Revenue Recognition (Tables)

6 Months Ended

Jun. 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 June 30, 2019
North America revenues	$	210,149	$	54,896	$	47,885	$	623	$	313,553
Seaborne revenues	—		206,349		50,320		—		256,669
Total revenues	$	210,149	$	261,245	$	98,205	$	623	$	570,222
Three Months Ended June 30, 2018
North America revenues	$	229,035	$	38,323	$	40,547	$	3,625	$	311,530
Seaborne revenues	843		220,709		59,267		—		280,819
Total revenues	$	229,878	$	259,032	$	99,814	$	3,625	$	592,349
Six Months Ended June 30, 2019
North America revenues	$	422,878	$	99,562	$	94,414	$	3,837	$	620,691
Seaborne revenues	—		414,945		89,769		—		504,714
Total revenues	$	422,878	$	514,507	$	184,183	$	3,837	$	1,125,405
Six Months Ended June 30, 2018
North America revenues	$	473,395	$	68,001	$	84,214	$	3,625	$	629,235
Seaborne revenues	1,911		429,378		107,120		—		538,409
Total revenues	$	475,306	$	497,379	$	191,334	$	3,625	$	1,167,644