Segment Information - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue recognition
Increase (decrease) in operating income	$ 13,893	$ 10,293	$ (3,270)	$ 40,678
Increase (decrease) in net income	$ 4,498	$ 8,786	$ 9,228	$ 2,937
Increase (decrease) in net income per common share (in dollars per share)	$ 0.17	$ 0.33	$ 0.34	$ 0.11
Unallocated corporate expenses and other
Revenue recognition
Increase (decrease) in operating income	$ (12,300)	$ (7,700)	$ (32,800)	$ (17,100)
Expense related to the development of ERP system	5,100	4,700	17,100	6,600
Change in estimated total costs | Adjustment
Revenue recognition
Increase (decrease) in operating income	200	0	(3,100)	(13,800)
Increase (decrease) in net income	$ 100	$ 300	$ (1,800)	$ (10,700)
Increase (decrease) in net income per common share (in dollars per share)		$ 0.01	$ (0.07)	$ (0.40)