Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator:
Income (loss) from continuing operations	$ (21,193)	$ 90,899	$ 19,879	$ 448,064
Loss from discontinued operations	(7)	(27)	(3,872)	(41)
NET INCOME (LOSS)	(21,200)	90,872	16,007	448,023
Adjustment for basic earnings per share:
Earnings allocated to unvested shareholders	(451)	(558)	(1,410)	(2,801)
Numerator for basic earnings per share:
From continuing operations	(21,644)	90,341	18,469	445,263
From discontinued operations	(7)	(27)	(3,872)	(41)
Net income (loss) attributable to parent, basic	(21,651)	90,314	14,597	445,222
Adjustment for diluted earnings per share:
Effect of reallocating undistributed earnings of unvested shareholders		1		10
Numerator for diluted earnings per share:
From continuing operations	(21,644)	90,342	18,469	445,273
From discontinued operations	(7)	(27)	(3,872)	(41)
Net income (loss) attributable to parent, diluted	$ (21,651)	$ 90,315	$ 14,597	$ 445,232
Denominator:
Denominator for basic earnings per share - weighted-average shares	108,047	107,652	107,970	107,759
Effect of dilutive shares from stock options and restricted stock (in shares)		817	553	812
Denominator for diluted earnings per share - adjusted weighted-average shares	108,047	108,469	108,523	108,571
Basic earnings per common share:
Income (loss) from continuing operations (in dollars per share)	$ (0.20)	$ 0.84	$ 0.18	$ 4.13
Loss from discontinued operations (in dollars per share)			(0.04)
Net income (loss) (in dollars per share)	(0.20)	0.84	0.14	4.13
Diluted earnings per common share:
Income (loss) from continuing operations (in dollars per share)	(0.20)	0.83	0.17	4.10
Loss from discontinued operations (in dollars per share)			(0.04)
Net income (loss) (in dollars per share)	$ (0.20)	$ 0.83	$ 0.13	$ 4.10
Outstanding equity awards
Shares excluded from calculation of diluted earnings per share	3,409	592	1,861	667
Weighted-average price per share (in dollars per share)	$ 51.94	$ 73.36	$ 63.70	$ 72.85