Loans Receivable And Allowance For Credit Losses (Recorded Investment Of Loans, Past Due) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	$ 22,189	$ 27,614
Financing receivable, 90 or More Days Delinquent or in Foreclosure	20,623	19,564
Financing receivable, Total Delinquent Loans	42,812	47,178
Financing receivable, Current Loans	6,020,052	5,920,512
Financing receivable, Total Recorded Investment	6,062,864	5,967,690
One-To Four-Family Loans - Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	14,111	18,889
Financing receivable, 90 or More Days Delinquent or in Foreclosure	9,921	9,379
Financing receivable, Total Delinquent Loans	24,032	28,268
Financing receivable, Current Loans	5,238,614	5,092,581
Financing receivable, Total Recorded Investment	5,262,646	5,120,849
One-To Four-Family Loans - Purchased [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	7,361	7,842
Financing receivable, 90 or More Days Delinquent or in Foreclosure	10,389	9,695
Financing receivable, Total Delinquent Loans	17,750	17,537
Financing receivable, Current Loans	590,920	631,050
Financing receivable, Total Recorded Investment	608,670	648,587
Multi-Family And Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, Current Loans	56,236	57,603
Financing receivable, Total Recorded Investment	56,236	57,603
Consumer - Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	665	848
Financing receivable, 90 or More Days Delinquent or in Foreclosure	305	485
Financing receivable, Total Delinquent Loans	970	1,333
Financing receivable, Current Loans	129,351	133,695
Financing receivable, Total Recorded Investment	130,321	135,028
Consumer - Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	52	35
Financing receivable, 90 or More Days Delinquent or in Foreclosure	8	5
Financing receivable, Total Delinquent Loans	60	40
Financing receivable, Current Loans	4,931	5,583
Financing receivable, Total Recorded Investment	$ 4,991	$ 5,623