Recorded Investment in Loans Modified in TDRs (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	$ 1,969	[1]	$ 3,429	[1]	$ 16,431	[1]	$ 11,177	[1]
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	1,969		3,429		16,039		7,855
Commercial loans | Software
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	1,969		381		1,969		941
Commercial loans | Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		801		11,677		2,674
Commercial loans | Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		0		156		1,993
Commercial loans | Other loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		2,247		2,237		2,247
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		0		392		3,322
Consumer loans | Real estate secured loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		0		392		0
Consumer loans | Consumer Other Financing Receivable
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	$ 0		$ 0		$ 0		$ 3,322

[1] (1)During the three and nine months ended September 30, 2012, we had partial charge-offs of $1.1 million and $11.0 million, respectively, on loans classified as TDRs. There were $0.6 million partial charge-offs on loans classified as TDRs during the three and nine months ended September 30, 2011.