Securities (Schedule Of Estimated Fair Value And Gross Unrealized Losses Of Securities In Continuous Unrealized Loss Position) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014 security	Sep. 30, 2013 security
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Count	21	19
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value	$ 468,011	$ 426,482
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	7,537	7,213
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Count	3	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value	40,310	26,750
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses	1,380	844
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value	789,855	711,590
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	17,275	16,998
Held-to-maturity Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value	22,566
Held-to-maturity Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses	1,292
Less Than 12 Months [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Count	52	43
Equal to or Greater Than 12 Months [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Count	2
GSE Debentures [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Count	20	19
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value	457,820	426,482
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	7,467	7,213
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Count	2	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value	37,941	24,327
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses	1,210	673
Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Count	1	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value	2,369	2,423
Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses	170	171
MBS [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Count	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value	10,191
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	70
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value	784,469	710,291
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	17,239	16,984
Held-to-maturity Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value	22,566
Held-to-maturity Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses	1,292
MBS [Member] | Less Than 12 Months [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Count	44	40
MBS [Member] | Equal to or Greater Than 12 Months [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Count	2
Municipal Bonds [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value	5,386	1,299
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	$ 36	$ 14
Municipal Bonds [Member] | Less Than 12 Months [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Count	8	3