K. QUARTERLY DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 159	$ 194	$ 243	$ 195					$ 157	$ 232	$ 259	$ 172	$ 791	$ 764	$ 820
Operating (expense)	(261)	(254)	(256)	(256)	$ (327)	$ (295)	$ (233)	$ (396)	(363)	(527)	(440)	(470)	(4,061)	(1,533)	(5,122)
Corporate general and administrative expense	(91)	(95)	(122)	(100)	(33)	(52)	(101)	(166)	(120)	(176)	(155)	(154)	(408)	(352)	(605)
Gain on prepayment of debt					888	0	0	0					0	888	0
Gain on sale of land					50	0	0	0					0	50	0
Impairment of natural gas and oil properties	(2,626)	0	0	0					(2,717)	0	0	0	(2,626)	0	(2,717)
Recovery of bad debt									0	306	386	738	0	0	1,430
Other income (expense) net	(30)	65	11	(11)	(80)	(13)	(7)	(10)	(10)	(14)	(24)	(34)	29	813	1,348
Net income (loss) from continuing operations	(2,849)	(90)	(124)	(172)	738	(170)	(171)	(353)	(3,053)	(179)	26	252	(3,241)	44	(2,954)
Net income (loss) from discontinued operations	(2)	(11)	(11)	13	(97)	6	38	57	82	104	84	62	(5)	4	332
Income (loss) allocable to common shareholders	$ (2,851)	$ (101)	$ (135)	$ (159)	$ 641	$ (164)	$ (133)	$ (296)	$ (2,971)	$ (75)	$ 110	$ 314	$ (3,246)	$ 48	$ (2,622)
Income (loss) per common share - basic	$ (1.39)	$ (0.05)	$ (0.07)	$ (0.08)	$ 0.32	$ (0.08)	$ (0.07)	$ (0.15)	$ (1.53)	$ (0.04)	$ 0.06	$ 0.16