Note 12 - Segment Information (Details) - Segment reporting information (USD $)	3 Months Ended		6 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012	Nov. 30, 2012
Segment Reporting Information [Line Items]
Revenue from external customers	$ 9,250,308	$ 11,685,169	$ 17,665,413	$ 17,997,383
Income (loss) from operations	798,959	1,493,766	1,511,713	1,856,021
Income (loss) before tax	709,777	1,404,478	1,971,210	1,693,556
Total Assets	31,445,515	35,115,000	31,445,515	35,115,000	31,228,676
Capital expenditures	66,000	1,561,000	210,000	1,667,000
Depreciation & Amortization	171,000	203,000	370,000	408,000
Agricultural Products [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	7,716,000	8,006,000	14,720,000	11,994,000
Income (loss) from operations	568,000	1,038,000	1,129,000	1,174,000
Income (loss) before tax	517,000	1,024,000	1,693,000	1,161,000
Total Assets	25,531,000	25,014,000	25,531,000	25,014,000
Capital expenditures	58,000	1,563,000	197,000	1,640,000
Depreciation & Amortization	96,000	121,000	247,000	245,000
Pressurized Vessels [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	642,000	617,000	1,036,000	946,000
Income (loss) from operations	(12,000)	(30,000)	(135,000)	(118,000)
Income (loss) before tax	(38,000)	(87,000)	(214,000)	(231,000)
Total Assets	2,891,000	2,791,000	2,891,000	2,791,000
Capital expenditures	5,000	(9,000)	9,000	5,000
Depreciation & Amortization	26,000	29,000	52,000	57,000
Modular Buildings [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	892,000	3,062,000	1,909,000	5,057,000
Income (loss) from operations	243,000	485,000	518,000	800,000
Income (loss) before tax	231,000	468,000	492,000	763,000
Total Assets	3,024,000	7,310,000	3,024,000	7,310,000
Capital expenditures	3,000	7,000	4,000	22,000
Depreciation & Amortization	$ 49,000	$ 53,000	$ 71,000	$ 106,000