Summary of Loans Modified in Troubled Debt Restructurings ("TDRs") by Portfolio Segment and Class of Financing Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	$ 34,275
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	13,208
Commercial loans | Software
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	1,142
Commercial loans | Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	5,183
Commercial loans | Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	1,949
Commercial loans | Other
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	4,934
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	21,067
Consumer loans | Real estate secured loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	17,934
Consumer loans | Other
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	$ 3,133