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, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	18	17
Loans modified in TDRs	$ 34,328	$ 34,275
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	31,028	13,208
Commercial loans | Software
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	2,021	1,142
Commercial loans | Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	20,514	5,183
Commercial loans | Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	2,593	1,949
Commercial loans | Commercial Other Financing Receivable
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	5,900	4,934
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	3,300	21,067
Consumer loans | Real estate secured loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	2,199	17,934
Consumer loans | Consumer Other Financing Receivable
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	$ 1,101	$ 3,133