Investment Securities (Summary Of Amount Of Gross Unrealized Losses For Debt Securities And Estimated Fair Value) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	$ 1,713	$ 3,414
Available-for-sale, Less than 12 months - Estimated fair value	155,718	369,616
Available-for-sale, 12 months or more - Gross unrealized losses	882,299	921,919
Available-for-sale, 12 months or more - Estimated fair value	921,565	965,952
Available-for-sale, Total - Gross unrealized losses	884,012	925,333
Available-for-sale, Total - Estimated fair value	1,077,283	1,335,568
Municipal Securities [Member]
Investment [Line Items]
Held-to-maturity, Less than 12 months - Gross unrealized losses	225	415
Held-to-maturity, Less than 12 months - Estimated fair value	11,399	10,855
Held-to-maturity, 12 months or more - Gross unrealized losses	210	668
Held-to-maturity, 12 months or more - Estimated fair value	14,646	22,188
Held-to-maturity, Total - Gross unrealized losses	435	1,083
Held-to-maturity, Total - Estimated fair value	26,045	33,043
Available-for-sale, Less than 12 months - Gross unrealized losses	169	1,305
Available-for-sale, Less than 12 months - Estimated fair value	5,420	15,011
Available-for-sale, 12 months or more - Gross unrealized losses	2,216	395
Available-for-sale, 12 months or more - Estimated fair value	11,478	4,023
Available-for-sale, Total - Gross unrealized losses	2,385	1,700
Available-for-sale, Total - Estimated fair value	16,898	19,034
Agency Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	54	60
Available-for-sale, Less than 12 months - Estimated fair value	21,836	13,308
Available-for-sale, 12 months or more - Gross unrealized losses	84	62
Available-for-sale, 12 months or more - Estimated fair value	7,168	3,880
Available-for-sale, Total - Gross unrealized losses	138	122
Available-for-sale, Total - Estimated fair value	29,004	17,188
Agency Guaranteed Mortgage-Backed Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	48	102
Available-for-sale, Less than 12 months - Estimated fair value	11,668	52,267
Available-for-sale, 12 months or more - Gross unrealized losses	2	0
Available-for-sale, 12 months or more - Estimated fair value	241	0
Available-for-sale, Total - Gross unrealized losses	50	102
Available-for-sale, Total - Estimated fair value	11,909	52,267
Small Business Administration Loan-Backed Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	235	1,783
Available-for-sale, Less than 12 months - Estimated fair value	56,975	260,865
Available-for-sale, 12 months or more - Gross unrealized losses	1,725	2,713
Available-for-sale, 12 months or more - Estimated fair value	165,355	191,339
Available-for-sale, Total - Gross unrealized losses	1,960	4,496
Available-for-sale, Total - Estimated fair value	222,330	452,204
Mutual Funds And Other [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	18	6
Available-for-sale, Less than 12 months - Estimated fair value	20,053	167
Available-for-sale, 12 months or more - Gross unrealized losses	0	0
Available-for-sale, 12 months or more - Estimated fair value	0	0
Available-for-sale, Total - Gross unrealized losses	18	6
Available-for-sale, Total - Estimated fair value	20,053	167
Held-To-Maturity [Member]
Investment [Line Items]
Held-to-maturity, Less than 12 months - Gross unrealized losses	225	420
Held-to-maturity, Less than 12 months - Estimated fair value	11,399	10,950
Held-to-maturity, 12 months or more - Gross unrealized losses	128,734	130,654
Held-to-maturity, 12 months or more - Estimated fair value	171,224	179,605
Held-to-maturity, Total - Gross unrealized losses	128,959	131,074
Held-to-maturity, Total - Estimated fair value	182,623	190,555
Available-for-sale Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	1,695	3,408
Available-for-sale, Less than 12 months - Estimated fair value	135,665	369,449
Available-for-sale, 12 months or more - Gross unrealized losses	882,299	921,919
Available-for-sale, 12 months or more - Estimated fair value	921,565	965,952
Available-for-sale, Total - Gross unrealized losses	883,994	925,327
Available-for-sale, Total - Estimated fair value	1,057,230	1,335,401
Asset-Backed Securities [Member] | Trust Preferred Securities - Banks And Insurance [Member]
Investment [Line Items]
Held-to-maturity, Less than 12 months - Gross unrealized losses	0	0
Held-to-maturity, Less than 12 months - Estimated fair value	0	0
Held-to-maturity, 12 months or more - Gross unrealized losses	117,109	118,737
Held-to-maturity, 12 months or more - Estimated fair value	145,346	144,053
Held-to-maturity, Total - Gross unrealized losses	117,109	118,737
Held-to-maturity, Total - Estimated fair value	145,346	144,053
Available-for-sale, Less than 12 months - Gross unrealized losses	1,162	0
Available-for-sale, Less than 12 months - Estimated fair value	37,728	0
Available-for-sale, 12 months or more - Gross unrealized losses	842,857	880,509
Available-for-sale, 12 months or more - Estimated fair value	706,134	695,365
Available-for-sale, Total - Gross unrealized losses	844,019	880,509
Available-for-sale, Total - Estimated fair value	743,862	695,365
Asset-Backed Securities [Member] | Other [Member]
Investment [Line Items]
Held-to-maturity, Less than 12 months - Gross unrealized losses	0	0
Held-to-maturity, Less than 12 months - Estimated fair value	0	0
Held-to-maturity, 12 months or more - Gross unrealized losses	11,415	11,249
Held-to-maturity, 12 months or more - Estimated fair value	11,232	13,364
Held-to-maturity, Total - Gross unrealized losses	11,415	11,249
Held-to-maturity, Total - Estimated fair value	11,232	13,364
Available-for-sale, Less than 12 months - Gross unrealized losses	0	0
Available-for-sale, Less than 12 months - Estimated fair value	0	0
Available-for-sale, 12 months or more - Gross unrealized losses	9,435	15,302
Available-for-sale, 12 months or more - Estimated fair value	15,701	18,585
Available-for-sale, Total - Gross unrealized losses	9,435	15,302
Available-for-sale, Total - Estimated fair value	15,701	18,585
Asset-Backed Securities [Member] | Other Debt Securities [Member]
Investment [Line Items]
Held-to-maturity, Less than 12 months - Gross unrealized losses		5
Held-to-maturity, Less than 12 months - Estimated fair value		95
Held-to-maturity, 12 months or more - Gross unrealized losses		0
Held-to-maturity, 12 months or more - Estimated fair value		0
Held-to-maturity, Total - Gross unrealized losses		5
Held-to-maturity, Total - Estimated fair value		95
Asset-Backed Securities [Member] | Trust Preferred Securities - Real Estate Investment Trusts [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	0	0
Available-for-sale, Less than 12 months - Estimated fair value	0	0
Available-for-sale, 12 months or more - Gross unrealized losses	25,930	21,614
Available-for-sale, 12 months or more - Estimated fair value	14,431	18,645
Available-for-sale, Total - Gross unrealized losses	25,930	21,614
Available-for-sale, Total - Estimated fair value	14,431	18,645
Asset-Backed Securities [Member] | Auction Rate Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	27	158
Available-for-sale, Less than 12 months - Estimated fair value	2,038	27,998
Available-for-sale, 12 months or more - Gross unrealized losses	50	1,324
Available-for-sale, 12 months or more - Estimated fair value	1,057	34,115
Available-for-sale, Total - Gross unrealized losses	77	1,482
Available-for-sale, Total - Estimated fair value	$ 3,095	$ 62,113