Composition of Loans, Net of Unearned income (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 6,970,082	[1]	$ 5,521,737	[1]
Premium wine | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	110,800		119,000
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	5,898,700		4,594,777
Commercial loans | Software
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,492,849		1,820,680
Commercial loans | Hardware
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	952,303		641,052
Commercial loans | Venture capital/private equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,117,419		1,036,201
Commercial loans | Life science
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	863,737		575,944
Commercial loans | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	130,245	[2]	144,972	[2]
Commercial loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	342,147		375,928
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	879,989		673,959
Real estate secured loans | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	345,988	[2]	312,255	[2]
Real estate secured loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	534,001	[3]	361,704	[3]
Other loans | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	30,256		60,178
Other loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 161,137		$ 192,823

[1] Included within our total loan portfolio are credit card loans of $49.7 million and $32.5 million at December 31, 2011 and 2010, respectively.

[2] Included in our premium wine portfolio are gross construction loans of $110.8 million and $119.0 million at December 31, 2011 and 2010, respectively.

[3] Consumer loans secured by real estate at December 31, 2011 and 2010 were comprised of the following: December 31, (Dollars in thousands) 2011 2010 Loans for personal residences $ 350,359 $ 189,039 Loans to eligible employees 99,704 88,510 Home equity lines of credit 83,938 84,155 Consumer loans secured by real estate $ 534,001 $ 361,704