Loans Receivable And Allowance For Credit Losses (Recorded Investment in Loans, Past Due) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 days delinquent	$ 24,172	$ 27,614
Financing receivable, 90 or more days delinquent or in foreclosure	16,166	19,564
Financing receivable, total delinquent loans	40,338	47,178
Financing receivable, current loans	6,202,059	5,920,512
Financing receivable, total recorded investment	6,242,397	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	15,396	18,889
Financing receivable, 90 or more days delinquent or in foreclosure	8,566	9,379
Financing receivable, total delinquent loans	23,962	28,268
Financing receivable, current loans	5,421,112	5,092,581
Financing receivable, total recorded investment	5,445,074	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	7,937	7,842
Financing receivable, 90 or more days delinquent or in foreclosure	7,190	9,695
Financing receivable, total delinquent loans	15,127	17,537
Financing receivable, current loans	550,229	631,050
Financing receivable, total recorded investment	565,356	648,587
Multi-Family And Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 days delinquent	0	0
Financing receivable, 90 or more days delinquent or in foreclosure	0	0
Financing receivable, total delinquent loans	0	0
Financing receivable, current loans	96,946	57,603
Financing receivable, total recorded investment	96,946	57,603
Consumer - Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 days delinquent	770	848
Financing receivable, 90 or more days delinquent or in foreclosure	397	485
Financing receivable, total delinquent loans	1,167	1,333
Financing receivable, current loans	129,317	133,695
Financing receivable, total recorded investment	130,484	135,028
Consumer - Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, 30 to 89 days delinquent	69	35
Financing receivable, 90 or more days delinquent or in foreclosure	13	5
Financing receivable, total delinquent loans	82	40
Financing receivable, current loans	4,455	5,583
Financing receivable, total recorded investment	$ 4,537	$ 5,623