Discontinued Operations (Details) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Apr. 01, 2012	Mar. 31, 2013	Apr. 01, 2012
Thermal Imaging [Member]
Summarized financial information related to the Thermal Imaging Business and is segregated from continuing operations and reported as discontinued operations
Total revenues				$ 1,983,000
Cost and expenses
Cost of revenues				1,810,000
General and administrative expense		45,000		87,000
Research and development expense		220,000		574,000
Total costs and expenses		265,000		2,471,000
Loss from operations		(265,000)		(488,000)
Gain on disposal, net of income taxes		7,748,000		7,748,000
Net earnings from discontinued operations		7,483,000		7,260,000
Government Business [Member]
Summarized financial information related to the Thermal Imaging Business and is segregated from continuing operations and reported as discontinued operations
Total revenues	732,000	1,203,000	1,514,000	2,499,000
Cost and expenses
Cost of revenues	1,278,000	1,013,000	2,606,000	1,974,000
General and administrative expense	323,000	514,000	882,000	1,952,000
Research and development expense	322,000	259,000	764,000	644,000
Total costs and expenses	1,923,000	1,786,000	4,252,000	4,570,000
Net earnings from discontinued operations	$ (1,191,000)	$ (583,000)	$ (2,738,000)	$ (2,071,000)