DEBT - Term Note (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2018
Short-term Debt [Line Items]
Repayments of short-term debt	$ 350,000,000	$ 0	$ 0
Notes Payable to Banks
Short-term Debt [Line Items]
Face amount				$ 1,000,000,000.0
Debt instrument, interest rate, effective percentage	3.67%
Repayments of short-term debt	$ 350,000,000
Base Rate | Notes Payable to Banks
Short-term Debt [Line Items]
Basis points spread over LIBOR	1.15%
Federal Funds Effective Swap Rate | Notes Payable to Banks
Short-term Debt [Line Items]
Basis points spread over LIBOR	0.50%
LIBOR | Notes Payable to Banks
Short-term Debt [Line Items]
Basis points spread over LIBOR	1.15%
Maximum | Prime Rate | Notes Payable to Banks
Short-term Debt [Line Items]
Basis points spread over LIBOR	1.00%