XML 40 R30.htm IDEA: XBRL DOCUMENT
v3.20.2

Narrative (Details) | 6 Months Ended
--- | ---
Jun. 30, 2020
Accounting Policies [Abstract] |
Maximum collection period | 24 months

X
- Definition Represents the maximum collection period in which deferred net WRAM and MCBA revenues and associated costs will be recognized. + References No definition available. + Details
Name: | cwt_MaximumCollectionPeriodInWhichDeferredNetWRAMAndMCBARevenuesAndAssociatedCostsWillBeRecognized
Namespace Prefix: | cwt_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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