DEBT (Revolving Credit Facility) (Details) - USD ($)	1 Months Ended		3 Months Ended		6 Months Ended
	Aug. 31, 2019	Jun. 30, 2015	Sep. 30, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Line of Credit Facility [Line Items]
Long-term Debt					$ 10,633,000,000		$ 7,640,000,000
Letters of credit issued					3,000,000		5,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 2,000,000,000.0	$ 2,000,000,000.0
Line of credit facility, term	5 years	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%
Repayments of Lines of Credit			$ 250,000,000
Revolving Credit Facility | Minimum
Line of Credit Facility [Line Items]
Commitment fee rate	0.07%
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]
Debt Instrument, Reference Rate	0.00%
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%
Revolving Credit Facility | One Month LIBOR | Minimum | Rate 2C
Line of Credit Facility [Line Items]
Debt Instrument, Reference Rate	0.00%
Letter of Credit
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 80,000,000
Swingline Loans
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 100,000,000
0.35% Convertible Senior Notes due June 2020
Line of Credit Facility [Line Items]
Amortization of Debt Discount (Premium)				$ 1,000,000	$ 1,000,000	$ 2,000,000