Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesSJW Group is subject to ordinary routine litigation incidental to its business. There are no pending legal proceedings to which SJW Group or any of its subsidiaries is a party, or to which any of its properties is the subject, that are expected to have a material effect on SJW Group’s business, financial position, results of operations or cash flows.