Summary of Significant Accounting Policies (Schedule Of Computation Of Basic And Diluted Net Income Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accounting Policies [Abstract]
Net income	$ 68,178	$ 72,336	$ 201,083	$ 207,469
Weighted average shares outstanding - basic	78,516	79,135	78,636	79,188
Dilutive effect of common shares from stock options and restricted stock units	348	520	571	646
Weighted average shares outstanding - diluted	78,864	79,655	79,207	79,834
Basic net income per share (dollars per share)	$ 0.87	$ 0.91	$ 2.56	$ 2.62
Diluted net income per share (dollars per share)	$ 0.86	$ 0.91	$ 2.54	$ 2.60