Segment Reporting - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Segment Reporting Information [Line Items]
Net interest income	$ 163,169		$ 150,937
(Provision for) reduction of loan losses	(5,813)		(14,529)
Noninterest income	78,604		59,293
Noninterest expense	(149,014)	[1]	(132,012)	[1]
Income before income tax expense	86,946	[2]	63,689	[2]
Total average loans, net of unearned income	8,680,917		6,804,348
Total average assets	22,314,559	[3]	20,232,543	[3]
Total average deposits	18,785,513		16,965,763
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	148,936	[4]	143,264	[4]
(Provision for) reduction of loan losses	(6,207)	[4]	(13,236)	[4]
Noninterest income	46,541	[4]	39,928	[4]
Noninterest expense	(105,578)	[1],[4]	(96,443)	[1],[4]
Income before income tax expense	83,692	[2],[4]	73,513	[2],[4]
Total average loans, net of unearned income	7,868,587	[4]	6,031,356	[4]
Total average assets	20,463,477	[3],[4]	18,556,741	[3],[4]
Total average deposits	18,302,877	[4]	16,702,114	[4]
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	6,104		4,965
(Provision for) reduction of loan losses	394		(1,293)
Noninterest income	234		157
Noninterest expense	(3,461)	[1]	(3,126)	[1]
Income before income tax expense	3,271	[2]	703	[2]
Total average loans, net of unearned income	844,807		737,968
Total average assets	853,932	[3]	741,962	[3]
Total average deposits	470,673		240,500
SVB Capital
Segment Reporting Information [Line Items]
Net interest income	1	[4]	7	[4]
(Provision for) reduction of loan losses	0	[4]	0	[4]
Noninterest income	5,441	[4]	3,587	[4]
Noninterest expense	(2,386)	[1],[4]	(2,536)	[1],[4]
Income before income tax expense	3,056	[2],[4]	1,058	[2],[4]
Total average loans, net of unearned income	0	[4]	0	[4]
Total average assets	238,743	[3],[4]	260,127	[3],[4]
Total average deposits	0	[4]	0	[4]
Other Items
Segment Reporting Information [Line Items]
Net interest income	8,128		2,701
(Provision for) reduction of loan losses	0		0
Noninterest income	26,388		15,621
Noninterest expense	(37,589)	[1]	(29,907)	[1]
Income before income tax expense	(3,073)	[2]	(11,585)	[2]
Total average loans, net of unearned income	(32,477)		35,024
Total average assets	758,407	[3]	673,713	[3]
Total average deposits	$ 11,963		$ 23,149

[1] The Global Commercial Bank segment includes direct depreciation and amortization of $5.0 million and $3.4 million for the three months ended March 31, 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.