Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income (loss)	$ 18,789	$ (11,258)
Total basic average common shares outstanding	161,922,633	165,540,789
Total diluted average common shares outstanding	161,930,727	165,540,789
Basic	$ 0.12	$ (0.07)
Diluted	$ 0.12	$ (0.07)
Antidilutive stock options and RRP, excluded from the diluted average common shares outstanding calculation	897,136
Antidilutive RRP shares excluded from computation of diluted earnings per share		4,753
Antidilutive stock options excluded from computation of diluted earnings per share		4,743
Average Common Shares Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total basic average common shares outstanding	161,921,133	165,539,517
Average Committed ESOP Shares Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total basic average common shares outstanding	1,500	1,272
Effect Of Dilutive RRP Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total diluted average common shares outstanding	4,351
Effect Of Dilutive Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total diluted average common shares outstanding	3,743