DEBT (Revolving Credit Facility) (Details) - USD ($)		6 Months Ended
	Jun. 19, 2015	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Line of Credit Facility [Line Items]
Proceeds from revolving credit facility and short-term borrowings		$ 437,000,000	$ 3,000,000
Letters of credit issued		5,000,000		$ 5,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 2,000,000,000.0
Line of credit facility, term	5 years
Line of credit, current		0		$ 0
Proceeds from revolving credit facility and short-term borrowings		$ 400,000,000
Weighted average interest rate		3.50%
Revolving Credit Facility | Minimum
Line of Credit Facility [Line Items]
Commitment fee rate	0.085%
Revolving Credit Facility | Minimum | Rate 2C
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.00%
Revolving Credit Facility | Maximum
Line of Credit Facility [Line Items]
Commitment fee rate	0.20%
Revolving Credit Facility | Maximum | Rate 2C
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.50%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum | Rate 1
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.875%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum | Rate 1
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.50%
Revolving Credit Facility | Federal Funds Purchased | Rate 2B
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.50%
Revolving Credit Facility | One Month LIBOR | Rate 2C
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.00%
Letter of Credit
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 70,000,000
Swingline Loans
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 50,000,000