CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Net income		$ 44,934	$ 37,556	$ 36,084
Other comprehensive income (loss):
Unrealized gain (loss) on pension plan obligation	[1]	3,067	1,827	(1,070)
Tax effect of unrealized gain (loss) on pension plan obligation		(1,285)	(753)	463
Total other comprehensive income (loss)		1,782	1,074	(607)
Total comprehensive income		$ 46,716	$ 38,630	$ 35,477

[1] These items are included in the computation of net periodic pension cost. See Note 12 - Employee Benefit Plans.