Investment Securities - Non-marketable and Other Securities (Detail) $ in Thousands		12 Months Ended
		Dec. 31, 2015 USD ($) Investment	Dec. 31, 2014 USD ($) Investment	Dec. 31, 2013 USD ($) Investment
Investment Holdings [Line Items]
Total non-marketable and other securities	[1],[2]	$ 674,946	$ 1,728,140
Upper Limit
Investment Holdings [Line Items]
Ownership interest percentage		5.00%	5.00%
Fair value accounting
Investment Holdings [Line Items]
Non-marketable securities		$ 548	$ 108,251
Debt Securities | Equity method accounting
Investment Holdings [Line Items]
Non-marketable securities		21,970	26,672
Debt Securities | Equity method accounting | Gold Hill Capital 2008, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 17,453	$ 21,294
Ownership percentage of each Fund		15.50%	15.50%
Debt Securities | Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities		$ 4,517	$ 5,378
Venture capital and private equity fund investments | SVB Strategic Investors Fund II, LP
Investment Holdings [Line Items]
Non-marketable securities		10,035
Venture capital and private equity fund investments | SVB Strategic Investors Fund III, LP
Investment Holdings [Line Items]
Non-marketable securities		23,926
Venture capital and private equity fund investments | SVB Strategic Investors Fund IV, LP
Investment Holdings [Line Items]
Non-marketable securities		26,411
Venture capital and private equity fund investments | Other investments
Investment Holdings [Line Items]
Non-marketable securities		25,333
Venture capital and private equity fund investments | Fair value accounting
Investment Holdings [Line Items]
Non-marketable securities		152,237	1,130,882
Non-marketable securities		233,000	234,000
Venture capital and private equity fund investments | Fair value accounting | SVB Strategic Investors Fund, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 20,794	$ 24,645
Ownership percentage of each Fund		12.60%	12.60%
Venture capital and private equity fund investments | Fair value accounting | SVB Strategic Investors Fund II, LP
Investment Holdings [Line Items]
Non-marketable securities			$ 97,250
Ownership percentage of each Fund		8.60%	8.60%
Venture capital and private equity fund investments | Fair value accounting | SVB Strategic Investors Fund III, LP
Investment Holdings [Line Items]
Non-marketable securities			$ 269,821
Ownership percentage of each Fund		5.90%	5.90%
Venture capital and private equity fund investments | Fair value accounting | SVB Strategic Investors Fund IV, LP
Investment Holdings [Line Items]
Non-marketable securities			$ 291,291
Ownership percentage of each Fund		5.00%	5.00%
Venture capital and private equity fund investments | Fair value accounting | Strategic Investors Fund V Funds
Investment Holdings [Line Items]
Non-marketable securities		$ 0	$ 226,111
Venture capital and private equity fund investments | Fair value accounting | Strategic Investors Fund VI Funds
Investment Holdings [Line Items]
Non-marketable securities		$ 0	$ 89,605
Ownership percentage of each Fund		0.00%	0.00%
Venture capital and private equity fund investments | Fair value accounting | SVB Capital Preferred Return Fund, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 60,619	$ 62,110
Ownership percentage of each Fund		20.00%	20.00%
Venture capital and private equity fund investments | Fair value accounting | SVB Capital-NT Growth Partners, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 62,983	$ 61,973
Ownership percentage of each Fund		33.00%	33.00%
Venture capital and private equity fund investments | Fair value accounting | SVB Capital Partners II, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 0	$ 302
Ownership percentage of each Fund		0.00%	5.10%
Venture capital and private equity fund investments | Fair value accounting | SVB Capital Partners II, LP | Direct ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		1.30%
Venture capital and private equity fund investments | Fair value accounting | SVB Capital Partners II, LP | Indirect ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		3.80%
Venture capital and private equity fund investments | Fair value accounting | Other private equity fund
Investment Holdings [Line Items]
Non-marketable securities		$ 7,841	$ 7,774
Ownership percentage of each Fund		58.20%	58.20%
Venture capital and private equity fund investments | Fair value accounting | Other private equity fund | Direct ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		41.50%
Venture capital and private equity fund investments | Equity method accounting
Investment Holdings [Line Items]
Non-marketable securities		$ 85,705	$ 0
Venture capital and private equity fund investments | Cost method accounting
Investment Holdings [Line Items]
Non-marketable securities		$ 120,676	$ 140,551
Number of investments | Investment		267	281	288
Other venture capital investments | Fair value accounting
Investment Holdings [Line Items]
Non-marketable securities		$ 2,040	$ 71,204
Other venture capital investments | Fair value accounting | SVB Capital Partners II, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 0	$ 20,481
Ownership percentage of each Fund		0.00%	5.10%
Other venture capital investments | Fair value accounting | Silicon Valley BancVentures, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 2,040	$ 3,291
Ownership percentage of each Fund		10.70%	10.70%
Other venture capital investments | Fair value accounting | Capital Partners III, LP
Investment Holdings [Line Items]
Non-marketable securities		$ 0	$ 41,055
Ownership percentage of each Fund		0.00%	0.00%
Other venture capital investments | Fair value accounting | SVB Capital Shanghai Yangpu Venture Capital Fund
Investment Holdings [Line Items]
Non-marketable securities		$ 0	$ 6,377
Ownership percentage of each Fund		0.00%	6.80%
Other investments | Fair value accounting | SVB Capital Preferred Return Fund, LP | Indirect ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		4.10%
Other investments | Fair value accounting | SVB Capital-NT Growth Partners, LP | Indirect ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		12.60%
Other investments | Fair value accounting | Other private equity fund | Direct ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		41.50%
Other investments | Equity method accounting
Investment Holdings [Line Items]
Non-marketable securities		$ 118,532	$ 116,002
Other investments | Equity method accounting | Gold Hill Capital 2008, LP | Direct ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		11.50%
Other investments | Equity method accounting | Gold Hill Capital 2008, LP | Indirect ownership interest
Investment Holdings [Line Items]
Ownership percentage of each Fund		4.00%
Other investments | Equity method accounting | China Joint Venture investment
Investment Holdings [Line Items]
Non-marketable securities		$ 78,799	$ 79,569
Ownership percentage of each Fund		50.00%	50.00%
Other investments | Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities		$ 39,733	$ 36,433
Other investments | Cost method accounting
Investment Holdings [Line Items]
Non-marketable securities		18,882	13,423
Low income housing tax credit funds
Investment Holdings [Line Items]
Tax Credits And Other Tax Benefits Recognized		14,375	12,109	$ 8,762
Non-marketable and other securities		154,356	121,155
Amortization Expense Included In Provision For Income Taxes		$ 10,389	9,340	$ 6,802
Unfunded loan commitments
Investment Holdings [Line Items]
Accrued expenses and other liabilities			$ 65,921

[1] During the second quarter of 2015 we adopted new accounting guidance related to our consolidated variable interest entities (ASU 2015-02). Amounts prior to January 1, 2015 have not been revised for the adoption of this guidance. See Note 2— "Summary of Significant Accounting Policies” of the “Notes to the Consolidated Financial Statements” under Part II, Item 8 of this report for additional details.

[2] Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 2— "Summary of Significant Accounting Policies” of the “Notes to the Consolidated Financial Statements” under Part II, Item 8 of this report for additional details.