Loans And Leases (Narrative) (Detail) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014 grade		Sep. 30, 2013	Sep. 30, 2014 grade		Sep. 30, 2013
Loans and Leases Receivable Disclosure [Abstract]
Amount of loan pledged as collateral	$ 5,400,000,000	[1]		$ 5,400,000,000	[1]
Interest on non-accrual loans that would have been recorded as additional interest income	3,000,000		3,500,000	7,600,000		10,900,000
Number of Grades	10			10
Write-down of TDR's	$ 2,100,000		$ 3,200,000	$ 10,300,000		$ 17,300,000

[1] Loans and leases include net deferred fees and unamortized premiums of $14.5 million and $13.3 million at September 30, 2014 and December 31, 2013, respectively.