Segment Reporting - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment Reporting Information [Line Items]
Net interest income	$ 220,565		$ 177,096		$ 621,858		$ 510,346
(Provision for) loan losses	(16,610)		(10,638)		(19,051)		(35,023)
Noninterest income	80,167		257,650		404,602		434,493
Noninterest expense	(181,989)	[1]	(160,524)	[1]	(527,871)	[1]	(452,830)	[1]
Income before income tax expense	102,133	[2]	263,584	[2]	479,538	[2]	456,986	[2]
Total average loans, net of unearned income	11,439,521		9,545,941		11,098,397		9,086,179
Total average assets	34,598,285	[3]	23,072,734	[3]	31,405,253	[3]	22,496,092	[3]
Total average deposits	29,726,284		19,559,888		26,882,113		18,989,360
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	187,184		162,371		541,375		465,893
(Provision for) loan losses	(16,185)		(11,633)		(18,833)		(36,030)
Noninterest income	57,756		49,991		169,414		144,893
Noninterest expense	(128,685)	[1]	(107,495)	[1]	(374,289)	[1]	(313,080)	[1]
Income before income tax expense	100,070	[2]	93,234	[2]	317,667	[2]	261,676	[2]
Total average loans, net of unearned income	10,192,945		8,576,443		9,917,115		8,175,626
Total average assets	31,809,853	[3]	21,336,583	[3]	28,828,400	[3]	20,732,425	[3]
Total average deposits	28,795,499		18,994,374		26,020,715		18,480,510
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	7,344		6,195		23,529		18,226
(Provision for) loan losses	(425)		995		(218)		1,007
Noninterest income	491		380		1,121		867
Noninterest expense	(2,574)	[1]	(2,484)	[1]	(7,709)	[1]	(6,263)	[1]
Income before income tax expense	4,836	[2]	5,086	[2]	16,723	[2]	13,837	[2]
Total average loans, net of unearned income	1,190,986		942,411		1,120,647		886,679
Total average assets	1,129,947	[3]	998,640	[3]	1,027,707	[3]	910,551	[3]
Total average deposits	877,701		535,611		805,167		493,204
SVB Capital
Segment Reporting Information [Line Items]
Net interest income	12	[4]	1	[4]	55	[4]	5	[4]
(Provision for) loan losses	0	[4]	0	[4]	0	[4]	0	[4]
Noninterest income	1,064	[4]	35,457	[4]	35,617	[4]	48,179	[4]
Noninterest expense	(3,036)	[1],[4]	(2,728)	[1],[4]	(8,815)	[1],[4]	(7,871)	[1],[4]
Income before income tax expense	(1,960)	[2],[4]	32,730	[2],[4]	26,857	[2],[4]	40,313	[2],[4]
Total average loans, net of unearned income	0	[4]	0	[4]	0	[4]	0	[4]
Total average assets	302,949	[3],[4]	329,680	[3],[4]	328,048	[3],[4]	277,136	[3],[4]
Total average deposits	0	[4]	0	[4]	0	[4]	0	[4]
Other Items
Segment Reporting Information [Line Items]
Net interest income	26,025	[5]	8,529	[5]	56,899	[5]	26,222	[5]
(Provision for) loan losses	0	[5]	0	[5]	0	[5]	0	[5]
Noninterest income	20,856	[5]	171,822	[5]	198,450	[5]	240,554	[5]
Noninterest expense	(47,694)	[1],[5]	(47,817)	[1],[5]	(137,058)	[1],[5]	(125,616)	[1],[5]
Income before income tax expense	(813)	[2],[5]	132,534	[2],[5]	118,291	[2],[5]	141,160	[2],[5]
Total average loans, net of unearned income	55,590	[5]	27,087	[5]	60,635	[5]	23,874	[5]
Total average assets	1,355,536	[3],[5]	407,831	[3],[5]	1,221,098	[3],[5]	575,980	[3],[5]
Total average deposits	$ 53,084	[5]	$ 29,903	[5]	$ 56,231	[5]	$ 15,646	[5]

[1] The Global Commercial Bank segment includes direct depreciation and amortization of $5.4 million and $4.9 million for the three months ended September 30, 2014 and 2013, respectively and $15.4 million and $14.0 million for the nine months ended September 30, 2014 and 2013, respectively.

[2] The internal reporting model used by management to assess segment performance does not calculate income tax expense by segment. Our effective tax rate is a reasonable approximation of the segment rates.

[3] Total average assets equal the greater of total average assets or the sum of total liabilities and total stockholders’ equity for each segment.

[4] Global Commercial Bank’s and SVB Capital’s components of net interest income, noninterest income, noninterest expense and total average assets are shown net of noncontrolling interests for all periods presented. Noncontrolling interest is included within "Other Items" as discussed below.

[5] The "Other Items" column reflects the adjustments necessary to reconcile the results of the operating segments to the consolidated financial statements prepared in conformity with GAAP. Noninterest income is primarily attributable to noncontrolling interests and gains on equity warrant assets. Noninterest expense primarily consists of expenses associated with corporate support functions such as finance, human resources, marketing, legal and other expenses. Additionally, average assets primarily consist of cash and cash equivalents and loans from our Community Development Finance practice as part of our responsibilities under the Community Reinvestment Act.