Investment Securities Available for Sale (Schedule Of Unrealized Loss On Investments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 334,089	$ 837,112
Less than 12 Months Unrealized Losses	(3,275)	(2,788)
12 Months or Longer, Fair Value	168,943	1,180
12 Months or Longer Unrealized Losses	(1,359)	(21)
Total Fair Value	503,032	838,292
Total Unrealized Losses	(4,634)	(2,809)
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months Unrealized Losses	0	0
12 Months or Longer, Fair Value	0	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	0	0
Total Unrealized Losses	0	0
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months Unrealized Losses	0	0
12 Months or Longer, Fair Value	0	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	0	0
Total Unrealized Losses	0	0
Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	349,370
Less than 12 Months Unrealized Losses	0	(619)
12 Months or Longer, Fair Value	0	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	0	349,370
Total Unrealized Losses	0	(619)
Mortgage-Backed Securities Issued By U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	3,314	0
Less than 12 Months Unrealized Losses	(8)	0
12 Months or Longer, Fair Value	2	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	3,316	0
Total Unrealized Losses	(8)	0
Mortgage-Backed Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	286,452	148,283
Less than 12 Months Unrealized Losses	(2,229)	(257)
12 Months or Longer, Fair Value	0	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	286,452	148,283
Total Unrealized Losses	(2,229)	(257)
Collateralized Mortgage Obligations Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	42,036	337,060
Less than 12 Months Unrealized Losses	(325)	(1,521)
12 Months or Longer, Fair Value	168,906	297
12 Months or Longer Unrealized Losses	(1,357)	(4)
Total Fair Value	210,942	337,357
Total Unrealized Losses	(1,682)	(1,525)
State And Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	32
Less than 12 Months Unrealized Losses	0	(3)
12 Months or Longer, Fair Value	35	883
12 Months or Longer Unrealized Losses	(2)	(17)
Total Fair Value	35	915
Total Unrealized Losses	(2)	(20)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	2,367
Less than 12 Months Unrealized Losses	0	(388)
12 Months or Longer, Fair Value	0	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	0	2,367
Total Unrealized Losses	0	(388)
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	2,287	0
Less than 12 Months Unrealized Losses	(713)	0
12 Months or Longer, Fair Value	0	0
12 Months or Longer Unrealized Losses	0	0
Total Fair Value	2,287	0
Total Unrealized Losses	$ (713)	$ 0