DERIVATIVES (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Aggregate notional amount of interest rate swaps	$ 725,000,000	$ 825,000,000
Fair Value Hedging
Derivative [Line Items]
Aggregate notional amount of interest rate swaps	725,000,000
Face value of medium-term notes	(6,000,000)	$ 10,000,000
Cash Flow Hedging
Derivative [Line Items]
Aggregate notional amount of interest rate swaps	215,000,000
Face value of medium-term notes	$ (2,000,000)