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	Dec. 31, 2013	Dec. 31, 2012
Debt securities, Available-for-sale, Amortized cost, Within one year	$ 160,392
Debt securities, Available-for-sale, Amortized cost, After one year through three years	169,499
Debt securities, Available-for-sale, Amortized cost, After three years through five years	123,643
Debt securities, Available-for-sale, Amortized cost, After five years through ten years	407,866
Debt securities, Available-for-sale, Amortized cost, After ten years	502,087
Debt securities, Available-for-sale, Amortized cost, Total	1,762,516
Debt securities, Available-for-sale, Estimated fair value, Within one year	161,647
Debt securities, Available-for-sale, Estimated fair value, After one year through three years	172,158
Debt securities, Available-for-sale, Estimated fair value, After three years through five years	123,862
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years	406,477
Debt securities, Available-for-sale, Estimated fair value, After ten years	492,257
Debt securities, Available-for-sale, Estimated fair value, Total	1,756,253
Debt securities, Held-to-maturity, Amortized cost, Within one year
Debt securities, Held-to-maturity, Amortized cost, After one year through three years	15,050
Debt securities, Held-to-maturity, Amortized cost, After three years through five years	40,279
Debt securities, Held-to-maturity, Amortized cost, After five years through ten years
Debt securities, Held-to-maturity, Amortized cost, After ten years	228,623
Held-to-maturity Securities, Amortized cost	1,312,115	708,008
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	14,779
Debt securities, Held-to-maturity, Estimated fair value, After three years through five years	37,955
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	232,007
Held-to-maturity securities, Estimated fair value	1,305,959	715,274
Mortgage-backed securities [Member]
Debt securities, Available-for-sale, Amortized cost, After one year through three years	9,090
Debt securities, Available-for-sale, Amortized cost, After three years through five years	2,681
Debt securities, Available-for-sale, Amortized cost, After five years through ten years	69,924
Debt securities, Available-for-sale, Amortized cost, After ten years	317,334
Debt securities, Available-for-sale, Estimated fair value, After one year through three years	9,236
Debt securities, Available-for-sale, Estimated fair value, After three years through five years	2,702
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years	69,559
Debt securities, Available-for-sale, Estimated fair value, After ten years	318,355
Debt securities, Held-to-maturity, Amortized cost, After one year through three years	10
Debt securities, Held-to-maturity, Amortized cost, After three years through five years
Debt securities, Held-to-maturity, Amortized cost, After five years through ten years	59,404
Debt securities, Held-to-maturity, Amortized cost, After ten years	968,749
Debt securities, Held-to-maturity, Estimated fair value, After one year through three years	10
Debt securities, Held-to-maturity, Estimated fair value, After three years through five years
Debt securities, Held-to-maturity, Estimated fair value, After five years through ten years	59,219
Debt securities, Held-to-maturity, Estimated fair value, After ten years	$ 961,989