Amounts Related to Transportation and Terminaling Business (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenue from external customers	$ 1,309,000	$ 1,714,000	$ 2,610,000	$ 3,486,000
Interest expense	46,000	61,000	87,000	116,000
Depreciation and amortization	147,000	165,000	297,000	330,000
Income tax (expense) benefit		(121,000)		(93,000)
Net income (loss)	(275,000)	(589,000)	(722,000)	(836,000)
Total assets	8,661,000		8,661,000		9,311,000
Transportation and Terminaling Business
Segment Reporting Information [Line Items]
Revenue from external customers	1,309,000	1,714,000
Interest expense	139,000	125,000
Depreciation and amortization	147,000	165,000
Income tax (expense) benefit		121,000
Net income (loss)	(187,000)	147,000
Total assets	$ 8,610,000		$ 8,610,000		$ 9,498,000