CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
NET (LOSS) INCOME	$ (144,707)	$ 283,604
OTHER COMPREHENSIVE INCOME (LOSS)
OTHER COMPREHENSIVE INCOME( LOSS)	938	(3,584)
COMPREHENSIVE (LOSS) INCOME	(143,769)	280,020
Less: Comprehensive income attributable to noncontrolling interest	(76)	(7,176)
COMPREHENSIVE (LOSS) INCOME ATTRIBUTABLE TO ARLP	(143,845)	272,844
Defined benefit pension plan
OTHER COMPREHENSIVE INCOME (LOSS)
Amortization of prior service cost	46	47
Amortization of net actuarial gain (loss)	1,064	979
Total adjustments	1,110	1,026
Pneumoconiosis benefits
OTHER COMPREHENSIVE INCOME (LOSS)
Net actuarial loss		(3,465)
Amortization of net actuarial gain (loss)	(172)	(1,145)
Total adjustments	$ (172)	$ (4,610)