Loans And Leases (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013 grade	Sep. 30, 2012	Sep. 30, 2013 loan loan_with_modified_structure grade	Sep. 30, 2012
Loans and Leases Receivable Disclosure [Abstract]
Amount of loan pledged as collateral	$ 4,900,000,000		$ 4,900,000,000
Interest on non-accrual loans that would have been recorded as additional interest income	3,500,000	4,700,000	10,900,000	10,600,000
Interest income recognized on a cash basis	900,000	300,000	2,800,000	1,000,000
Number of Grades	10		10
Write-down of TDR's	(3,200,000)	(10,200,000)	(17,300,000)	(33,800,000)
Number of loans with two tier modified structure			11
Loans receivable with an A Note / B Note structure			37,400,000
B Notes charged off			17,300,000
Number of Loans with TDR Classification Removed			2
TDR classification removed			$ 13,500,000
Number of loans with two tier modified structure in accrual status			8