Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Numerator:
Income from continuing operations	$ 144,297	$ 104,365
Loss from discontinued operations	(11)	(215)
NET INCOME	144,286	104,150
Adjustment for basic earnings per share:
Earnings allocated to unvested shareholders	(474)	(309)
Numerator for basic earnings per share:
From continuing operations	143,823	104,056
From discontinued operations	(11)	(215)
Net income (loss) attributable to parent, basic	143,812	103,841
Adjustment for diluted earnings per share:
Effect of reallocating undistributed earnings of unvested shareholders	7	5
Numerator for diluted earnings per share:
From continuing operations	143,830	104,061
From discontinued operations	(11)	(215)
Net income (loss) attributable to parent, diluted	$ 143,819	$ 103,846
Denominator:
Denominator for basic earnings per share - weighted-average shares	107,186	106,031
Effect of dilutive shares from stock options and restricted stock	1,602	1,821
Denominator for diluted earnings per share - adjusted weighted-average shares	108,788	107,852
Basic earnings per common share:
Income from continuing operations (in dollars per share)	$ 1.34	$ 0.98
Net income (in dollars per share)	$ 1.34	$ 0.98
Diluted earnings per common share:
Income from continuing operations (in dollars per share)	$ 1.32	$ 0.96
Net income (in dollars per share)	$ 1.32	$ 0.96
Outstanding equity awards
Shares excluded from calculation of diluted earnings per share	761	324
Weighted-average price per share (in dollars per share)	$ 55.06	$ 47.94