Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Total Capital Commitments, Unfunded Capital Commitments, and Our Ownership in Each Fund (Details) $ in Millions	3 Months Ended
	Sep. 30, 2021 USD ($)
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	$ 3
Parent Company
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	424
SVBFG Unfunded Commitments	15
Parent Company | CP II, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	1
SVBFG Unfunded Commitments	$ 0
SVBFG Ownership of each Fund	5.10%
Parent Company | Strategic Investors Fund II, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	$ 15
SVBFG Unfunded Commitments	$ 1
SVBFG Ownership of each Fund	8.60%
Parent Company | Strategic Investors Fund III, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	$ 15
SVBFG Unfunded Commitments	$ 1
SVBFG Ownership of each Fund	5.90%
Parent Company | Strategic Investors Fund IV, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	$ 12
SVBFG Unfunded Commitments	$ 2
SVBFG Ownership of each Fund	5.00%
Parent Company | Strategic Investors Fund V funds
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	$ 1
SVBFG Unfunded Commitments	0
Parent Company | Other venture capital and private equity fund investments
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	11
SVBFG Unfunded Commitments	3
Parent Company | Debt funds (equity method accounting)
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	59
SVBFG Unfunded Commitments	0
Parent Company | Other fund investments
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	257
SVBFG Unfunded Commitments	6
Parent Company | Capital Preferred Return Fund, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	13
SVBFG Unfunded Commitments	$ 0
SVBFG Ownership of each Fund	20.00%
Parent Company | Growth Partners, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	$ 25
SVBFG Unfunded Commitments	$ 1
SVBFG Ownership of each Fund	33.00%
Parent Company | Strategic Investors Fund, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	$ 15
SVBFG Unfunded Commitments	$ 1
SVBFG Ownership of each Fund	12.60%