Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share
Net income	$ 17,563	$ 18,789
Income allocated to participating securities (unvested restricted stock)	(60)
Net income available to common stockholders	$ 17,503	$ 18,789
Total basic average common shares outstanding	147,882,707	161,922,633
Total diluted average common shares outstanding	147,882,809	161,930,727
Basic	$ 0.12	$ 0.12
Diluted	$ 0.12	$ 0.12
Antidilutive stock options and restricted stock, excluded from the diluted average common shares outstanding calculation	2,471,473	897,136
Average Common Shares Outstanding [Member]
Earnings Per Share
Total basic average common shares outstanding	147,881,207	161,921,133
Average Committed ESOP Shares Outstanding [Member]
Earnings Per Share
Total basic average common shares outstanding	1,500	1,500
Effect of Dilutive Restricted Stock [Member]
Earnings Per Share
Total diluted average common shares outstanding		4,351
Effect Of Dilutive Stock Options [Member]
Earnings Per Share
Total diluted average common shares outstanding	102	3,743