Deposits - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Time deposits equal to or greater than $250,000	$ 42	$ 37
Time deposits equal to or greater than $250,000 maturing within one year	$ 42

Contractual Maturities, Time Deposits, $250,000 Or More, After 12 Months

No definition available.

Name:	sivb_ContractualMaturitiesTimeDeposits250000OrMoreAfter12Months
Namespace Prefix:	sivb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant