Earnings Per Share - Schedule of Earnings Per Share, Basic and Dilutive (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
(Loss) income from continuing operations	$ 60,484	$ 13,429	$ 11,616	$ (130,575)	$ 33,693	$ 7,114	$ (7,495)	$ (1,359)	$ (45,046)	$ 31,953	$ 5,205
Loss from discontinued operations, net of tax									(329)	(140)	(512)
Net (loss) income									$ (45,375)	$ 31,813	$ 4,693
Basic weighted-average shares									32,141	31,952	31,798
Dilutive effect of restricted stock awards									0	433	5
Dilutive effect of stock options									0	41	0
Diluted weighted-average shares (in shares)									32,141	32,426	31,803
Basic (loss) income per share:
Continuing operations (in dollars per share)	$ 1.88	$ 0.42	$ 0.36	$ (4.07)	$ 1.05	$ 0.22	$ (0.23)	$ (0.04)	$ (1.40)	$ 1.00	$ 0.16
Discontinued operations (in dollars per share)									(0.01)	0.00	(0.01)
Total (in dollars per share)									(1.41)	1.00	0.15
Diluted (loss) income per share:
Continuing operations (in dollars per share)	$ 1.83	$ 0.41	$ 0.36	$ (4.07)	$ 1.03	$ 0.22	$ (0.23)	$ (0.04)	(1.40)	0.99	0.16
Discontinued operations (in dollars per share)									(0.01)	0.00	(0.01)
Total (in dollars per share)									$ (1.41)	$ 0.99	$ 0.15