Segment Reporting - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Segment Reporting Information [Line Items]
Net interest income	$ 170,081		$ 151,934		$ 333,250		$ 302,871
Provision for loan losses	(18,572)		(7,999)		(24,385)		(22,528)
Noninterest income	98,239		80,426		176,843		139,719
Noninterest expense	(143,292)	[1]	(135,766)	[1]	(292,306)		(267,778)
Income before income tax expense	106,456	[2]	88,595	[2]	193,402	[2]	152,284	[2]
Total average loans, net of unearned income	9,022,173		7,237,182		8,852,488		7,020,765
Total average assets	22,093,298	[3]	20,890,876	[3]	22,203,317		20,561,709
Total average deposits	18,614,170		17,407,636		18,699,368		17,186,700
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	154,586	[4]	146,420	[4]	303,522		289,684
Provision for loan losses	(18,190)	[4]	(8,923)	[4]	(24,397)		(22,159)
Noninterest income	48,361	[4]	52,494	[4]	94,902		92,422
Noninterest expense	(102,283)	[1],[4]	(98,686)	[1],[4]	(207,861)		(195,129)
Income before income tax expense	82,474	[2],[4]	91,305	[2],[4]	166,166	[2],[4]	164,818	[2],[4]
Total average loans, net of unearned income	8,203,231	[4]	6,479,544	[4]	8,036,833		6,255,450
Total average assets	20,364,334	[3],[4]	19,022,506	[3],[4]	20,413,630		18,789,624
Total average deposits	18,137,218	[4]	17,131,816	[4]	18,219,590		16,916,965
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	5,927		5,516		12,031		10,481
Provision for loan losses	(382)		924		12		(369)
Noninterest income	253		151		487		308
Noninterest expense	(3,461)	[1]	(3,223)	[1]	(6,922)		(6,349)
Income before income tax expense	2,337	[2]	3,368	[2]	5,608	[2]	4,071	[2]
Total average loans, net of unearned income	871,746		742,130		858,351		740,049
Total average assets	885,259	[3]	747,445	[3]	869,682		744,703
Total average deposits	472,613		253,482		471,648		246,991
SVB Capital
Segment Reporting Information [Line Items]
Net interest income	3	[4]	9	[4]	4		16
Provision for loan losses	0	[4]	0	[4]	0		0
Noninterest income	7,281	[4]	4,557	[4]	12,722		8,144
Noninterest expense	(2,757)	[1],[4]	(2,872)	[1],[4]	(5,143)		(5,408)
Income before income tax expense	4,527	[2],[4]	1,694	[2],[4]	7,583	[2],[4]	2,752	[2],[4]
Total average loans, net of unearned income	0	[4]	0	[4]	0		0
Total average assets	269,771	[3],[4]	251,295	[3],[4]	254,343		254,835
Total average deposits	0	[4]	0	[4]	0		0
Other Items
Segment Reporting Information [Line Items]
Net interest income	9,565		(11)		17,693		2,690
Provision for loan losses	0		0		0		0
Noninterest income	42,344		23,224		68,732		38,845
Noninterest expense	(34,791)	[1]	(30,985)	[1]	(72,380)	[1]	(60,892)	[1]
Income before income tax expense	17,118	[2]	(7,772)	[2]	14,045	[2]	(19,357)	[2]
Total average loans, net of unearned income	(52,804)		15,508		(42,696)		25,266
Total average assets	573,934	[3]	869,630	[3]	665,662	[3]	772,547	[3]
Total average deposits	$ 4,339		$ 22,338		$ 8,130		$ 22,744

[1] The Global Commercial Bank segment includes direct depreciation and amortization of $5.3 million and $3.6 million for the three months ended June 30, 2013 and 2012, respectively, and $10.4 million and $7.0 million for the six months ended June 30, 2013 and 2012, 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 equals 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.