Recorded Investment in Loans Modified in TDRs within Previous 12 months Subsequently Defaulted (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period	$ 3,600	$ 3,321	$ 3,700	$ 3,321
Commercial loans
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period	2,311	3,321	2,411	3,321
Commercial loans | Software
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period			100
Commercial loans | Hardware
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period	452	3,321	452	3,321
Commercial loans | Premium wine
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period	1,859		1,859
Consumer loans
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period	1,289		1,289
Consumer loans | Other loans
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted in the period	$ 1,289		$ 1,289