Loans - Non-Covered Loans Modified as TDR (Detail) (Troubled Debt Restructurings Subsequently Defaulted [Member], USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014 Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts	2
Recorded Investment	$ 6,299
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts	1
Recorded Investment	1,669
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts	1
Recorded Investment	$ 4,630