Quarterly Results Of Operations (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 162,847		$ 150,800		$ 162,295		$ 171,872		$ 176,235		$ 171,733		$ 146,041		$ 146,858		$ 647,814		$ 640,867		$ 690,741
Gross profit	25,746		29,642		34,928		35,158		39,954		36,593		29,543		32,402		125,474		138,492		132,803
Income from continuing operations	2,429		2,947		6,976		7,268		17,334		9,083		6,202		7,120		19,620		39,739		28,743
Net income	$ 2,429		$ 2,947		$ 15,593		$ 8,255		$ 18,568		$ 9,305		$ 6,818		$ 7,385		$ 29,224		$ 42,076		$ 29,657
Earnings per share ─ continuing operations:
Continuing operations	$ 0.20		$ 0.25		$ 0.58		$ 0.61		$ 1.45		$ 0.76		$ 0.52		$ 0.60		$ 1.63		$ 3.32		$ 2.43
Continuing operations	$ 0.20		$ 0.24		$ 0.58		$ 0.60		$ 1.44		$ 0.76		$ 0.52		$ 0.60		$ 1.62		$ 3.32		$ 2.41
Earnings per share:
Basic	$ 0.20	[1]	$ 0.25	[1]	$ 1.30	[1]	$ 0.69	[1]	$ 1.55	[2]	$ 0.78	[2]	$ 0.57	[2]	$ 0.62	[2]	$ 2.43	[1]	$ 3.52	[2]	$ 2.50
Diluted	$ 0.20	[1]	$ 0.24	[1]	$ 1.29	[1]	$ 0.68	[1]	$ 1.54	[2]	$ 0.78	[2]	$ 0.57	[2]	$ 0.62	[2]	$ 2.42	[1]	$ 3.51	[2]	$ 2.49

[1] The increase in earnings per share for the second quarter of Fiscal 2014 was primarily due to the sale of Transdyn. For additional information on this disposition, see Note N.

[2] The increase in earnings per share for the fourth quarter of Fiscal 2013 was primarily driven by the release of our Canadian valuation allowance. For an explanation of the effective tax rate in Fiscal 2013, see Note H.