Composition of Loans, Net of Unearned income (Detail) (USD $) In Thousands	Jun. 30, 2011		Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 5,978,646		$ 5,521,737
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	4,937,980	[1]	4,594,777	[1]
Commercial loans | Software
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,034,257		1,820,385
Commercial loans | Hardware
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	645,967		561,610
Commercial loans | Clean technology
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	237,430		159,502
Commercial loans | Venture capital/private equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,009,604		1,036,077
Commercial loans | Life science
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	624,944		568,739
Commercial loans | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	128,232	[2]	144,972	[2]
Commercial loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	257,546		303,492
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	804,581		673,959
Real estate secured loans | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	341,659	[2]	312,255	[2]
Real estate secured loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	462,922	[3]	361,704	[3]
Other loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	198,214		192,823
Other loans | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	37,871		60,178
Premium wine | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 109,500		$ 119,000

[1] Included within our commercial loans portfolio are business credit card loans to commercial clients. At June 30, 2011 and December 31, 2010, our business credit card loans portfolio totaled $42.1 million and $32.5 million, respectively.

[2] Included in our premium wine portfolio are gross construction loans of $109.5 million and $119.0 million at June 30, 2011 and December 31, 2010, respectively.

[3] Consumer loans secured by real estate at June 30, 2011 and December 31, 2010 were comprised of the following: (Dollars in thousands) June 30, 2011 December 31, 2010 Loans for personal residence $ 286,106 $ 189,039 Loans to eligible employees 92,782 88,510 Home equity lines of credit 84,034 84,155 Consumer loans secured by real estate $ 462,922 $ 361,704