Remaining Unfunded Commitments to Venture Capital or Private Equity Funds by our Consolidated Managed Funds (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	$ 309,765
SVB Strategic Investors Fund, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	2,311
SVB Strategic Investors Fund II, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	12,145
SVB Strategic Investors Fund III, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	60,040
SVB Strategic Investors Fund IV, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	137,375
SVB Strategic Investors Fund V, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	43,628
SVB Capital Preferred Return Fund, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	23,234
SVB Capital-NT Growth Partners, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	26,373
Other private equity fund
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	$ 4,659