The Business of Sierra Bancorp - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Jan. 31, 1978
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Capital			$ 1,500
Assets	$ 3,418,854	$ 3,371,014
Cash, FDIC Insured Amount	$ 2,900,000