CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Marketing	$ 1,267,275	$ 1,043,775	$ 1,875,885
Transportation	53,358	52,355	63,331
Oil and natural gas	1,427	3,410	5,063
Total revenues	1,322,060	1,099,540	1,944,279
Costs and expenses:
Marketing	1,247,763	1,016,733	1,841,893
Transportation	48,538	45,154	52,076
Oil and natural gas	948	2,084	6,931
Oil and natural gas property impairments	3	313	12,082
General and administrative	9,707	10,410	9,939
Depreciation, depletion and amortization	13,599	18,792	23,717
Total costs and expenses	1,320,558	1,093,486	1,946,638
Operating earnings (losses)	1,502	6,054	(2,359)
Other income (expense):
Loss on deconsolidation of subsidiary (Note 3)	(3,505)	0	0
Impairment of investment in unconsolidated affiliate	(2,500)	0	0
Interest income	1,103	582	327
Interest expense	(27)	(2)	(13)
Total other income (expense), net	(4,929)	580	314
(Losses) earnings before income taxes and investment in unconsolidated affiliate	(3,427)	6,634	(2,045)
Income tax (provision) benefit:
Current	(895)	(2,778)	(4,073)
Deferred	3,840	87	4,843
Income tax benefit (provision)	2,945	(2,691)	770
Earnings (losses) from continuing operations	(482)	3,943	(1,275)
Losses from investments in unconsolidated affiliates, net of tax benefit of $—, $770 and $—, respectively	0	(1,430)	0
Net (losses) earnings	$ (482)	$ 2,513	$ (1,275)
Earnings (losses) per share:
From continuing operations (in dollars per share)	$ (0.11)	$ 0.94	$ (0.30)
From investment in unconsolidated affiliate (in dollars per share)	0.00	(0.34)	0.00
Basic and diluted net (losses) earnings per common share (in dollars per share)	$ (0.11)	$ 0.60	$ (0.30)
Weighted average number of common shares outstanding (in shares)	4,218	4,218	4,218
Dividends per common share (in dollars per share)	$ 0.88	$ 0.88	$ 0.88