Investment Securities (Schedule Of Unrealized Loss On Investments) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 2,011,070	$ 334,089
Less than 12 Months, Unrealized Losses	33,603	3,275
12 Months or Longer, Fair Value	8,850	168,943
12 Months or Longer, Unrealized Losses	709	1,359
Total Fair Value, Fair Value	2,019,920	503,032
Total Fair Value, Unrealized Losses	34,312	4,634
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, Fair Value	0	0
Total Fair Value, Unrealized Losses	0	0
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	14,301	0
Less than 12 Months, Unrealized Losses	229	0
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total Fair Value, Fair Value	14,301	0
Total Fair Value, Unrealized Losses	229	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	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, Fair Value	0	0
Total Fair Value, Unrealized Losses	0	0
Mortgage-Backed Securities Issued By U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	123,112	3,314
Less than 12 Months, Unrealized Losses	2,134	8
12 Months or Longer, Fair Value	6,251	2
12 Months or Longer, Unrealized Losses	269	0
Total Fair Value, Fair Value	129,363	3,316
Total Fair Value, Unrealized Losses	2,403	8
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	1,736,306	286,452
Less than 12 Months, Unrealized Losses	27,637	2,229
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total Fair Value, Fair Value	1,736,306	286,452
Total Fair Value, Unrealized Losses	27,637	2,229
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	137,351	42,036
Less than 12 Months, Unrealized Losses	3,603	325
12 Months or Longer, Fair Value	0	168,906
12 Months or Longer, Unrealized Losses	0	1,357
Total Fair Value, Fair Value	137,351	210,942
Total Fair Value, Unrealized Losses	3,603	1,682
State And Municipal 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	37	35
12 Months or Longer, Unrealized Losses	2	2
Total Fair Value, Fair Value	37	35
Total Fair Value, Unrealized Losses	2	2
Equity 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, Fair Value	0	0
Total Fair Value, Unrealized Losses	0	0
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	0	2,287
Less than 12 Months, Unrealized Losses	0	713
12 Months or Longer, Fair Value	2,562	0
12 Months or Longer, Unrealized Losses	438	0
Total Fair Value, Fair Value	2,562	2,287
Total Fair Value, Unrealized Losses	$ 438	$ 713