Investment Securities - Major Components of Investment Securities Portfolio (Parenthetical) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014 Investment		Mar. 31, 2013 Investment		Dec. 31, 2013 Investment
Investment Holdings [Line Items]
Unrealized gain on securities	$ 351,000,000
Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	28,306,000	[1]			32,839,000	[1]
Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	976,922,000	[2]			862,972,000	[2]
Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	144,636,000	[3]			142,883,000	[3]
Cost method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	13,827,000				14,191,000
Cost method accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Number of investments	282		309		288
Recognized other-than-temporary impairment (OTTI) losses	100,000		500,000
Number of other-than-temporary impaired investments	7		16
Non-marketable securities	140,374,000	[4]			148,994,000	[4]
SVB Strategic Investors Fund, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	27,134,000				29,104,000
Percentage of ownership	12.60%		12.60%
SVB Strategic Investors Fund II, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	97,960,000				96,185,000
Percentage of ownership	8.60%		8.60%
SVB Strategic Investors Fund III, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	264,661,000				260,272,000
Percentage of ownership	5.90%		5.90%
SVB Strategic Investors Fund IV, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	291,989,000				226,729,000
Percentage of ownership	5.00%		5.00%
Strategic Investors Fund V Funds | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	159,794,000				118,181,000
Strategic Investors Fund VI Limited Partnership | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	9,871,000				7,944,000
Percentage of ownership	0.20%		0.20%
SVB Capital Preferred Return Fund, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	60,159,000				59,028,000
Percentage of ownership	20.00%		20.00%
SVB Capital—NT Growth Partners, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	61,230,000				61,126,000
Percentage of ownership	33.00%		33.00%
SVB Capital Partners II, LP | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	17,696,000	[5]			22,684,000	[5]
Percentage of ownership	5.10%	[5]	5.10%	[5]
SVB Capital Partners II, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	595,000	[6]			708,000	[6]
Percentage of ownership	5.10%	[6]	5.10%	[6]
SVB Capital Partners II, LP | Fair value accounting | Direct ownership interest | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	1.30%
SVB Capital Partners II, LP | Fair value accounting | Indirect ownership interest | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	3.80%
Other private equity fund | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	3,529,000	[7]			3,695,000	[7]
Percentage of ownership	58.20%	[7]	58.20%	[7]
Other private equity fund | Fair value accounting | Direct ownership interest | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	41.50%
Silicon Valley BancVentures, LP | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	6,520,000				6,564,000
Percentage of ownership	10.70%		10.70%
SVB Capital Shanghai Yangpu Venture Capital Fund | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	4,090,000				3,591,000
Percentage of ownership	6.80%		6.80%
Gold Hill Venture Lending 03, LP | Equity method accounting | Other investments
Investment Holdings [Line Items]
Percentage of ownership	9.30%	[8]	9.30%	[8]
Non-marketable securities	10,380,000	[8]			7,900,000	[8]
Gold Hill Venture Lending 03, LP | Equity method accounting | Direct ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	4.80%
Gold Hill Venture Lending 03, LP | Equity method accounting | Indirect ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	4.50%
Gold Hill Capital 2008, LP | Equity method accounting | Other investments
Investment Holdings [Line Items]
Percentage of ownership	15.50%	[9]	15.50%	[9]
Non-marketable securities	21,076,000	[9]			21,867,000	[9]
Gold Hill Capital 2008, LP | Equity method accounting | Direct ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	11.50%
Gold Hill Capital 2008, LP | Equity method accounting | Indirect ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	4.00%
China Joint Venture investment | Equity method accounting | Other investments
Investment Holdings [Line Items]
Percentage of ownership	50.00%		50.00%
Non-marketable securities	79,765,000				79,940,000
Other investments | Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	33,415,000				33,176,000
Upper Limit | Cost method accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	5.00%		5.00%
Estimated Fair Value | Cost method accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	$ 222,000,000				$ 215,000,000

[1] The following table shows the amounts of other venture capital investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2014 and December 31, 2013 (fair value accounting): March 31, 2014 December 31, 2013(Dollars in thousands) Amount Ownership % Amount Ownership %Silicon Valley BancVentures, LP $6,520 10.7% $6,564 10.7%SVB Capital Partners II, LP (i) 17,696 5.1 22,684 5.1SVB Capital Shanghai Yangpu Venture Capital Fund 4,090 6.8 3,591 6.8Total other venture capital investments $28,306 $32,839 (i)At March 31, 2014, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.

[2] The following table shows the amounts of venture capital and private equity fund investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2014 and December 31, 2013 (fair value accounting): March 31, 2014 December 31, 2013(Dollars in thousands) Amount Ownership % Amount Ownership %SVB Strategic Investors Fund, LP $27,134 12.6% $29,104 12.6%SVB Strategic Investors Fund II, LP 97,960 8.6 96,185 8.6SVB Strategic Investors Fund III, LP 264,661 5.9 260,272 5.9SVB Strategic Investors Fund IV, LP 291,989 5.0 226,729 5.0Strategic Investors Fund V Funds 159,794 Various 118,181 VariousStrategic Investors Fund VI Funds 9,871 0.2 7,944 0.2SVB Capital Preferred Return Fund, LP 60,159 20.0 59,028 20.0SVB Capital—NT Growth Partners, LP 61,230 33.0 61,126 33.0SVB Capital Partners II, LP (i) 595 5.1 708 5.1Other private equity fund (ii) 3,529 58.2 3,695 58.2Total venture capital and private equity fund investments $976,922 $862,972 (i)At March 31, 2014, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.(ii)At March 31, 2014, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.

[3] The following table shows the carrying value and our ownership percentage of each investment at March 31, 2014 and December 31, 2013 (equity method accounting): March 31, 2014 December 31, 2013(Dollars in thousands) Amount Ownership % Amount Ownership %Gold Hill Venture Lending 03, LP (i) $10,380 9.3% $7,900 9.3%Gold Hill Capital 2008, LP (ii) 21,076 15.5 21,867 15.5China Joint Venture investment 79,765 50.0 79,940 50.0Other investments 33,415 Various 33,176 VariousTotal other investments (equity method accounting) $144,636 $142,883

[4] Represents investments in 282 and 288 funds (primarily venture capital funds) at March 31, 2014 and December 31, 2013, respectively, where our ownership interest is typically less than 5% of the voting interests of each such fund and in which we do not have the ability to exercise significant influence over the partnerships operating activities and financial policies. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $140 million, and $222 million, respectively, as of March 31, 2014. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $149 million and $215 million, respectively, as of December 31, 2013.

[5] At March 31, 2014, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.

[6] At March 31, 2014, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.

[7] At March 31, 2014, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.

[8] At March 31, 2014, we had a direct ownership interest of 4.8 percent in the fund and an indirect interest in the fund through our investment in Gold Hill Venture Lending Partners 03, LLC (“GHLLC”) of 4.5 percent.

[9] At March 31, 2014, we had a direct ownership interest of 11.5 percent in the fund and an indirect interest in the fund through our investment in Gold Hill Capital 2008, LLC of 4.0 percent.