Summary Of Significant Accounting Policies (Earnings Per Share Basic And Diluted) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Accounting Policies [Abstract]
Net income (loss)	$ 143,769	$ (35,398)	$ 85,424
Weighted average shares outstanding (in shares)	119,473	118,705	117,579
Dilutive effect of employee stock options, restricted shares and restricted stock units (in shares)	1,767	2,300	3,395
Diluted weighted average shares outstanding (in shares)	121,240	118,705	120,974
Basic earnings (loss) per share (in USD per share)	$ 1.20	$ (0.30)	$ 0.73
Diluted earnings (loss) per share (in USD per share)	$ 1.19	$ (0.30)	$ 0.71