Revenue Recognition (Tables)

9 Months Ended

Sep. 30, 2019

Revenue from Contract with Customer [Abstract]

Schedule of effects of revenue recognition

	PRB		MET		Other Thermal		Corporate, Other and Eliminations		Consolidated
	(in thousands)
Three Months Ended September 30, 2019
North America revenues	$	269,967	$	63,755	$	47,571	$	955	$	382,248
Seaborne revenues	—		190,738		46,481		—		237,219
Total revenues	$	269,967	$	254,493	$	94,052	$	955	$	619,467
Three Months Ended September 30, 2018
North America revenues	$	261,927	$	49,698	$	56,051	$	4,262	$	371,938
Seaborne revenues	—		186,630		74,612		—		261,242
Total revenues	$	261,927	$	236,328	$	130,663	$	4,262	$	633,180
Nine Months Ended September 30, 2019
North America revenues	$	692,845	$	163,317	$	141,985	$	4,792	$	1,002,939
Seaborne revenues	—		605,683		136,250		—		741,933
Total revenues	$	692,845	$	769,000	$	278,235	$	4,792	$	1,744,872
Nine Months Ended September 30, 2018
North America revenues	$	735,322	$	117,699	$	140,265	$	7,887	$	1,001,173
Seaborne revenues	1,911		616,008		181,732		—		799,651
Total revenues	$	737,233	$	733,707	$	321,997	$	7,887	$	1,800,824