Loans Receivable And Allowance For Credit Losses (Recorded Investment Of Loans, Past Due) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	$ 27,963	$ 27,614
Financing receivable, 90 or More Days Delinquent or in Foreclosure	21,244	19,564
Financing receivable, Total Delinquent Loans	49,207	47,178
Financing receivable, Current Loans	5,984,301	5,920,512
Financing receivable, Total Recorded Investment	6,033,508	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	19,183	18,889
Financing receivable, 90 or More Days Delinquent or in Foreclosure	10,541	9,379
Financing receivable, Total Delinquent Loans	29,724	28,268
Financing receivable, Current Loans	5,191,936	5,092,581
Financing receivable, Total Recorded Investment	5,221,660	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	7,959	7,842
Financing receivable, 90 or More Days Delinquent or in Foreclosure	10,215	9,695
Financing receivable, Total Delinquent Loans	18,174	17,537
Financing receivable, Current Loans	605,955	631,050
Financing receivable, Total Recorded Investment	624,129	648,587
Multi-Family And Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, Current Loans	47,229	57,603
Financing receivable, Total Recorded Investment	47,229	57,603
Consumer - Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	721	848
Financing receivable, 90 or More Days Delinquent or in Foreclosure	477	485
Financing receivable, Total Delinquent Loans	1,198	1,333
Financing receivable, Current Loans	133,825	133,695
Financing receivable, Total Recorded Investment	135,023	135,028
Consumer - Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 Days Delinquent	100	35
Financing receivable, 90 or More Days Delinquent or in Foreclosure	11	5
Financing receivable, Total Delinquent Loans	111	40
Financing receivable, Current Loans	5,356	5,583
Financing receivable, Total Recorded Investment	$ 5,467	$ 5,623