Available-For-Sale And Held-To-Maturity Securities (Contractual Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value	$ 130,962	[1],[2]
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	260,731	[1],[2]
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	481,314	[1],[2]
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	773,772	[1],[2]
Available-for-sale: Total	1,646,779	[1],[2]
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	55,283	[2]
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	59,433	[2]
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	1,160,049	[2]
Held-to-maturity: Total	1,274,765	[2]	1,312,115
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value	327	[1],[2]
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	1,391	[1],[2]
Available-for-sale: Total	1,718	[1],[2]
State And Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	73,172	[1],[2]
Available-for-sale: Total	73,172	[1],[2]
Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	32,172	[1],[2]
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	186,704	[1],[2]
Available-for-sale: Total	218,876	[1],[2]
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	929,802	[2]
Held-to-maturity: Total	929,802	[2]
Commercial [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value	9,016	[1],[2]
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	41,084	[1],[2]
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	104,357	[1],[2]
Available-for-sale: Total	154,457	[1],[2]
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	59,433	[2]
Held-to-maturity: Total	59,433	[2]
Non-Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	200	[1],[2]
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	29,946	[1],[2]
Available-for-sale: Total	30,146	[1],[2]
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	1,287	[2]
Held-to-maturity: Total	1,287	[2]
Corporate Fixed Income Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value	121,619	[1],[2]
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	251,712	[1],[2]
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	47,955	[1],[2]
Available-for-sale: Total	421,286	[1],[2]
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	55,283	[2]
Held-to-maturity: Total	55,283	[2]	55,329
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	7,428	[1],[2]
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	360,103	[1],[2]
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	379,593	[1],[2]
Available-for-sale: Total	747,124	[1],[2]
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	228,960	[2]
Held-to-maturity: Total	$ 228,960	[2]

[1] Due to the immaterial amount of income recognized on tax-exempt securities, yields were not calculated on a tax equivalent basis.

[2] The weighted average yield is computed using the expected maturity of each security weighted based on the amortized cost of each security.