Investment Securities (Expected Maturities Of Investment Securities Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investment Securities [Abstract]
Available-for-sale, Maturity, Within one year, Amortized Cost	$ 30,284	$ 79,212
Available-for-sale, Maturity, One to five years, Amortized Cost	111,294	123,174
Available-for-sale, Maturity, Five to ten years, Amortized Cost	651,094	240,215
Available-for-sale, Maturity, Beyond ten years, Amortized Cost	1,644,097	1,588,200
Available-for-sale, Amortized Cost	2,436,769	2,030,801
Held-to-maturity, Maturity, Within one year, Amortized Cost	3,066	4,075
Held-to-maturity, Maturity, One to five years, Amortized Cost	2,355	4,819
Held-to-maturity, Maturity, Five to ten years, Amortized Cost	144,701	151,395
Held-to-maturity, Maturity, Beyond ten years, Amortized Cost	252,706	324,301
Held-to-maturity, Amortized Cost	402,828	484,590
Available-for-sale, Maturity, Within one year, Fair Value	30,544	79,668
Available-for-sale, Maturity, One to five years, Fair Value	116,982	127,761
Available-for-sale, Maturity, Five to ten years, Fair Value	665,199	252,434
Available-for-sale, Maturity, Beyond ten years, Fair Value	1,688,059	1,611,413
Available-for-sale, Fair Value	2,500,784	2,071,276
Held-to-maturity, Maturity, Within one year, Fair Value	3,066	4,073
Held-to-maturity, Maturity, One to five years, Fair Value	2,427	4,861
Held-to-maturity, Maturity, Five to ten years, Fair Value	153,882	158,366
Held-to-maturity, Maturity, Beyond ten years, Fair Value	273,826	340,399
Held-to-maturity, Fair Value	$ 433,201	$ 507,699
Available-for-sale, Maturity, Within one year, Weighted Average Yield	3.19%	1.61%
Available-for-sale, Maturity, One to five years, Weighted Average Yield	3.33%	3.38%
Available-for-sale, Maturity, Five to ten years, Weighted Average Yield	2.48%	3.86%
Available-for-sale, Maturity, Beyond ten years, Weighted Average Yield	3.17%	3.32%
Available-for-sale, Weighted Average Yield	2.99%	3.32%
Held-to-maturity, Maturity, Within one year, Weighted Average Yield	2.25%	1.48%
Held-to-maturity, Maturity, One to five years, Weighted Average Yield	3.35%	2.60%
Held-to-maturity, Maturity, Five to ten years, Weighted Average Yield	2.94%	2.97%
Held-to-maturity, Maturity, Beyond ten years, Weighted Average Yield	4.48%	4.47%
Held-to-maturity, Weighted Average Yield	3.90%	3.96%