Interim Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock	Additional Paid-in Capital	Retained Earnings		Accumulated Other Comprehensive Income (Loss)		Total SVBFG Stockholders’ Equity	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2016			52,254,074
Balance at Dec. 31, 2016		$ 3,777,037	$ 52	$ 1,242,741	$ 2,376,331		$ 23,430		$ 3,642,554	$ 134,483
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)			458,742
Common stock issued under employee benefit plans, net of restricted stock cancellations		14,192	$ 1	14,191					14,192
Common stock issued under ESOP (in shares)			10,838
Common stock issued under ESOP		2,094		2,094					2,094
Net income		394,514			373,296				373,296	21,218
Capital calls and distributions, net		(18,216)								(18,216)
Net change in unrealized gains and losses on AFS securities, net of tax		(7,491)					(7,491)		(7,491)
Amortization of unrealized holding gains on securities transferred from AFS to HTM, net of tax		(2,947)					(2,947)		(2,947)
Foreign currency translation adjustments, net of tax		2,642					2,642		2,642
Share-based compensation, net		35,473		35,473					35,473
Reclassification of stranded tax effect for ASU 2018-02	[1]	0
Balance (in shares) at Sep. 30, 2017			52,723,654
Balance at Sep. 30, 2017		4,197,298	$ 53	1,294,499	2,749,627		15,634		4,059,813	137,485
Balance (in shares) at Jun. 30, 2017			52,684,159
Balance at Jun. 30, 2017		4,040,035	$ 53	1,283,485	2,601,007		14,890		3,899,435	140,600
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)			39,495
Common stock issued under employee benefit plans, net of restricted stock cancellations		2,370	$ 0	2,370					2,370
Net income		154,118			148,620				148,620	5,498
Capital calls and distributions, net		(8,613)								(8,613)
Net change in unrealized gains and losses on AFS securities, net of tax		556					556		556
Amortization of unrealized holding gains on securities transferred from AFS to HTM, net of tax		(953)					(953)		(953)
Foreign currency translation adjustments, net of tax		1,141					1,141		1,141
Share-based compensation, net		8,644		8,644					8,644
Reclassification of stranded tax effect for ASU 2018-02	[1]	0
Balance (in shares) at Sep. 30, 2017			52,723,654
Balance at Sep. 30, 2017		4,197,298	$ 53	1,294,499	2,749,627		15,634		4,059,813	137,485
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative adjustment for ASU, net of tax | Accounting Standards Update 2014-09	[2]	(5,802)			(5,802)				(5,802)
Cumulative adjustment for ASU, net of tax | Accounting Standards Update 2016-01	[2]	74,595			103,766		(29,171)		74,595
Balance (in shares) at Dec. 31, 2017			52,835,188
Balance at Dec. 31, 2017		4,319,415	$ 53	1,314,377	2,866,837		(1,472)		4,179,795	139,620
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)			405,395
Common stock issued under employee benefit plans, net of restricted stock cancellations		9,108	$ 0	9,108					9,108
Common stock issued under ESOP (in shares)			9,672
Common stock issued under ESOP		2,577		2,577					2,577
Net income		736,417			707,576				707,576	28,841
Capital calls and distributions, net		(22,785)								(22,785)
Net change in unrealized gains and losses on AFS securities, net of tax		(70,763)					(70,763)		(70,763)
Amortization of unrealized holding gains on securities transferred from AFS to HTM, net of tax		(2,830)					(2,830)		(2,830)
Foreign currency translation adjustments, net of tax		(3,855)					(3,855)		(3,855)
Share-based compensation, net		33,968		33,968					33,968
Reclassification of stranded tax effect for ASU 2018-02	[1]	319
Reclassification of stranded tax effect for ASU 2018-02 | Accounting Standards Update 2018-02		300			319	[2]	(319)	[2]
Balance (in shares) at Sep. 30, 2018			53,250,255
Balance at Sep. 30, 2018		5,070,045	$ 53	1,360,030	3,672,696		(108,410)		4,924,369	145,676
Balance (in shares) at Jun. 30, 2018			53,210,627
Balance at Jun. 30, 2018		4,804,841	$ 53	1,346,586	3,397,879		(86,865)		4,657,653	147,188
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)			39,628
Common stock issued under employee benefit plans, net of restricted stock cancellations		1,943	$ 0	1,943					1,943
Net income		281,365			274,817				274,817	6,548
Capital calls and distributions, net		(8,060)								(8,060)
Net change in unrealized gains and losses on AFS securities, net of tax		(17,908)					(17,908)		(17,908)
Amortization of unrealized holding gains on securities transferred from AFS to HTM, net of tax		(1,283)					(1,283)		(1,283)
Foreign currency translation adjustments, net of tax		(2,354)					(2,354)		(2,354)
Share-based compensation, net		11,501		11,501					11,501
Reclassification of stranded tax effect for ASU 2018-02	[1]	0
Balance (in shares) at Sep. 30, 2018			53,250,255
Balance at Sep. 30, 2018		$ 5,070,045	$ 53	$ 1,360,030	$ 3,672,696		$ (108,410)		$ 4,924,369	$ 145,676

[1] See "Adoption of New Accounting Standards" in Note 1—“Basis of Presentation” of the “Notes to Interim Consolidated Financial Statements (unaudited)” under Part I, Item 1 of this report for additional details.

[2] See "Adoption of New Accounting Standards" in Note 1—“Basis of Presentation” of the “Notes to Interim Consolidated Financial Statements (unaudited)” under Part I, Item 1 of this report for additional details.