Loans and Allowance for Loan Losses Composition of Loans, Net of Unearned income (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 10,906,386	[1]	$ 8,946,933	[1]
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,418,991		1,098,813
Software
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	4,102,636		3,261,489
Hardware
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,213,032		1,118,370
Venture capital/private equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,386,054		1,732,699
Life science
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,170,220		1,066,199
Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	664,834		557,024
Premium wine | Non-real Estate Secured Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	149,841		143,511
Premium wine | Real Estate Secured Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	514,993	[2]	413,513	[2]
Commercial, Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	396,644		381,195
Commercial, Other | Construction Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	76,997		65,742
Commercial, Other | Commercial Loans Receivable excluding Construction and Real Estate Secured
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	288,904		315,453
Real estate, Other | Real Estate Secured Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	30,743		0
Consumer, Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	99,711		144,657
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	873,255		685,300
Real estate secured loans | Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	873,255	[3]	685,300	[3]
Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	972,966		829,957
Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	9,933,420		8,116,976
Total commercial loans | Commercial Loans Receivable excluding Construction and Real Estate Secured
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 9,310,687		$ 7,637,721

[1] Included within our total loan portfolio are credit card loans of $85 million and $64 million at December 31, 2013 and 2012, respectively.

[2] Included in our premium wine portfolio are gross construction loans of $112 million and $148 million at December 31, 2013 and 2012, respectively.

[3] Consumer loans secured by real estate at December 31, 2013 and 2012 were comprised of the following: December 31,(Dollars in thousands) 2013 2012Loans for personal residence $685,327 $503,378Loans to eligible employees 121,548 110,584Home equity lines of credit 66,380 71,338Consumer loans secured by real estate $873,255 $685,300