Loans Receivable And Allowance For Credit Losses (Recorded Investment Of Loans, Past Due) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	$ 23,287	$ 27,614
Financing receivable, 90 or More Days Delinquent or in Foreclosure	17,171	19,564
Financing receivable, Total Delinquent Loans	40,458	47,178
Financing receivable, Current Loans	6,101,144	5,920,512
Financing receivable, Total Recorded Investment	6,141,602	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	15,704	18,889
Financing receivable, 90 or More Days Delinquent or in Foreclosure	8,414	9,379
Financing receivable, Total Delinquent Loans	24,118	28,268
Financing receivable, Current Loans	5,319,093	5,092,581
Financing receivable, Total Recorded Investment	5,343,211	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	6,915	7,842
Financing receivable, 90 or More Days Delinquent or in Foreclosure	8,388	9,695
Financing receivable, Total Delinquent Loans	15,303	17,537
Financing receivable, Current Loans	569,584	631,050
Financing receivable, Total Recorded Investment	584,887	648,587
Multi-Family And Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, Current Loans	77,899	57,603
Financing receivable, Total Recorded Investment	77,899	57,603
Consumer - Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	628	848
Financing receivable, 90 or More Days Delinquent or in Foreclosure	345	485
Financing receivable, Total Delinquent Loans	973	1,333
Financing receivable, Current Loans	129,672	133,695
Financing receivable, Total Recorded Investment	130,645	135,028
Consumer - Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	40	35
Financing receivable, 90 or More Days Delinquent or in Foreclosure	24	5
Financing receivable, Total Delinquent Loans	64	40
Financing receivable, Current Loans	4,896	5,583
Financing receivable, Total Recorded Investment	$ 4,960	$ 5,623