Securities (Schedule Of Contractual Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Securities [Abstract]
Available-for-sale Securities, One year or less, Amortized Cost	$ 201
Available-for-sale Securities, One year through five years, Amortized Cost	610,941
Available-for-sale Securities, Five years through ten years, Amortized Cost	149,405
Available-for-sale Securities, Ten years and thereafter, Amortized Cost	225,704
Available-for-sale Securities, Amortized Cost	986,251	1,058,283
Available-for-sale Securities, One year or less, Estimated Fair Value	205
Available-for-sale Securities, One year through five years, Estimated Fair Value	603,278
Available-for-sale Securities, Five years through ten years, Estimated Fair Value	153,498
Available-for-sale Securities, Ten years and thereafter, Estimated Fair Value	236,612
Available-for-sale Securities, Estimated Fair Value	993,593	1,069,967
Held-to-maturity Securities, One year or less, Amortized Cost	6,732
Held-to-maturity Securities, One year through five years, Amortized Cost	60,583
Held-to-maturity Securities, Five years through ten years, Amortized Cost	403,933
Held-to-maturity Securities, Ten years and thereafter, Amortized Cost	1,197,236
Held-to-maturity Securities, Amortized Cost	1,668,484	1,718,023
Held-to-maturity Securities, One year or less, Estimated Fair Value	6,803
Held-to-maturity Securities, One year through five years, Estimated Fair Value	63,560
Held-to-maturity Securities, Five years through ten years, Estimated Fair Value	400,427
Held-to-maturity Securities, Ten years and thereafter, Estimated Fair Value	1,199,307
Held-to-maturity Securities, Estimated Fair Value	$ 1,670,097	$ 1,741,846