DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Effect of Cash Flow Hedging on Income Statement (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative [Line Items]
Interest Income - Loans and Leases	$ 221,000,000	$ 221,000,000
Interest Expense - Short-Term Borrowings	6,000,000	7,000,000
Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income	0	0
Interest Income - Loans and Leases | Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income	2,000,000	0
Interest Expense - Short-Term Borrowings | Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income	$ (4,000,000)	$ (5,000,000)