Remaining Unfunded Commitments to Venture Capital or Private Equity Funds by our Consolidated Managed Funds (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	$ 377,037
SVB Strategic Investors Fund, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	2,307
SVB Strategic Investors Fund II, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	11,243
SVB Strategic Investors Fund III, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	48,147
SVB Strategic Investors Fund IV, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	114,552
Strategic Investors Fund V Funds
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	153,160
SVB Capital Preferred Return Fund, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	20,299
SVB Capital-NT Growth Partners, LP
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	22,882
Other private equity fund
Commitments and Contingencies Disclosure [Line Items]
Unfunded Commitments	$ 4,447