Segment Information (Tables)

3 Months Ended

Mar. 31, 2016

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

The following table summarizes certain financial information for each of the Partnership's operating segments (in thousands):

	Operating Segments
For the Three Months Ended	Coal, Hard Mineral Royalty and Other		Soda Ash		VantaCore			Oil and Gas			Corporate and Financing			Total
For the three months ended March 31, 2016
Revenues (including affiliates)	$	39,045	$	9,801	$	24,682		$	7,298		$	—		$	80,826
Intersegment revenues (expenses)	21		—		(21		)	—			—			—
Gain on asset sales	1,590		—		—			20,335			—			21,925
Operating and maintenance expenses (including affiliates)	7,380		—		22,156			5,114			—			34,650
Depreciation, depletion and amortization	6,762		—		3,562			4,419			—			14,743
Asset impairment	1,893		—		—			137			—			2,030
Interest expense, net	—		—		—			—			(23,729		)	(23,729		)
Net income (loss)	24,600		9,801		(1,036		)	17,963			(27,901		)	23,427
For the three months ended March 31, 2015
Revenues (including affiliates)	$	53,510	$	12,523	$	26,799		$	14,779		$	—		$	107,611
Gain on asset sales	1,615		—		—			451			—			2,066
Operating and maintenance expenses (including affiliates)	8,414		—		25,434			6,649			—			40,497
Depreciation, depletion and amortization	10,016		—		3,856			11,520			—			25,392
Interest expense, net	—		—		—			—			(22,928		)	(22,928		)
Net income (loss)	36,695		12,523		(2,491		)	(2,939		)	(26,299		)	17,489
Total assets
March 31, 2016	1,016,827		258,939		196,720			132,324			20,083			1,624,893
December 31, 2015	1,047,922		261,942		200,348			158,862			961			1,670,035