Loans And Leases (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012 D loan_with_modified_structure	Dec. 31, 2011	Dec. 31, 2010
Loans and Leases Receivable Disclosure [Abstract]
Net deferred fees and unamortized premiums	$ 12,700,000	$ 20,600,000
Amount of loan pledged as collateral	3,900,000,000
Loans placed on non-accrual status when past due, days	90
Number of days loans past due become subject to detailed review by Company credit risk team	90
Interest on non-accrual loans that would have been recorded as additional interest income	12,200,000	13,800,000	13,300,000
Interest income recognized on a cash basis	1,700,000	1,800,000	1,900,000
Uncollectible TDRs charged off	45,200,000	21,800,000
Number of loans with an A Note / B Note modified structure	11
Loans receivable with an A Note / B Note structure	39,000,000
B Notes charged off	17,000,000
A Notes charged off	$ 14,000,000