Loans Receivable And Allowance For Credit Losses (Recorded Investment In Classified Loans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	$ 6,033,508	$ 5,967,690
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	28,242	33,293
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	44,240	42,788
One-To Four-Family Loans - Originated [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	5,221,660	5,120,849
One-To Four-Family Loans - Originated [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	24,631	29,359
One-To Four-Family Loans - Originated [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	28,634	27,761
One-To Four-Family Loans - Purchased [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	624,129	648,587
One-To Four-Family Loans - Purchased [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	1,665	1,871
One-To Four-Family Loans - Purchased [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	14,635	14,195
Multi-Family And Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	47,229	57,603
Multi-Family And Commercial Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	1,865	1,976
Consumer - Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	135,023	135,028
Consumer - Home Equity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	81	87
Consumer - Home Equity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	953	819
Consumer - Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	5,467	5,623
Consumer - Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, Total Recorded Investment	$ 18	$ 13