Condensed Statements of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income attributable to SVBFG	$ 171,902	$ 94,951	$ 48,010
Adjustments to reconcile net income to net cash used for operating activities:
(Gains) losses on derivative instruments, net	(38,681)	(9,522)	753
(Gains) losses on investment securities, net	(195,034)	(93,360)	31,209
Amortization of share-based compensation	18,221	13,761	14,784
Other, net	21,833	2,893	(3,969)
Net cash used for operating activities	166,287	163,228	86,963
Cash flows from investing activities:
Net (increase) decrease in loans	(1,429,702)	(983,077)	849,570
Net cash used for investing activities	(4,038,851)	(5,052,707)	(1,857,466)
Cash flows from financing activities:
Principal payments of other long-term debt	(4,179)	(1,961)	(102,578)
Payments for settlement of 3.875% Convertible Notes	(250,000)
Proceeds from issuance of 5.375% Senior Notes, net of discount and issuance cost		344,476
Tax benefit from stock exercises	6,342	4,151	458
Dividends paid on preferred stock			(12,110)
Proceeds from issuance of common stock and ESPP	36,873	24,019	5,873
Proceeds from the issuance of common stock under our public equity offering, net of issuance costs			292,107
Redemption of preferred stock under the CPP			(235,000)
Repurchase of warrant under CPP		(6,820)
Net cash provided by financing activities	1,911,080	4,453,058	2,846,631
Net (decrease) increase in cash and cash equivalents	(1,961,484)	(436,421)	1,076,128
Cash and cash equivalents at beginning of year	3,076,432	3,512,853	2,436,725
Cash and cash equivalents at end of year	1,114,948	3,076,432	3,512,853
Parent Company
Cash flows from operating activities:
Net income attributable to SVBFG	171,902	94,951	48,010
Adjustments to reconcile net income to net cash used for operating activities:
(Gains) losses on derivative instruments, net	(34,654)	(6,570)	200
(Gains) losses on investment securities, net	(16,432)	(6,923)	1,319
Amortization of share-based compensation	18,221	13,761	14,784
Decrease (increase) in other assets	21,926	24,283	(21,494)
Increase (decrease) in other liabilities	2,936	10,682	(2,578)
Other, net	2,510	1,465	12,373
Net cash used for operating activities	(42,727)	(12,593)	(46,417)
Cash flows from investing activities:
Net increase in investment securities from purchases, sales and maturities	(22,821)	(26,773)	(11,455)
Net (increase) decrease in loans	(4,211)	2,041	25,304
Net cash used for investing activities	(42,785)	(85,695)	(122,135)
Cash flows from financing activities:
Principal payments of other long-term debt	(4,179)	(1,961)
Payments for settlement of 3.875% Convertible Notes	(250,000)
Proceeds from issuance of 5.375% Senior Notes, net of discount and issuance cost		344,476
Tax benefit from stock exercises	6,342	4,151	458
Dividends paid on preferred stock			(12,110)
Proceeds from issuance of common stock and ESPP	36,873	24,019	5,873
Proceeds from the issuance of common stock under our public equity offering, net of issuance costs			292,107
Redemption of preferred stock under the CPP			(235,000)
Repurchase of warrant under CPP		(6,820)
Net cash provided by financing activities	(210,964)	363,865	51,328
Net (decrease) increase in cash and cash equivalents	(296,476)	265,577	(117,224)
Cash and cash equivalents at beginning of year	433,661	168,084	285,308
Cash and cash equivalents at end of year	137,185	433,661	168,084
Parent Company | Bank Subsidiaries
Adjustments to reconcile net income to net cash used for operating activities:
Equity in undistributed net income of subsidiary	(187,055)	(126,706)	(97,770)
Cash flows from investing activities:
Investment in subsidiaries	(18,698)	(15,553)	(110,326)
Parent Company | Nonbank Subsidiaries
Adjustments to reconcile net income to net cash used for operating activities:
Equity in undistributed net income of subsidiary	(22,081)	(17,536)	(1,261)
Cash flows from investing activities:
Investment in subsidiaries	$ 2,945	$ (45,410)	$ (25,658)