loans held for sale |  | 0 | 0
Derivative assets |  | 3 | 1
Assets measured at fair value on a recurring basis, Total |  | 3 | 1
Derivative liabilities |  | 0 | 0
Liabilities measured at fair value on a recurring basis, Total |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Not for Trading Liabilities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative liabilities |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 0 | 1
Fair Value, Recurring [Member] | Level 3 [Member] | Non Trading Account Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Derivative assets |  | 3 |
Fair Value, Recurring [Member] | Level 3 [Member] | US Government Agencies [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | U.S. Government-Sponsored Entities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Agency Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Agency Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Commercial Mortgage-Backed Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | States of the U.S. and Political Subdivisions [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | 0 | 0
Fair Value, Recurring [Member] | Level 3 [Member] | Other Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt securities available for sale |  | $ 0 | $ 0
[1] | Amount represents loans for which we have elected the fair value option. See Note 17.

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