Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 segment	Mar. 31, 2013
Reporting segments			3
Revenues	$ 39,554	$ 37,082	$ 77,259	$ 73,763
Operating income (loss)	7,365	7,154	12,390	13,881
Radiation Measurement [Member]
Revenues	29,184	27,249	56,925	53,652
Operating income (loss)	10,301	10,141	18,880	19,573
Medical Physics [Member]
Revenues	8,029	7,598	15,768	15,187
Operating income (loss)	600	732	1,033	1,524
Medical Products [Member]
Revenues	2,341	2,235	4,566	4,924
Operating income (loss)	(174)	304	(612)	974
Corporate [Member]
Operating income (loss)	$ (3,362)	$ (4,023)	$ (6,911)	$ (8,190)