| Standard label: | Water [Member] |
| Name: | us-gaap:PublicUtilitiesInventoryWaterMember |
| Documentation: | Clear, colorless, odorless and tasteless liquid essential for most plant and animal life comprised of two parts hydrogen and one part oxygen (H2O). |
| Object type: | cm:Member |
| Data type: | [Member] (nonnum:domainItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:PublicUtilitiesInventoryWaterMember |
| Label | Role | Language |
| Water [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 210 10 S99 1 (SX 210.5-02(6)(a)(4)) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |