Document and Entity Information
| Document and Entity Information | Jun. 02, 2020 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | CENTERPOINT ENERGY HOUSTON ELECTRIC LLC |
| Amendment Flag | false |
| Entity Central Index Key | 0000048732 |
| Document Type | 8-K |
| Document Period End Date | Jun. 2, 2020 |
| Entity Incorporation, State or Country Code | TX |
| Entity File Number | 1-3187 |
| Entity Tax Identification Number | 22-3865106 |
| Entity Address, Address Line One | 1111 Louisiana |
| Entity Address, City or Town | Houston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77002 |
| City Area Code | 713 |
| Local Phone Number | 207-1111 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| 9.15% First Mortgage Bonds due 2021 | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | 9.15% First Mortgage Bonds due 2021 |
| No Trading Symbol Flag | true |
| Security Exchange Name | NYSE |
| 6.95% General Mortgage Bonds due 2033 | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | 6.95% General Mortgage Bonds due 2033 |
| No Trading Symbol Flag | true |
| Security Exchange Name | NYSE |