DEBT (Narrative) (Details)		1 Months Ended			3 Months Ended	12 Months Ended
		Mar. 31, 2018 USD ($)	Feb. 28, 2018 USD ($)	Jan. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Discounts and debt issuance costs						$ 4,983,000	$ 5,161,000
Total long-term debt - face value						2,846,373,000	2,846,396,000
Repayments of long term debt						23,000	892,055,000	$ 1,463,308,000
Net proceeds			$ 846,029,000
Net noncash expense								7,257,000
Net noncash expense					$ 466,000
Premium for repayments of debt					5,608,000			139,187,000
Transaction costs for repayments of debt					1,314,000			1,586,000
Combined charge, component of interest expense							7,388,000	148,030,000
Proceeds from issuance of long-term debt						$ 0	850,000,000	$ 2,200,000,000
Term Loan Due 2018 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value							350,000,000
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]
Maximum borrowing capacity						$ 750,000,000
Commitment fee						0.15%
Available borrowing capacity						$ 697,400,000
Borrowings						$ 0
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						$ 52,600,000
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] | Line of Credit [Member]
Debt Instrument [Line Items]
Debt to EBITDA ratio						3.5
Commitment fee						0.25%
Maximum [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate						1.75%
Maximum [Member] | Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate						0.75%
Minimum [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
EBITDA to net cash interest expense ratio						3.0
Commitment fee						0.10%
Minimum [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate						1.00%
Minimum [Member] | Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate						0.00%
Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value						$ 2,846,373,000
Notes [Member] | Term Loan Due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value							250,000,000
Notes [Member] | Investment-Grade Type Covenants Governed [Member]
Debt Instrument [Line Items]
Total long-term debt - face value						$ 2,846,188,000
Notes [Member] | 7.50% notes due 2021 [Member]
Debt Instrument [Line Items]
Maturity year						2021
Repayments of long term debt				$ 40,719,000
Face value				$ 35,111,000
Interest rate				7.50%
Net noncash expense				$ 263,000
Premium for repayments of debt				$ 5,608,000
Notes [Member] | 4.70% notes due 2048 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value						$ 460,949,000	$ 460,949,000
Maturity year						2048
Face value			$ 350,000,000
Interest rate			4.70%			4.70%	4.70%
Net noncash expense			$ 203,000
Premium for repayments of debt		$ 38,164,000
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
Face value			$ 500,000,000
Notes [Member] | 7.15% notes due 2037 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		240,188,000			$ 240,188,000	$ 129,239,000	129,239,000
Maturity year						2037
Repayments of long term debt		$ 110,949,000
Interest rate		7.15%			7.15%	7.15%
Transaction costs for repayments of debt		$ 1,314,000
Notes [Member] | 3.90% notes due 2027 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value						$ 400,000,000	400,000,000
Maturity year						2027
Interest rate						3.90%
Notes [Member] | Floating-Rate Notes Due 2020 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[1]					$ 250,000,000	250,000,000
Maturity year						2020
Notes [Member] | 4.50% notes due 2047 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value						$ 700,000,000	700,000,000
Maturity year						2047
Interest rate						4.50%
Line of Credit [Member]
Debt Instrument [Line Items]
Total long-term debt - face value							$ 250,000,000

[1] This debt is classified as long-term since we intend to refinance it, and we have the ability to do so by borrowing on our line of credit.