Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total	Cumulative adjustment for adoption of amendment	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative adjustment for adoption of amendment	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative adjustment for adoption of amendment	Total SVBFG Stockholders’ Equity	Total SVBFG Stockholders’ Equity Cumulative adjustment for adoption of amendment	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2017					52,835,188
Balance, beginning of period, net of tax at Dec. 31, 2017		$ 4,319,415		$ 0	$ 53	$ 1,314,377	$ 2,866,837		$ (1,472)		$ 4,179,795		$ 139,620
Balance, beginning of period, net of tax (Accounting Standards Update 2014-09) at Dec. 31, 2017			$ (5,802)					$ (5,802)				$ (5,802)
Balance, beginning of period, net of tax (Accounting Standards Update 2016-01) at Dec. 31, 2017			74,595					103,766		$ (29,171)		74,595
Balance, beginning of period, net of tax (Accounting Standards Update 2018-02) at Dec. 31, 2017			0					319		$ (319)		0
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)					456,845
Common stock issued under employee benefit plans, net of restricted stock cancellations		15,810			$ 1	15,809					15,810
Common stock issued under ESOP (in shares)					9,672
Common stock issued under ESOP		2,577				2,577					2,577
Net income		1,011,348					973,840				973,840		37,508
Capital calls and distributions, net		(28,494)											(28,494)
Net change in unrealized gains and losses on AFS securities, net of tax		(15,498)							(15,498)		(15,498)
Amortization of unrealized gains on securities transferred from AFS to HTM, net of tax		(3,330)							(3,330)		(3,330)
Foreign currency translation adjustments, net of tax		(4,330)							(4,330)		(4,330)
Share-based compensation, net		45,675				45,675					45,675
Common stock repurchases (in shares)					(715,207)
Common stock repurchases		(147,123)			$ (1)		(147,122)				(147,123)
Balance (in shares) at Dec. 31, 2018					52,586,498
Balance, end of period, net of tax at Dec. 31, 2018		5,264,843		0	$ 53	1,378,438	3,791,838		(54,120)		5,116,209		148,634
Balance, end of period, net of tax (Accounting Standards Update 2017-08) at Dec. 31, 2018	[1]		(583)					(583)				(583)
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)					586,877
Common stock issued under employee benefit plans, net of restricted stock cancellations		21,312			$ 0	21,312					21,312
Common stock issued under ESOP (in shares)					14,442
Common stock issued under ESOP		3,506				3,506					3,506
Net income		1,184,717					1,136,856				1,136,856		47,861
Capital calls and distributions, net		(50,978)											(50,978)
Net change in unrealized gains and losses on AFS securities, net of tax		139,934							139,934		139,934
Amortization of unrealized gains on securities transferred from AFS to HTM, net of tax		(1,558)							(1,558)		(1,558)
Foreign currency translation adjustments, net of tax		2,319							2,319		2,319
Net change in unrealized gains and losses on cash flow hedges, net of tax		(2,130)							(2,130)		(2,130)
Share-based compensation, net		66,815				66,815					66,815
Common stock repurchases (in shares)					(1,532,210)
Common stock repurchases		(352,511)			$ (1)		(352,510)				(352,511)
Acquisition of SVB Leerink		5,256											5,256
Issuance of Series A Preferred Stock		340,138		340,138							340,138
Balance (in shares) at Dec. 31, 2019					51,655,607
Balance, end of period, net of tax at Dec. 31, 2019		6,621,080		340,138	$ 52	1,470,071	4,575,601		84,445		6,470,307		150,773
Balance, end of period, net of tax (ASC 326) at Dec. 31, 2019	[1]		$ (35,049)					$ (35,049)				$ (35,049)
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)					464,985
Common stock issued under employee benefit plans, net of restricted stock cancellations		28,699			$ 0	28,699					28,699
Common stock issued under ESOP (in shares)					12,094
Common stock issued under ESOP		2,447				2,447					2,447
Net income		1,294,294					1,208,368				1,208,368		85,926
Capital calls and distributions, net		(22,908)											(22,908)
Net change in unrealized gains and losses on AFS securities, net of tax		393,305							393,305		393,305
Amortization of unrealized gains on securities transferred from AFS to HTM, net of tax		1,518							1,518		1,518
Foreign currency translation adjustments, net of tax		11,846							11,846		11,846
Net change in unrealized gains and losses on cash flow hedges, net of tax		131,403							131,403		131,403
Share-based compensation, net		$ 83,986				83,986					83,986
Common stock repurchases (in shares)		(244,223)			(244,223)
Common stock repurchases		$ (60,020)			$ 0		(60,020)				(60,020)
Dividends on preferred stock		(17,151)									(17,151)
Other, net		41				41					41
Balance (in shares) at Dec. 31, 2020					51,888,463
Balance, end of period, net of tax at Dec. 31, 2020		$ 8,433,491		$ 340,138	$ 52	$ 1,585,244	$ 5,671,749		$ 622,517		$ 8,219,700		$ 213,791

[1] See Note 2- "Summary of Significant Accounting Policies" for additional details.