Summary of Loans Modified in Troubled Debt Restructurings ("TDRs") by Portfolio Segment and Class of Financing Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	$ 25,478	$ 34,275
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	21,667	13,208
Commercial loans | Software
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	769	1,142
Commercial loans | Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	15,272	5,183
Commercial loans | Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	2,135	1,949
Commercial loans | Commercial Other Financing Receivable
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	3,491	4,934
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	3,811	21,067
Consumer loans | Real estate secured loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	2,522	17,934
Consumer loans | Consumer Other Financing Receivable
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	$ 1,289	$ 3,133