Available-For-Sale And Held-To-Maturity Securities (Narrative) (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013 security		Sep. 30, 2012		Sep. 30, 2013 security		Sep. 30, 2012		Dec. 31, 2012
AvailableForSaleMortgageBackedSecuritiesTransferredToHeldToMaturity					$ 1,100,000,000
Carrying value of securities pledged as collateral	539,900,000				539,900,000				613,800,000
Available-for-sale Securities	1,231,571,000				1,231,571,000				1,625,168,000
Available-for-sale Securities, Amortized cost	1,236,110,000				1,236,110,000				1,601,102,000
Gross unrealized losses related to all other securities	18,147,000	[1]			18,147,000	[1]			3,394,000	[1]
Unrealized gains on available-for-sale securities, net of tax	(8,160,000)	[2]	8,356,000	[2]	(48,158,000)	[2]	12,714,000	[2]
Realized gains resulted from sale of available-for-sale securities	200,000				1,700,000
Proceeds from sale of available-for-sale securities	4,500,000		92,400,000		194,100,000		186,500,000
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	79				79
Available-for-sale securities related to individual securities, number of positions	79				79
Available-For-Sale Securities [Member]
Available-for-sale Securities	556,800,000,000				556,800,000,000
Available-for-sale securities, percentage of investment portfolio	45.20%				45.20%
Available-for-sale Securities, Amortized cost	574,900,000,000				574,900,000,000
Gross unrealized losses related to all other securities	$ 18,100,000				$ 18,100,000

[1] Unrealized gains/(losses) related to available-for-sale securities are reported in accumulated other comprehensive income.

[2] Net of taxes of $5.4 million and $5.2 million for the three months ended September 30, 2013 and 2012, respectively, and $29.6 million and $7.9 million for the nine months ended September 30, 2013 and 2012, respectively.Amounts are net of reclassifications to earnings of realized gains of $0.2 million and $0.4 million for the three months ended September 30, 2013 and 2012, respectively. Amounts are net of reclassifications to earnings of realized gains of $1.1 million and $1.6 million for the nine months ended September 30, 2013 and 2012, respectively.