Loans - Non-Covered Loans Modified as TDR (Detail) (Troubled Debt Restructurings Subsequently Defaulted [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013 Contract	Jun. 30, 2013 Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts	2	13
Recorded Investment	$ 1,828	$ 4,368
Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts	1	1
Recorded Investment	1,297	1,297
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts	1	1
Recorded Investment	531	531
Residential mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts		9
Recorded Investment		2,320
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts		2
Recorded Investment		$ 220