Interim Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interests	$ 154,118	$ 115,647	$ 394,514	$ 286,624
Change in cumulative translation gains (losses):
Foreign currency translation gains (losses)	1,928	(119)	4,463	(2,168)
Related tax (expense) benefit	(787)	50	(1,821)	885
Change in unrealized gains (losses) on available-for-sale securities:
Unrealized holding gains (losses)	925	(54,204)	(12,471)	157,564
Related tax (expense) benefit	(429)	21,932	5,207	(64,357)
Reclassification adjustment for losses (gains) included in net income	101	15	(384)	(11,567)
Related tax (benefit) expense	(41)	(6)	157	4,707
Amortization of unrealized gains on securities transferred from available-for-sale to held-to-maturity	(1,594)	(1,690)	(4,931)	(6,507)
Related tax benefit	641	680	1,984	2,618
Other comprehensive income (loss), net of tax	744	(33,342)	(7,796)	81,175
Comprehensive income	154,862	82,305	386,718	367,799
Comprehensive income attributable to noncontrolling interests	(5,498)	(4,566)	(21,218)	(3,405)
Comprehensive income attributable to SVBFG	$ 149,364	$ 77,739	$ 365,500	$ 364,394