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, 2013	Dec. 31, 2012
Net Income
Basic earnings per share	$ 83,397	$ 72,831
Stock options	0	0
Restricted stock	0	0
Diluted earnings per share	$ 83,397	$ 72,831
Shares
Basic earnings per share (in shares)	64,112	65,528
Stock options (in shares)	307	409
Restricted stock (in shares)	607	155
Diluted earnings per share (in shares)	65,026	66,092
Per Share Amount
Basic earnings per share (in dollars per share)	$ 1.30	$ 1.11
Stock options (in dollars per share)	$ (0.01)	$ (0.01)
Restricted stock (in dollars per share)	$ (0.01)	$ 0.00
Diluted earnings per share (in dollars per share)	$ 1.28	$ 1.10
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding stock options, excluded in the calculation of earnings per share	0	296