XML 64 R48.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Regulatory Matters - Balancing and Memorandum Accounts (Details) $ in Thousands | Dec. 31, 2021 USD ($)
--- | ---
Regulated Operations [Abstract] |
Authorized revenue, threshold percentage | 2.00%
Net under-collected accounts | $ 2,312

X
- Definition Regulatory Balancing and Memorandum Accounts,, Net Under-Collected + References No definition available. + Details
Name: | sjw_RegulatoryBalancingandMemorandumAccountsNetUnderCollected
Namespace Prefix: | sjw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Threshold balance of regulatory balancing or memorandum accounts as a percentage of authorized revenue to trigger an account review. + References No definition available. + Details
Name: | sjw_RegulatoryBalancingandMemorandumAccountsReviewAuthorizedRevenueThresholdPercentage
Namespace Prefix: | sjw_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_RegulatedOperationsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration