EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Numerator:
Income from continuing operations	$ (21,208)	$ 90,887	$ 149,536	$ 203,057	$ 168,705	$ 192,290	$ 174,589	$ 173,182	$ 422,272	$ 708,766	$ 721,453
Income (loss) from discontinued operations									(47)	(47)	15,186
NET INCOME (LOSS)	$ (21,214)	$ 90,860	$ 149,537	$ 203,042	$ 168,688	$ 192,279	$ 174,570	$ 173,182	422,225	708,719	736,639
Adjustment for basic earnings per share:
Earnings allocated to unvested shareholders									(2,174)	(4,145)	(3,842)
Numerator for basic earnings per share:
From continuing operations									420,098	704,621	717,611
From discontinued operations									(47)	(47)	15,186
Net income (loss) attributable to parent, basic									420,051	704,574	732,797
Adjustment for diluted earnings per share:
Effect of reallocating undistributed earnings of unvested shareholders									6	30	46
Numerator for diluted earnings per share:
From continuing operations									420,104	704,651	717,657
From discontinued operations									(47)	(47)	15,186
Net income (loss) attributable to parent, diluted									$ 420,057	$ 704,604	$ 732,843
Denominator:
Denominator for basic earnings per share - weighted-average shares									107,754	107,800	106,286
Effect of dilutive shares from stock options and restricted stock (in shares)									816	1,341	1,593
Denominator for diluted earnings per share - adjusted weighted-average shares									108,570	109,141	107,879
Basic earnings per common share:
Income from continuing operations (in dollars per share)	$ (0.20)	$ 0.84	$ 1.38	$ 1.87	$ 1.55	$ 1.77	$ 1.61	$ 1.61	$ 3.90	$ 6.54	$ 6.75
Income from discontinued operations (in dollars per share)											0.14
Net income (in dollars per share)	(0.20)	0.84	1.38	1.87	1.55	1.77	1.61	1.61	3.90	6.54	6.89
Diluted earnings per common share:
Income from continuing operations (in dollars per share)	(0.20)	0.83	1.37	1.85	1.53	1.75	1.59	1.59	3.87	6.46	6.65
Income from discontinued operations (in dollars per share)											0.14
Net income (in dollars per share)	$ (0.20)	$ 0.83	$ 1.37	$ 1.85	$ 1.53	$ 1.75	$ 1.59	$ 1.59	$ 3.87	$ 6.46	$ 6.79
Outstanding equity awards
Shares excluded from calculation of diluted earnings per share									667	215	743
Weighted-average price per share (in dollars per share)									$ 72.85	$ 79.67	$ 57.27