Employee Compensation and Benefit Plans Expenses Incurred Under Certain Employee Compensation and Benefit Plans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Benefits Disclosure [Line Items]
Incentive Compensation Plans	$ 78,014	$ 66,232	$ 46,467
Direct Drive Incentive Compensation Plan	20,153	22,941	24,556
Retention Program	1,792	2,577	2,076
Warrant Incentive Plan	3,926	5,818	2,523
Deferred Compensation Arrangement with Individual, Compensation Expense	2,458	2,650	1,767
SVBFG 401(k) Plan	11,996	11,277	9,947
SVBFG Employee Stock Ownership Plan	$ 6,691	$ 7,429	$ 10,324