Condensed Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009	Dec. 31, 2008
Assets:
Cash and cash equivalents	$ 1,114,948		$ 3,076,432		$ 3,512,853	$ 2,436,725
Investment securities	11,540,486		8,639,487
Net loans	6,880,135		5,439,110
Other assets	376,854		328,187
Total assets	19,968,894		17,527,761
Liabilities and SVBFG stockholders' equity:
Other long-term debt	1,439	[1]	5,257	[1]
Other liabilities	405,321		196,037
Total liabilities	17,718,505		15,779,483
SVBFG stockholders' equity	1,569,392		1,274,350
Total liabilities and total equity	19,968,894		17,527,761
Parent Company
Assets:
Cash and cash equivalents	137,185		433,661		168,084	285,308
Investment securities	235,822		183,929
Net loans	10,903		6,692
Other assets	108,712		101,118
Total assets	1,996,053		1,950,831
Liabilities and SVBFG stockholders' equity:
Other long-term debt	1,439		5,257
Other liabilities	22,057		18,771
Total liabilities	426,661		676,481
SVBFG stockholders' equity	1,569,392		1,274,350
Total liabilities and total equity	1,996,053		1,950,831
Parent Company | 5.375% Senior Notes
Liabilities and SVBFG stockholders' equity:
Notes payable	347,793		347,601
Parent Company | 3.875% Convertible Notes
Liabilities and SVBFG stockholders' equity:
Notes payable			249,304
Parent Company | 7.0% Junior Subordinated Debentures
Liabilities and SVBFG stockholders' equity:
Notes payable	55,372		55,548
Parent Company | Bank Subsidiaries
Assets:
Investment in subsidiaries	1,346,854		1,074,561
Parent Company | Nonbank Subsidiaries
Assets:
Investment in subsidiaries	$ 156,577		$ 150,870

[1] Represents long-term notes payable related to one of our debt fund investments, and was payable beginning April 30, 2009 with the last payment due in April 2012.