Earnings Per Common Share (Computation of Basic and Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Common Share [Abstract]
Net income, Basic earnings per share	$ 72,831	$ 65,468
Shares, Basic earnings per share	65,528	65,024
Per Share Amount, Basic earnings per share	$ 1.11	$ 1.01
Effect of dilutive securities:
Shares, stock options	409	348
Per Share Amount, Stock options	$ (0.01)	$ (0.01)
Shares, restricted stock	155	169
Per Share Amount, Restricted Stock	$ 0.00	$ 0.00
Net Income, Diluted earnings per share	$ 72,831	$ 65,468
Diluted earnings per share, Shares	66,092	65,541
Per Share Amount, Diluted earnings per share	$ 1.10	$ 1.00
Outstanding stock options, excluded in the calculation of earnings per share	296	977