Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 7,361	$ 4,816	$ 17,019	$ 6,527
Other comprehensive income (loss), net of tax:
Gain (loss) on derivative instrument classified as cash flow hedge, including a tax effect of ($339) and $2,074 for the three and nine months ended June 30, 2017, respectively, and ($595) and ($1,699) for the three and nine months ended June 30, 2016	(499)	(877)	3,055	(2,503)
Comprehensive income	$ 6,862	$ 3,939	$ 20,074	$ 4,024