DEBT (Narrative) (Details)	1 Months Ended		3 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($)	May 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Apr. 30, 2020 USD ($)
Debt Instrument [Line Items]
Discounts and debt issuance costs					$ 7,203,000	$ 4,983,000
Total long-term debt - face value					3,357,899,000	2,846,373,000
Net proceeds		$ 741,417,000
Net noncash expense							$ 466,000
Repayment of long-term debt					250,025,000	23,000	892,055,000
Premium for repayments of debt							5,608,000
Transaction costs for repayments of debt							1,314,000
Combined charge, component of interest expense							7,388,000
Short-term debt					0	0
Proceeds from issuance of long-term debt					$ 750,000,000	0	$ 850,000,000
Term Loan Due April 2021 [Member] | Term Loan Due [Member]
Debt Instrument [Line Items]
Available borrowing capacity	$ 500,000,000			$ 500,000,000
Repayments of debt				$ 250,000,000
Investment-Grade Type Covenants Governed [Member]
Debt Instrument [Line Items]
Number of indentures with customary investment-grade type covenants | item					3
Line of Credit [Member]
Debt Instrument [Line Items]
Transaction fees			$ 4,632,000
Maximum borrowing capacity			$ 1,000,000,000		$ 1,000,000,000
Commitment fee					0.15%
Available borrowing capacity					$ 943,920,000
Borrowings					$ 0
Debt issued, term			5 years
Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					1.25%
Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					0.25%
Line of Credit [Member] | Maximum, Upon Certain Acquisitions [Member]
Debt Instrument [Line Items]
Debt to EBITDA ratio					3.75
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Outstanding standby letters of credit					$ 56,080,000
Period of standby letters of credit					1 year
Standby Letters of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					0.175%
Maximum [Member] | Term Loan Due April 2021 [Member] | Term Loan Due [Member]
Debt Instrument [Line Items]
Short-term debt								$ 750,000,000
Maximum [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Debt to EBITDA ratio					3.50
Commitment fee					0.275%
Maximum [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					1.875%
Maximum [Member] | Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					0.875%
Minimum [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Commitment fee					0.125%
Minimum [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					1.125%
Minimum [Member] | Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate					0.125%
Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value					$ 3,357,899,000
Notes [Member] | Investment-Grade Type Covenants Governed [Member]
Debt Instrument [Line Items]
Total long-term debt - face value					3,346,188,000
Notes [Member] | 3.50% notes due 2030 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 750,000,000			$ 750,000,000	0
Maturity year		2030			2030
Interest rate		3.50%			3.50%
Notes [Member] | Floating-Rate Notes Due 2020 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 250,000,000			$ 0	250,000,000
Maturity year					2020
Repayment of long-term debt	$ 250,000,000
Notes [Member] | Floating-Rate Notes Due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value					$ 500,000,000	$ 500,000,000
Maturity year					2021