Segment Reporting Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Net interest income	$ 186,998	$ 177,096	$ 170,081	$ 163,169	$ 160,563	$ 154,430	$ 151,934	$ 150,937	$ 697,344		$ 617,864		$ 526,277
(Provision for) reduction of loan losses									(63,693)		(44,330)		(6,101)
Noninterest income	238,713	257,650	98,239	78,604	126,688	69,139	80,426	59,293	673,206		335,546		382,332
Noninterest expense	(168,850)	(160,524)	(143,292)	(149,014)	(143,049)	(135,171)	(135,766)	(132,012)	(621,680)	[1]	(545,998)	[1]	(500,628)	[1]
Income before income tax expense									685,177	[2]	363,082	[2]	401,880	[2]
Total average loans, net of unearned income									9,351,378		7,558,928		5,815,071
Total average assets									23,210,747	[3]	21,311,172	[3]	18,670,499	[3]
Total average deposits									19,619,194		17,910,088		15,568,801
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income									643,016	[4]	595,133	[4]	519,145	[4]
(Provision for) reduction of loan losses									(65,290)	[4]	(45,417)	[4]	(13,494)	[4]
Noninterest income									202,404	[4]	188,842	[4]	150,116	[4]
Noninterest expense									(436,327)	[1],[4]	(398,438)	[1],[4]	(352,458)	[1],[4]
Income before income tax expense									343,803	[2],[4]	340,120	[2],[4]	303,309	[2],[4]
Total average loans, net of unearned income									8,472,045	[4]	6,790,332	[4]	5,111,086	[4]
Total average assets									21,388,037	[3],[4]	19,522,306	[3],[4]	17,103,883	[3],[4]
Total average deposits									19,072,921	[4]	17,575,060	[4]	15,364,804	[4]
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income									26,701		21,807		19,529
(Provision for) reduction of loan losses									1,597		1,087		7,393
Noninterest income									1,209		681		516
Noninterest expense									(15,916)	[1]	(13,651)	[1]	(10,174)	[1]
Income before income tax expense									13,591	[2]	9,924	[2]	17,264	[2]
Total average loans, net of unearned income									919,831		758,471		658,175
Total average assets									959,214	[3]	763,186	[3]	658,797	[3]
Total average deposits									524,398		313,836		186,604
SVB Capital
Segment Reporting Information [Line Items]
Net interest income									20	[4]	15	[4]	10	[4]
(Provision for) reduction of loan losses									0	[4]	0	[4]	0	[4]
Noninterest income									75,037	[4]	27,435	[4]	27,358	[4]
Noninterest expense									(10,737)	[1],[4]	(11,263)	[1],[4]	(13,079)	[1],[4]
Income before income tax expense									64,320	[2],[4]	16,187	[2],[4]	14,289	[2],[4]
Total average loans, net of unearned income									0	[4]	0	[4]	0	[4]
Total average assets									289,328	[3],[4]	239,335	[3],[4]	226,423	[3],[4]
Total average deposits									0	[4]	0	[4]	0	[4]
Other Items
Segment Reporting Information [Line Items]
Net interest income									27,607		909		(12,407)
(Provision for) reduction of loan losses									0		0		0
Noninterest income									394,556		118,588		204,342
Noninterest expense									(158,700)	[1]	(122,646)	[1]	(124,917)	[1]
Income before income tax expense									263,463	[2]	(3,149)	[2]	67,018	[2]
Total average loans, net of unearned income									(40,498)		10,125		45,810
Total average assets									574,168	[3]	786,345	[3]	681,396	[3]
Total average deposits									$ 21,875		$ 21,192		$ 17,393

[1] The Global Commercial Bank segment includes direct depreciation and amortization of $21.3 million, $16.3 million and $12.0 million for 2013, 2012 and 2011, 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 interest for all periods presented. Noncontrolling interest is included within "Other Items".