Subsequent Events (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				1 Months Ended		3 Months Ended	1 Months Ended			0 Months Ended		1 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 FireEye Inc.	May 07, 2014 FireEye Inc. Subsequent Event	Jun. 30, 2014 Forecast FireEye Inc.	Jun. 30, 2014 Fair value accounting Forecast	May 07, 2014 Fair value accounting Forecast Subsequent Event	May 07, 2014 Non-marketable securities Noncontrolling Interests Fair value accounting Forecast Subsequent Event	May 07, 2014 Non-marketable securities Total SVBFG Stockholders’ Equity Fair value accounting Forecast Subsequent Event	Mar. 04, 2014 FireEye Inc. Fair value accounting	Mar. 02, 2014 FireEye Inc. Fair value accounting	May 09, 2014 FireEye Inc. Fair value accounting Subsequent Event	Mar. 31, 2014 FireEye Inc. Gain (loss) on investment securities, net Fair value accounting
Subsequent Event [Line Items]
Shares received from warrant exercise											309,000
Shares owned (Fund Shares)												5,500,000
Realized pre-tax loss	$ 14,308	$ 8,384											$ 14,000
Accumulated other comprehensive loss	(30,390)		(48,764)											8,200
Change in share price					(53.00%)
Closing stock price	$ 128.78			$ 61.57	$ 28.65	$ 28.65
Gains (losses) on investment securities, net	$ 223,912	$ 27,438					$ 43,000	$ 150,000	$ 121,000	$ 29,000