Investment Securities (Gross Unrealized Losses And Fair Values By Investment And Length Of Time Of Securities) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	$ 77,472	$ 926,664
Fair Value, 12 Months or More	117,327	131,573
Fair Value Total	194,799	1,058,237
Unrealized Losses, Less than 12 Months	883	27,203
Unrealized Losses, 12 Months or More	24,839	25,920
Unrealized Losses Total	25,722	53,123
U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	997	114,618
Fair Value, 12 Months or More	0	0
Fair Value Total	997	114,618
Unrealized Losses, Less than 12 Months	2	2,883
Unrealized Losses, 12 Months or More	0	0
Unrealized Losses Total	2	2,883
Obligations Of States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	1,306	147,732
Fair Value, 12 Months or More	1,154	6,215
Fair Value Total	2,460	153,947
Unrealized Losses, Less than 12 Months	77	5,483
Unrealized Losses, 12 Months or More	5	503
Unrealized Losses Total	82	5,986
Agency Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	65,235	642,864
Fair Value, 12 Months or More	0	0
Fair Value Total	65,235	642,864
Unrealized Losses, Less than 12 Months	209	17,873
Unrealized Losses, 12 Months or More	0	0
Unrealized Losses Total	209	17,873
Non-Agency Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	7,697	5,664
Fair Value, 12 Months or More	67,070	109,272
Fair Value Total	74,767	114,936
Unrealized Losses, Less than 12 Months	327	124
Unrealized Losses, 12 Months or More	8,561	12,303
Unrealized Losses Total	8,888	12,427
Other Structured Financial Products [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	0	0
Fair Value, 12 Months or More	12,740	12,503
Fair Value Total	12,740	12,503
Unrealized Losses, Less than 12 Months	0	0
Unrealized Losses, 12 Months or More	12,052	12,177
Unrealized Losses Total	12,052	12,177
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	1,645	15,120
Fair Value, 12 Months or More	34,729	1,480
Fair Value Total	36,374	16,600
Unrealized Losses, Less than 12 Months	144	630
Unrealized Losses, 12 Months or More	3,506	300
Unrealized Losses Total	3,650	930
Other Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	592	666
Fair Value, 12 Months or More	1,634	2,103
Fair Value Total	2,226	2,769
Unrealized Losses, Less than 12 Months	124	210
Unrealized Losses, 12 Months or More	715	637
Unrealized Losses Total	$ 839	$ 847