LEASES (Components of Nonmineral Lease Expense) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
LEASES [Abstract]
Operating lease cost		$ 56,546
Short-term lease cost	[1]	35,487
Variable lease cost		13,739
Sublease income		(3,108)
Total lease cost		$ 102,664	$ 131,015	$ 110,358

[1] We have elected to recognize the cost of leases with an initial term of one month or less within our short-term lease cost.