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	Sep. 30, 2014
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	$ 478,461
SVB Strategic Investors Fund, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	2,250
SVB Strategic Investors Fund II, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	5,589
SVB Strategic Investors Fund III, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	15,641
SVB Strategic Investors Fund IV, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	41,205
Strategic Investors Fund V Funds
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	162,335
Strategic Investors Fund VI Funds
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	239,268
SVB Capital Preferred Return Fund, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	5,886
SVB Capital—NT Growth Partners, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	6,044
Other private equity fund
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	$ 243