Condensed Statements of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Adjustments to reconcile net income to net cash used for operating activities:
(Gains) losses on derivative instruments, net	$ (22,120)	$ (38,681)	$ (9,522)
Gains on investment securities, net	(122,114)	(195,034)	(93,360)
Amortization of share-based compensation	21,861	18,221	13,761
Other, net	6,828	22,469	3,320
Net cash used for operating activities	200,139	166,287	163,228
Cash flows from investing activities:
Net increase in loans	(1,964,250)	(1,429,702)	(983,077)
Net cash used for investing activities	(2,890,399)	(4,038,851)	(5,052,707)
Cash flows from financing activities:
Principal payments of other long term debt	(1,222)	(4,179)	(1,961)
Payments for settlement of 3.875% Convertible Notes	0	(250,000)	0
Proceed from issuance of 5.375% Senior Notes, net of discount and issuance cost	0	0	344,476
Tax benefit from stock exercises	5,581	6,342	4,151
Repurchase of warrant under CPP	0	0	(6,820)
Net cash provided by financing activities	2,584,295	1,911,080	4,453,058
Net (decrease) increase in cash and cash equivalents	(105,965)	(1,961,484)	(436,421)
Cash and cash equivalents at beginning of period	1,114,948	3,076,432	3,512,853
Cash and cash equivalents at end of period	1,008,983	1,114,948	3,076,432
Parent Company
Cash flows from operating activities:
Net income attributable to SVBFG	175,103	171,902	94,951
Adjustments to reconcile net income to net cash used for operating activities:
(Gains) losses on derivative instruments, net	(17,289)	(34,654)	(6,570)
Gains on investment securities, net	(15,329)	(16,432)	(6,923)
Amortization of share-based compensation	21,861	18,221	13,761
Decrease (increase) in other assets	5,463	21,926	24,283
Increase (decrease) in other liabilities	3,952	2,936	10,682
Other, net	2,273	2,510	1,465
Net cash used for operating activities	(40,818)	(42,727)	(12,593)
Cash flows from investing activities:
Net increase in investment securities from purchases, sales and maturities	11,833	(22,821)	(26,773)
Net increase in loans	2,034	(4,211)	2,041
Net cash used for investing activities	39,059	(42,785)	(85,695)
Cash flows from financing activities:
Principal payments of other long term debt	(1,222)	(4,179)	(1,961)
Payments for settlement of 3.875% Convertible Notes	0	(250,000)	0
Proceed from issuance of 5.375% Senior Notes, net of discount and issuance cost	0	0	344,476
Tax benefit from stock exercises	5,581	6,342	4,151
Proceeds from issuance of common stock and ESPP	29,282	36,873	24,019
Repurchase of warrant under CPP	0	0	(6,820)
Net cash provided by financing activities	33,641	(210,964)	363,865
Net (decrease) increase in cash and cash equivalents	31,882	(296,476)	265,577
Cash and cash equivalents at beginning of period	137,185	433,661	168,084
Cash and cash equivalents at end of period	169,067	137,185	433,661
Parent Company | Bank Subsidiaries
Adjustments to reconcile net income to net cash used for operating activities:
Equity in undistributed net income of subsidiary	(195,395)	(189,123)	(130,255)
Cash flows from investing activities:
Investment in subsidiaries	12,180	(12,592)	(18,714)
Parent Company | Nonbank Subsidiaries
Adjustments to reconcile net income to net cash used for operating activities:
Equity in undistributed net income of subsidiary	(21,457)	(20,013)	(13,987)
Cash flows from investing activities:
Investment in subsidiaries	$ 13,012	$ (3,161)	$ (42,249)