Loans and Leases (Outstanding Principal Balance and the Related Carrying Amount of Acquired Loans) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Loans Individually Evaluated For Impairment [Member]
Acquired Loans Unpaid Principal Balance And Related Carrying Amount [Line Items]
Unpaid principal balance	$ 139,097	$ 176,351
Carrying amount	112,997	138,445
Loans Collectively Evaluated For Impairment [Member]
Acquired Loans Unpaid Principal Balance And Related Carrying Amount [Line Items]
Unpaid principal balance	1,393,362	1,509,870
Carrying amount	1,394,882	1,506,695
Purchased Loan [Member]
Acquired Loans Unpaid Principal Balance And Related Carrying Amount [Line Items]
Unpaid principal balance	1,532,459	1,686,221
Carrying amount	$ 1,507,879	$ 1,645,140