Segment Information (Tables)

9 Months Ended

Sep. 30, 2018

Segment Reporting [Abstract]

Schedule of Operating Segment Results

	PRB		MET		Other Thermal		Corporate, Other and Eliminations			Consolidated
	(in thousands)
Three Months Ended September 30, 2018
Revenues	$	261,927	$	236,328	$	130,663	$	4,262		$	633,180
Adjusted EBITDA	48,646		81,250		25,200		(30,202		)	124,894
Depreciation, depletion and amortization	9,114		18,106		3,924		631			31,775
Accretion on asset retirement obligation	4,885		469		565		1,073			6,992
Total assets	374,092		561,989		127,904		933,637			1,997,622
Capital expenditures	3,458		17,827		3,332		1,076			25,693
Three Months Ended September 30, 2017
Revenues	$	276,000	$	238,946	$	93,859	$	4,733		$	613,538
Adjusted EBITDA	48,768		53,346		21,217		(18,240		)	105,091
Depreciation, depletion and amortization	9,577		18,479		3,465		393			31,914
Accretion on asset retirement obligation	5,040		511		540		1,489			7,580
Total assets	419,162		538,637		130,729		934,005			2,022,533
Capital expenditures	2,047		4,597		4,013		2,924			13,581
Nine Months Ended September 30, 2018
Revenues	$	737,233	$	733,707	$	321,997	$	7,887		$	1,800,824
Adjusted EBITDA	102,639		251,649		52,710		(91,806		)	315,192
Depreciation, depletion and amortization	25,841		53,109		11,459		1,618			92,027
Accretion on asset retirement obligation	14,656		1,406		1,696		3,219			20,977
Total assets	374,092		561,989		127,904		933,637			1,997,622
Capital expenditures	7,221		35,555		7,097		5,869			55,742
Nine Months Ended September 30, 2017
Revenues	$	780,007	$	692,178	$	287,404	$	4,790		$	1,764,379
Adjusted EBITDA	128,562		184,208		75,369		(66,229		)	321,910
Depreciation, depletion and amortization	27,661		55,629		9,950		1,296			94,536
Accretion on asset retirement obligation	15,120		1,568		1,621		4,517			22,826
Total assets	419,162		538,637		130,729		934,005			2,022,533
Capital expenditures	2,997		16,032		6,653		4,821			30,503

Reconciliation Statement of Segment Income from Operations to Consolidated Income Before Income Taxes

A reconciliation of net income to adjusted EBITDA follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(In thousands)
Net income	$	123,192		$	68,351		$	226,483		$	157,179
Benefit from income taxes	(45,215		)	(1,643		)	(49,125		)	(484		)
Interest expense, net	3,378			5,252			10,998			19,311
Depreciation, depletion and amortization	31,775			31,914			92,027			94,536
Accretion on asset retirement obligations	6,992			7,580			20,977			22,826
Amortization of sales contracts, net	3,241			13,861			9,540			42,903
Gain on sale of Lone Mountain Processing, Inc.	—			(21,574		)	—			(21,574		)
Net loss resulting from early retirement of debt and debt restructuring	—			486			485			2,547
Non-service related pension and postretirement benefit costs	971			821			2,206			1,774
Reorganization items, net	560			43			1,601			2,892
Adjusted EBITDA	$	124,894		$	105,091		$	315,192		$	321,910