DEBT (Credit Facilities) (Details) - USD ($)	3 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 03, 2019
Line of Credit Facility [Line Items]
2019 Term Loan	$ 0	$ 375,000,000.0			$ 850,000,000.0
Cash and cash equivalents	1,963,200,000	1,320,800,000	$ 557,000,000.0	$ 337,500,000
Revolving Credit Facility, maximum borrowing capacity	1,000,000,000.0
Notes Payable	1,800,000	2,100,000
Credit Facility, Maximum Swing Line Borrowings	100,000,000.0
Notes Payable	5,500,000	6,100,000
Senior notes due 2022 [Member]
Line of Credit Facility [Line Items]
Senior Notes, Noncurrent	0	$ 500,000,000.0
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	1,000,000,000.0
Credit Facility, Maximum Letters of Credit	$ 150,000,000.0
Line of Credit Facility, Interest Rate at Period End	1.10%
Third Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Credit Facility Option to Increase	$ 500,000,000.0
Prime Rate [Member] | Third Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.100% to 0.225%