Employee Compensation and Benefit Plans - Expenses Incurred Under Certain Employee Compensation and Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Incentive Compensation Plan	$ 160,293	$ 125,584	$ 96,892
Direct Drive Incentive Compensation Plan	40,578	18,721	21,174
Retention Program	1,438	1,317	1,475
Warrant Incentive Plan	9,112	15,386	4,954
Deferred Compensation Plan	0	203	1,318
SVBFG 401(k) Plan	21,323	17,860	16,078
SVBFG ESOP	$ 6,435	$ 4,719	$ 3,159

Expense for annual sales incentive program.

No definition available.

Name:	sivb_DirectDriveIncentiveCompensationPlanExpense
Namespace Prefix:	sivb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expense for annual cash incentive plan that rewards performance based on the entity's financial results and other performance criteria.

+ References

No definition available.

+ Details

Name:	sivb_IncentiveCompensationExpenses
Namespace Prefix:	sivb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expense for long-term incentive plans that allows designated employees to share directly in the entity's investment success.

+ References

No definition available.

+ Details

Name:	sivb_RetentionProgramExpense
Namespace Prefix:	sivb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expense for warrant incentive plan which provides individual and team awards to those employees who negotiate warrants on the entity's behalf.

+ References

No definition available.

+ Details

Name:	sivb_WarrantIncentivePlanExpense
Namespace Prefix:	sivb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of plan compensation cost recognized during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109244661&loc=d3e17540-113929

+ Details

Name:	us-gaap_EmployeeStockOwnershipPlanESOPCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration