Investment Securities (Schedule Of Realized Gross Gains And Losses On Sale From Available For Sale Portfolio) (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2015		Dec. 31, 2015
Schedule of Investments [Line Items]
Gross gains on sales of securities		$ 0		$ 0		$ 3,999		$ 284
Gross (losses) on sales of securities		0		0		(2,326)		0
Net gain/(loss) on sales of securities	[1]	0		0		1,673		284
Net OTTI recorded	[2]	(200)		(345)		(200)		(345)
Total securities gain/ (loss), net		(200)		(345)		1,473		(61)
Proceeds from sales		0		0		1,500		300
Debt securities gains/(losses), net						1,700
Available For Sale Securities		4,027,594	[3]	$ 3,673,641	[4]	4,027,594	[3]	$ 3,673,641	[4]	$ 3,929,846
Swap [Member]
Schedule of Investments [Line Items]
Available For Sale Securities		$ 294,000				$ 294,000

[1] There were no sales proceeds for the three months ended September 30, 2016 and 2015; cash proceeds for the nine months ended September 30, 2016 and 2015 were $ 1.5 million and $ .3 million, respectively. Nine months ended September 30, 2016 includes a $ 1.7 million gain from an exchange of approximately $ 294 million of AFS debt securities.

[2] OTTI recorded is related to equity securities.

[3] Includes $ 3.3 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[4] Includes $ 2.9 billion of securities pledged to secure public deposits, securities sold under agreements to repu rchase, and for other purposes .