CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Net income		$ 26,900	$ 44,934	$ 37,556
Other comprehensive income:
Unrealized gain on pension plan obligation	[1]	3,356	3,067	1,827
Tax effect of unrealized gain on pension plan obligation		(1,359)	(1,285)	(753)
Total other comprehensive income		1,997	1,782	1,074
Total comprehensive income		$ 28,897	$ 46,716	$ 38,630

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