Related Party Transactions (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Aquila [Member]
Related Party Transaction [Line Items]
Sales to related party	$ 3,388	$ 5,844	$ 6,271
Aquila [Member] | Understated Sales [Member]
Related Party Transaction [Line Items]
Sales to related party		215
Nagase-Landauer, Ltd [Member]
Related Party Transaction [Line Items]
Sales to related party	$ 4,613	1,924	$ 1,341
Nagase-Landauer, Ltd [Member] | Understated Sales [Member]
Related Party Transaction [Line Items]
Sales to related party		$ 271
Nagase-Landauer, Ltd [Member]
Related Party Transaction [Line Items]
Equity percentage in joint venture	50.00%
Epsilon Landauer Dozimetri [Member]
Related Party Transaction [Line Items]
Equity percentage in joint venture	50.00%
Yamasato, Fujiwara, Higa and Associates, Inc [Member]
Related Party Transaction [Line Items]
Equity percentage in joint venture	49.00%