Composition of Loans, Net of Unearned income (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 7,789,752	[1]	$ 6,970,082	[1]
Premium wine | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	147,900		110,800
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	6,652,235		5,898,700
Commercial loans | Software
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,752,500		2,492,849
Commercial loans | Hardware
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,086,973		952,303
Commercial loans | Venture capital/private equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,403,801		1,117,419
Commercial loans | Life science
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	917,723		863,737
Commercial loans | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	120,043	[2]	130,245	[2]
Commercial loans | Commercial Other Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	371,195		342,147
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	927,924		879,989
Real estate secured loans | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	373,658	[2]	345,988	[2]
Real estate secured loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	554,266	[3]	534,001	[3]
Other loans | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	33,063		30,256
Other loans | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 176,530		$ 161,137

[1] Included within our total loan portfolio are credit card loans of $58.3 million and $49.7 million at June 30, 2012 and December 31, 2011, respectively.

[2] Included in our premium wine portfolio are gross construction loans of $147.9 million and $110.8 million at June 30, 2012 and December 31, 2011, respectively.

[3] Consumer loans secured by real estate at June 30, 2012 and December 31, 2011 were comprised of the following: (Dollars in thousands) June 30, 2012 December 31, 2011 Loans for personal residence $ 369,780 $ 350,359 Loans to eligible employees 103,824 99,704 Home equity lines of credit 80,662 83,938 Consumer loans secured by real estate $ 554,266 $ 534,001