Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Remaining Unfunded Commitments to Venture Capital or Private Equity Funds by our Consolidated Managed Funds (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	$ 448,482
SVB Strategic Investors Fund, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	2,298
SVB Strategic Investors Fund II, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	8,475
SVB Strategic Investors Fund III, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	33,462
SVB Strategic Investors Fund IV, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	83,897
Strategic Investors Fund V Funds
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	282,046
Strategic Investors Fund VI Funds
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	3,500
SVB Capital Preferred Return Fund, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	14,286
SVB Capital—NT Growth Partners, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	16,289
Other private equity fund
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	$ 4,229