Investment Securities (Amortized Cost And Fair Value Of Investment Securities By Contractual Maturities) (Details) (USD $) In Thousands	Sep. 30, 2011
Investment Securities [Abstract]
Amortized Cost of Securities Available-for-Sale, Due in one year or less	$ 10,081
Fair Value of Securities Available-for-Sale, Due in one year or less	10,104
Amortized Cost of Securities Held-to-Maturity, Due in one year or less	99,955
Fair Value of Securities Held-to-Maturity, Due in one year or less	101,773
Amortized Cost of Securities Available-for-Sale, Due after one year through five years	183,381
Fair Value of Securities Available-for-Sale, Due after one year through five years	181,749
Amortized Cost of Securities Available-for-Sale, Due after five years through ten years	687,624
Fair Value of Securities Available-for-Sale, Due after five years through ten years	671,599
Amortized Cost of Securities Held-to-Maturity, Due after five years through ten years	24,827
Fair Value of Securities Held-to-Maturity, Due after five years through ten years	24,940
Amortized Cost of Securities Available-for-Sale, Due after ten years	185,759	[1]
Fair Value of Securities Available-for-Sale, Due after ten years	193,919	[1]
Amortized Cost of Securities Held-to-Maturity, Due after ten years	1,110,954	[1]
Fair Value of Securities Held-to-Maturity, Due after ten years	1,159,213	[1]
Amortized Cost of Securities Available-for-Sale, Total	1,066,845
Fair Value of Securities Available-for-Sale, Total	1,057,371
Amortized Cost of Securities Held-to-Maturity, Total	1,235,736
Fair Value of Securities Held-to-Maturity, Total	$ 1,285,926

[1] Equity securities are reported in this category