Recorded Investment in Loans Modified in TDRs (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	$ 28,723,000	[1]	$ 13,599,000	[1]
Loans classified as TDRs, charge-offs	14,300,000		2,800,000
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	28,355,000		10,466,000
Commercial loans | Software
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	1,939,000		615,000
Commercial loans | Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	20,514,000		4,018,000
Commercial loans | Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	1,024,000		1,949,000
Commercial loans | Other loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	4,878,000		3,884,000
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	368,000		3,133,000
Consumer loans | Real estate secured loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	368,000		0
Consumer loans | Consumer Other Financing Receivable
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	$ 0		$ 3,133,000

[1] (1)During 2012 and 2011, we had partial charge-offs of $14.3 million and $2.8 million, respectively, on loans classified as TDRs.