Composition of Loans, Net of Unearned Income, Broken Out by Portfolio Segment and Class of Financing Receivable (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	$ 10,906,386	[1]	$ 8,946,933	[1]
Software
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	4,102,636		3,261,489
Hardware
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	1,213,032		1,118,370
Venture capital/private equity
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	2,386,054		1,732,699
Life science
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	1,170,220		1,066,199
Premium wine
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	664,834		557,024
Commercial, Other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	396,644		381,195
Total commercial loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	9,933,420		8,116,976
Real estate secured loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	873,255		685,300
Consumer, Other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	99,711		144,657
Total consumer loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	$ 972,966		$ 829,957

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