Investment Securities (Schedule Of Investments Within The Available For Sale Portfolio That Had Unrealized Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 1,782,008	$ 349,413
Less than 12 months, Unrealized Losses	(47,083)	(1,391)
12 months or longer, Fair Value	77,904	0
12 months or longer, Unrealized Losses	(4,315)	0
Total Fair Value	1,859,912	349,413
Total Unrealized Losses	(51,398)	(1,391)
Collateralized Mortgage Obligations [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	1,637,064	305,318
Less than 12 months, Unrealized Losses	(43,221)	(1,010)
12 months or longer, Fair Value	77,904	0
12 months or longer, Unrealized Losses	(4,315)	0
Total Fair Value	1,714,968	305,318
Total Unrealized Losses	(47,536)	(1,010)
Mortgage Backed Securities Issued By U S Government Sponsored Enterprises [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	144,901	44,095
Less than 12 months, Unrealized Losses	(3,839)	(381)
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Total Fair Value	144,901	44,095
Total Unrealized Losses	(3,839)	(381)
Total debt securities
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	1,781,965
Less than 12 months, Unrealized Losses	(47,060)
12 months or longer, Fair Value	77,904
12 months or longer, Unrealized Losses	(4,315)
Total Fair Value	1,859,869
Total Unrealized Losses	(51,375)
Equity Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	43
Less than 12 months, Unrealized Losses	(23)
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Total Fair Value	43
Total Unrealized Losses	$ (23)