COMMON UNIT-BASED COMPENSATION PLANS - LTIP Grants (Details) - ARLP LTIP - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Number of units
Balance at the beginning of the period (in units)	2,710,344
Granted (in units)	455,574
Vested (in units)	(1,582,422)
Forfeited (in units)	(22,958)
Balance at the end of the period (in units)	1,560,538
Weighted average grant date fair value per unit
Balance at the beginning of the period (in dollars per unit)	$ 10.91
Granted (in dollars per unit)	19.69
Vested (in dollars per unit)	6.53
Forfeited (in dollars per unit)	15.31
Balance at the end of the period (in dollars per unit)	$ 17.86
Intrinsic value (in dollars)
Intrinsic value of outstanding grants (in dollars)	$ 31,289	$ 51,405
Other information
Common units issued	936,544