Revenue Recognition (Tables)

9 Months Ended

Sep. 30, 2018

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, 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
Three Months Ended September 30, 2017
North America revenues	$	276,000	$	84,411	$	76,426	$	4,733	$	441,570
Seaborne revenues	—		154,535		17,433		—		171,968
Total revenues	$	276,000	$	238,946	$	93,859	$	4,733	$	613,538

	PRB		MET		Other Thermal		Corporate, Other and Eliminations		Consolidated
	(in thousands)
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
Nine Months Ended September 30, 2017
North America revenues	$	780,007	$	235,644	$	216,929	$	4,790	$	1,237,370
Seaborne revenues	—		456,534		70,475		—		527,009
Total revenues	$	780,007	$	692,178	$	287,404	$	4,790	$	1,764,379