Related Party Transactions (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions [Abstract]
Deposit From Related Party	$ 7,574	$ 5,069

The carrying amount of deposit due from related party associated with the reporting entity's as on the balance sheet date.

No definition available.

Name:	bsrr_DepositFromRelatedParty
Namespace Prefix:	bsrr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant