Loans and Leases (Schedule of Changes in Accretable Discount Related to Credit Impaired Acquired Loans) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Disclosure Loans And Leases Schedule Of Changes In Accretable Discount Related To Credit Impaired Acquired Loans [Abstract]
Balance - beginning of period	$ 43,319,000	$ 49,187,000	$ 46,219,000	$ 62,868,000
Accretion recognized during the period	(2,309,000)	(4,229,000)	(8,042,000)	(16,522,000)
Net reclassification from non-accretable to accretable	0	1,481,000	2,833,000	93,000
Balance - end of period	$ 41,010,000	$ 46,439,000	$ 41,010,000	$ 46,439,000