Segment Reporting - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information [Line Items]
Net interest income	$ 177,096		$ 154,430		$ 510,346		$ 457,301
Provision for loan losses	(10,638)		(6,788)		(35,023)		(29,316)
Noninterest income	257,650		69,139		434,493		208,858
Noninterest expense	(160,524)	[1]	(135,171)	[1]	(452,830)		(402,949)
Income before income tax expense	263,584	[2]	81,610	[2]	456,986	[2]	233,894	[2]
Total average loans, net of unearned income	9,545,941		7,907,606		9,086,179		7,318,537
Total average assets	23,072,734	[3]	21,727,197	[3]	22,496,092		20,953,041
Total average deposits	19,559,888		18,260,344		18,989,360		17,547,194
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	162,781	[4]	151,858	[4]	466,303		441,542
Provision for loan losses	(11,633)	[4]	(7,787)	[4]	(36,030)		(29,946)
Noninterest income	50,814	[4]	46,965	[4]	145,716		139,387
Noninterest expense	(109,088)	[1],[4]	(98,064)	[1],[4]	(316,949)		(293,193)
Income before income tax expense	92,874	[2],[4]	92,972	[2],[4]	259,040	[2],[4]	257,790	[2],[4]
Total average loans, net of unearned income	8,683,784	[4]	7,159,609	[4]	8,274,380		6,559,036
Total average assets	21,331,760	[3],[4]	19,860,340	[3],[4]	20,723,037		19,149,134
Total average deposits	18,994,576	[4]	17,881,175	[4]	18,480,757		17,240,715
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	6,195		5,666		18,226		16,147
Provision for loan losses	995		999		1,007		630
Noninterest income	380		149		867		457
Noninterest expense	(3,960)	[1]	(3,603)	[1]	(10,882)		(9,952)
Income before income tax expense	3,610	[2]	3,211	[2]	9,218	[2]	7,282	[2]
Total average loans, net of unearned income	942,411		755,001		886,679		745,069
Total average assets	1,002,718	[3]	758,988	[3]	914,515		749,500
Total average deposits	535,611		341,537		493,204		278,736
SVB Capital
Segment Reporting Information [Line Items]
Net interest income	1	[4]	6	[4]	5		22
Provision for loan losses	0	[4]	0	[4]	0		0
Noninterest income	35,457	[4]	4,330	[4]	48,179		12,474
Noninterest expense	(2,728)	[1],[4]	(3,562)	[1],[4]	(7,871)		(8,970)
Income before income tax expense	32,730	[2],[4]	774	[2],[4]	40,313	[2],[4]	3,526	[2],[4]
Total average loans, net of unearned income	0	[4]	0	[4]	0		0
Total average assets	329,680	[3],[4]	238,595	[3],[4]	277,136		243,124
Total average deposits	0	[4]	0	[4]	0		0
Other Items
Segment Reporting Information [Line Items]
Net interest income	8,119		(3,100)		25,812		(410)
Provision for loan losses	0		0		0		0
Noninterest income	170,999		17,695		239,731		56,540
Noninterest expense	(44,748)	[1]	(29,942)	[1]	(117,128)	[1]	(90,834)	[1]
Income before income tax expense	134,370	[2]	(15,347)	[2]	148,415	[2]	(34,704)	[2]
Total average loans, net of unearned income	(80,254)		(7,004)		(74,880)		14,432
Total average assets	408,576	[3]	869,274	[3]	581,404	[3]	811,283	[3]
Total average deposits	$ 29,701		$ 37,632		$ 15,399		$ 27,743

[1] The Global Commercial Bank segment includes direct depreciation and amortization of $5.6 million and $4.5 million for the three months ended September 30, 2013 and 2012, respectively, and $16.0 million and $11.6 million for the nine months ended September 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.