Available-For-Sale And Held-To-Maturity Securities (Schedule Of Amortized Cost And Fair Values Of Debt Securities By Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Debt securities, Available-for-sale, Amortized cost, Within one year	$ 81,583
Debt securities, Available-for-sale, Amortized cost, After one year through three years	294,073
Debt securities, Available-for-sale, Amortized cost, After three years through five years	104,097
Debt securities, Available-for-sale, Amortized cost, After five years through ten years	5,600
Debt securities, Available-for-sale, Amortized cost, After ten years	127,101
Debt securities, Available-for-sale, Amortized cost, Total	1,312,350
Debt securities, Available-for-sale, Estimated fair value, Within one year	81,942
Debt securities, Available-for-sale, Estimated fair value, After one year through three years	296,928
Debt securities, Available-for-sale, Estimated fair value, After three years through five years	101,828
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years	6,227
Debt securities, Available-for-sale, Estimated fair value, After ten years	131,924
Debt securities, Available-for-sale, Estimated fair value, Total	1,329,359
Debt securities, Held-to-maturity, Amortized cost, Within one year
Debt securities, Held-to-maturity, Amortized cost, After one year through three years
Debt securities, Held-to-maturity, Amortized cost, After three years through five years	34,988
Debt securities, Held-to-maturity, Amortized cost, After five years through ten years	201,419
Debt securities, Held-to-maturity, Amortized cost, After ten years	284,971
Debt securities, Held-to-maturity, Amortized cost, Total	521,378
Debt securities, Held-to-maturity, Estimated fair value, Within one year
Debt securities, Held-to-maturity, Estimated fair value, After one year through three years
Debt securities, Held-to-maturity, Estimated fair value, After three years through five years	34,222
Debt securities, Held-to-maturity, Estimated fair value, After five years through ten years	200,480
Debt securities, Held-to-maturity, Estimated fair value, After ten years	290,506
Debt securities, Held-to-maturity, Estimated fair value, Total	525,208
Mortgage-backed securities [Member]
Debt securities, Available-for-sale, Amortized cost, After one year through three years	9,469
Debt securities, Available-for-sale, Amortized cost, After five years through ten years	16,280
Debt securities, Available-for-sale, Amortized cost, After ten years	673,740
Debt securities, Available-for-sale, Estimated fair value, After one year through three years	9,922
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years	16,640
Debt securities, Available-for-sale, Estimated fair value, After ten years	683,529
Debt securities, Held-to-maturity, Amortized cost, After one year through three years
Debt securities, Held-to-maturity, Amortized cost, After five years through ten years
Debt securities, Held-to-maturity, Amortized cost, After ten years
Debt securities, Held-to-maturity, Estimated fair value, After one year through three years
Debt securities, Held-to-maturity, Estimated fair value, After five years through ten years
Debt securities, Held-to-maturity, Estimated fair value, After ten years