Loans and Allowance for Loan Losses - Carrying Amounts at Acquisition of All Purchased Loans (Impaired and Non-Impaired) Acquired (Detail) (Acquired Loans [Member], Annapolis Bancorp Inc. And PVF Capital Corp. [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required cash flows at acquisition	$ 837,086
Non-accretable difference (expected losses and foregone interest)	(76,199)
Cash flows expected to be collected at acquisition	760,887
Accretable yield	(115,352)
Basis in acquired loans at acquisition	645,535
Impaired Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required cash flows at acquisition	40,972
Non-accretable difference (expected losses and foregone interest)	(23,207)
Cash flows expected to be collected at acquisition	17,765
Accretable yield	(2,505)
Basis in acquired loans at acquisition	15,260
Performing Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required cash flows at acquisition	796,114
Non-accretable difference (expected losses and foregone interest)	(52,992)
Cash flows expected to be collected at acquisition	743,122
Accretable yield	(112,847)
Basis in acquired loans at acquisition	$ 630,275