Investment Securities (Schedule Of Maturities Of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Investment Holdings [Line Items]
Available-for-sale Securities, Three months or less, Amortized Cost	$ 41,701
Available-for-sale Securities, Over three months through twelve months, Amortized Cost	363,905
Available-for-sale Securities, After one through five Years, Amortized Cost	1,749,176
Available-for-sale Securities, After five through ten years, Amortized Cost	565,350
Available-for-sale Securities, After ten years, Amortized Cost	60,410
Available-for-sale Securities, Amortized Cost	2,782,501
Available-for-sale Securities, Three months or less, Fair Value	42,031
Available-for-sale Securities, Over three months through twelve months, Fair Value	367,679
Available-for-sale Securities, After one through five years, Fair Value	1,784,023
Available-for-sale Securities, After five through ten years, Fair Value	575,258
Available-for-sale Securities, After ten years, Fair Value	62,992
Available-for-sale Securities, Fair Value	2,834,076
Held-to-maturity Securities, Over three months through twelve months, Amortized Cost	595
Held-to-maturity Securities, After one through five years, Amortized Cost	880
Held-to-maturity Securities, After five through ten years, Amortized Cost	807
Held-to-maturity Securities, After ten years, Amortized Cost	2,224
Held-to-maturity Securities, Amortized Cost	4,506
Held-to-maturity Securities, Over three months through twelve months, Fair Value	597
Held-to-maturity Securities, After one through five years, Fair Value	854
Held-to-maturity Securities, After five through ten years, Fair Value	771
Held-to-maturity Securities, After ten years, Fair Value	2,224
Held-to-maturity Securities, Fair Value	4,446
Other Investments Securities [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	1,959
Available-for-sale Securities, Fair Value	$ 2,093