DEBT (Debt) (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
		May 31, 2020	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Total short-term debt			$ 0	$ 0	$ 0
Total long-term debt - face value			2,857,465	3,357,899	2,846,367
Unamortized discounts and debt issuance costs			(69,128)	(70,224)	(60,776)
Total long-term debt - book value			2,788,337	3,287,675	2,785,591
Less current maturities			15,436	515,435	25
Total long-term debt - reported value			2,772,901	2,772,240	2,785,566
Estimated fair value of long-term debt			3,219,828	3,443,225	2,926,140
Line of Credit [Member] | Bank Line Of Credit Due 2025 [Member]
Debt Instrument [Line Items]
Total short-term debt	[1]		$ 0	0	0
Maturity year	[1]		2025
Line of Credit [Member] | Bank Line Of Credit Due 2025 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[1]		$ 0	0	0
Maturity year	[1]		2025
Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 2,857,465
Notes [Member] | Floating-Rate Notes Due 2020 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 250,000	$ 0	0	250,000
Maturity year			2020
Notes [Member] | Floating-Rate Notes Due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 0	500,000	500,000
Maturity year			2021
Notes [Member] | 8.85% notes due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 6,000	6,000	6,000
Interest rate			8.85%
Maturity year			2021
Effective interest rate			8.88%
Notes [Member] | 4.50% notes due 2025 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 400,000	400,000	400,000
Interest rate			4.50%
Maturity year			2025
Effective interest rate			4.65%
Notes [Member] | 3.90% notes due 2027 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 400,000	400,000	400,000
Interest rate			3.90%
Maturity year			2027
Effective interest rate			4.00%
Notes [Member] | 3.50% notes due 2030 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 750,000	$ 750,000	750,000	0
Interest rate		3.50%	3.50%
Maturity year		2030	2030
Effective interest rate			3.94%
Notes [Member] | 7.15% notes due 2037 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 129,239	129,239	129,239
Interest rate			7.15%
Maturity year			2037
Effective interest rate			8.05%
Notes [Member] | 4.50% notes due 2047 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 700,000	700,000	700,000
Interest rate			4.50%
Maturity year			2047
Effective interest rate			4.59%
Notes [Member] | 4.70% notes due 2048 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 460,949	460,949	460,949
Interest rate			4.70%
Maturity year			2048
Effective interest rate			5.42%
Other Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value			$ 11,277	$ 11,711	$ 179
Effective interest rate			0.88%
Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 1,000,000

[1] Borrowings on the bank line of credit are classified as short-term if we intend to repay within twelve months and as long-term if we have the intent and ability to extend payment beyond twelve months.