Segment Reporting - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Net interest income	$ 204,965	$ 170,081	$ 401,293	$ 333,250
(Provision for) loan losses	(1,947)	(18,572)	(2,441)	(24,385)
Noninterest income	14,210	98,239	324,435	176,843
Noninterest expense	(173,446)	(143,292)	(345,882)	(292,306)
Income before income tax expense	43,782	106,456	377,405	193,402
Total average loans, net of unearned income	11,080,602	9,022,173	10,925,007	8,852,488
Total average assets	31,745,630	22,093,298	29,767,621	22,203,317
Total average deposits	27,177,125	18,614,170	25,436,457	18,699,368
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	178,488	154,586	354,191	303,522
(Provision for) loan losses	(1,841)	(18,190)	(2,648)	(24,397)
Noninterest income	53,021	48,361	111,658	94,902
Noninterest expense	(123,679)	(101,246)	(245,604)	(205,585)
Income before income tax expense	105,989	83,511	217,597	168,442
Total average loans, net of unearned income	9,971,725	8,203,231	9,867,841	8,036,833
Total average assets	29,218,349	20,442,613	27,405,141	20,491,451
Total average deposits	26,324,070	18,137,218	24,610,629	18,219,590
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	9,293	5,927	16,185	12,031
(Provision for) loan losses	(106)	(382)	207	12
Noninterest income	356	253	630	487
Noninterest expense	(2,640)	(1,848)	(5,135)	(3,779)
Income before income tax expense	6,903	3,950	11,887	8,751
Total average loans, net of unearned income	1,119,503	871,746	1,084,894	858,351
Total average assets	985,225	881,298	974,853	865,777
Total average deposits	791,261	472,613	768,300	471,648
SVB Capital
Segment Reporting Information [Line Items]
Net interest income	29	3	43	4
(Provision for) loan losses	0	0	0	0
Noninterest income	(3,119)	7,281	34,553	12,722
Noninterest expense	(3,144)	(2,757)	(5,779)	(5,143)
Income before income tax expense	(6,234)	4,527	28,817	7,583
Total average loans, net of unearned income	0	0	0	0
Total average assets	342,924	269,771	342,451	254,343
Total average deposits	0	0	0	0
Other Items (2)
Segment Reporting Information [Line Items]
Net interest income	17,155	9,565	30,874	17,693
(Provision for) loan losses	0	0	0	0
Noninterest income	(36,048)	42,344	177,594	68,732
Noninterest expense	(43,983)	(37,441)	(89,364)	(77,799)
Income before income tax expense	(62,876)	14,468	119,104	8,626
Total average loans, net of unearned income	(10,626)	(52,804)	(27,728)	(42,696)
Total average assets	1,199,132	499,616	1,045,176	591,746
Total average deposits	$ 61,794	$ 4,339	$ 57,528	$ 8,130