Income Taxes	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesFor the three and six months ended June 30, 2022, income tax expense was $2,368 and $3,435, respectively. Income tax expense for the three and six months ended June 30, 2021, was $3,306 and $2,410, respectively. The effective consolidated income tax rates were 17% and 14% for the three months ended June 30, 2022 and 2021, respectively, and 18% and 9% for the six months ended June 30, 2022, and 2021, respectively. The higher effective tax rate for the three and six months ended June 30, 2022, was primarily due to discrete tax expense items.SJW Group had unrecognized tax benefits, before the impact of deductions of state taxes, excluding interest and penalties, of approximately $8,221 and $7,961 as of June 30, 2022, and December 31, 2021, respectively. SJW Group does not expect its unrecognized tax benefits to change significantly within the next 12 months.