Note 13 - Segment Information (Detail) - Schedule Of Segment Reporting Information (USD $)	3 Months Ended		9 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2012	Aug. 31, 2011
Revenue from external customers	$ 11,534,000	$ 9,252,000	$ 29,531,000	$ 21,761,000
Income (loss) from operations	1,607,000	1,438,000	3,463,000	1,327,000
Income (loss) before tax	1,495,000	1,364,000	3,189,000	1,083,000
Total Assets	32,894,000	27,028,000	32,894,000	27,028,000
Capital expenditures	294,000	296,000	1,961,000	959,000
Depreciation & Amortization	218,000	203,000	634,000	605,000
Agricultural Products [Member]
Revenue from external customers	8,176,000	7,771,000	20,170,000	18,091,000
Income (loss) from operations	1,027,000	1,358,000	2,202,000	1,830,000
Income (loss) before tax	988,000	1,351,000	2,149,000	1,804,000
Total Assets	24,082,000	20,527,000	24,082,000	20,527,000
Capital expenditures	289,000	207,000	1,929,000	473,000
Depreciation & Amortization	137,000	123,000	390,000	375,000
Pressurized Vessels [Member]
Revenue from external customers	566,000	403,000	1,512,000	1,368,000
Income (loss) from operations	10,000	(11,000)	(108,000)	(332,000)
Income (loss) before tax	(47,000)	(65,000)	(278,000)	(500,000)
Total Assets	2,722,000	2,843,000	2,722,000	2,843,000
Capital expenditures	0	2,000	5,000	89,000
Depreciation & Amortization	29,000	26,000	86,000	78,000
Modular Buildings [Member]
Revenue from external customers	2,792,000	1,078,000	7,849,000	2,302,000
Income (loss) from operations	570,000	91,000	1,369,000	(171,000)
Income (loss) before tax	554,000	78,000	1,318,000	(221,000)
Total Assets	6,090,000	3,658,000	6,090,000	3,658,000
Capital expenditures	5,000	87,000	27,000	397,000
Depreciation & Amortization	$ 52,000	$ 54,000	$ 158,000	$ 152,000