Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interests	$ 519,178	$ 390,266	$ 374,820
Change in cumulative translation gains (losses):
Foreign currency translation gains (losses)	6,355	(5,245)	2,570
Related tax (expense) benefit	(2,587)	2,050	(957)
Change in unrealized (losses) gains on available-for-sale securities:
Unrealized holding (losses) gains	(47,161)	39,016	(36,702)
Related tax benefit (expense)	19,282	(15,911)	14,730
Reclassification adjustment for losses (gains) included in net income	5,189	(12,195)	(1,201)
Related tax (benefit) expense	(2,098)	4,963	481
Amortization of unrealized gains on securities transferred from available-for-sale to held-to-maturity	(6,475)	(7,786)	(10,412)
Related tax benefit	2,593	3,134	4,191
Other comprehensive (loss) income, net of tax	(24,902)	8,026	(27,300)
Comprehensive income	494,276	398,292	347,520
Comprehensive income attributable to noncontrolling interests	(28,672)	(7,581)	(30,916)
Comprehensive income attributable to SVBFG	$ 465,604	$ 390,711	$ 316,604