Interim Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interests	$ 281,718	$ 281,365	$ 909,901	$ 736,417
Change in foreign currency cumulative translation gains and losses:
Foreign currency translation losses	(6,213)	(3,259)	(6,307)	(5,337)
Related tax benefit	1,731	905	1,757	1,482
Change in unrealized gains and losses on available-for-sale securities:
Unrealized holding gains (losses)	70,185	(24,902)	236,203	(98,032)
Related tax (expense) benefit	(19,547)	6,994	(65,786)	27,269
Reclassification adjustment for losses included in net income	0	0	3,905	0
Related tax benefit	0	0	(1,087)	0
Reclassification of unrealized gains on equity securities to retained earnings for ASU 2016-01	0	0	0	(40,316)
Related tax expense	0	0	0	11,145
Amortization of unrealized holding gains on securities transferred from available-for-sale to held-to-maturity	(374)	(1,777)	(1,767)	(3,915)
Related tax benefit	104	494	492	1,085
Reclassification of stranded tax effect to retained earnings for ASU 2018-02	0	0	0	(319)
Change in unrealized gains and losses on cash flow hedges:
Unrealized gains	9,810	0	28,466	0
Related tax expense	(2,733)	0	(7,930)	0
Reclassification adjustment for losses included in net income	2,713	0	3,224	0
Related tax benefit	(755)	0	(897)	0
Other comprehensive income (loss), net of tax	54,921	(21,545)	190,273	(106,938)
Comprehensive income	336,639	259,820	1,100,174	629,479
Comprehensive income attributable to noncontrolling interests	(14,437)	(6,548)	(35,901)	(28,841)
Comprehensive income attributable to SVBFG	$ 322,202	$ 253,272	$ 1,064,273	$ 600,638