INCOME TAXES (Sources and Tax Effects of Differences Between Benefit from Income Taxes and Amount Computed by Applying Federal Statutory Income Tax Rate to Losses from Continuing Operations before Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES [Abstract]
Income tax expense at the federal statutory tax rate	$ 156,198	$ 159,117	$ 130,891
Statutory depletion	(24,728)	(23,006)	(21,733)
State and local income taxes, net of federal income tax benefit	27,352	26,119	18,562
Share-based compensation	(6,877)	(17,277)	(16,551)
Uncertain tax positions	1,380	1,822	(6,402)
Transition tax	0	0	595
Research and development credit	(2,650)	(9,490)	0
Other, net	5,128	(2,087)	87
Total income tax expense	$ 155,803	$ 135,198	$ 105,449
Income tax expense at the federal statutory tax rate	21.00%	21.00%	21.00%
Statutory depletion, Rate	(3.30%)	(3.00%)	(3.50%)
State and local income taxes, net of federal income tax benefit, Rate	3.70%	3.40%	3.00%
Share-based compensation, Rate	(0.90%)	(2.30%)	(2.70%)
Uncertain tax positions, Rate	0.20%	0.20%	(1.00%)
Transition tax, Rate	0.00%	0.00%	0.10%
Research and development credit, Rate	(0.40%)	(1.30%)	0.00%
Other, net, Rate	0.60%	(0.20%)	0.00%
Effective tax rate	20.90%	17.80%	16.90%