REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Royalty income	$ 127,649	$ 62,584	$ 337,619	$ 171,857
Oil income
Disaggregation of Revenue [Line Items]
Royalty income	100,154	53,595	272,450	153,412
Natural gas income
Disaggregation of Revenue [Line Items]
Royalty income	12,074	3,331	30,651	4,909
Natural gas liquids income
Disaggregation of Revenue [Line Items]
Royalty income	$ 15,421	$ 5,658	$ 34,518	$ 13,536