Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three months ended March 31, 2021, income tax benefit was $896. Income tax expense for the three months ended March 31, 2020, was $438. The effective consolidated income tax rates were (52)% and 15% for the three months ended March 31, 2021, and 2020, respectively. The lower effective rates for the three months ended March 31, 2021, were primarily due to excess tax benefits relating to share-based payment awards, state tax credits and other discrete tax items. SJW Group had unrecognized tax benefits, before the impact of deductions of state taxes, excluding interest and penalties of approximately $6,511 and $6,468 as of March 31, 2021 and December 31, 2020, respectively. SJW Group does not expect its unrecognized tax benefits to change significantly within the next 12 months. On March 11, 2021, the American Rescue Plan Act was signed into law. SJW Group is currently evaluating the impact this legislation may have on the consolidated financial results.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.