OTHER FINANCIAL DATA - INCOME TAXES (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items] | ||||
| Income tax expense | $ 282 | $ 15 | $ 284 | $ 276 |
| Effective income tax rate | 29.00% | 6.00% | 21.00% | 22.00% |
| San Diego Gas and Electric Company [Member] | ||||
| Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items] | ||||
| Income tax expense | $ 91 | $ 75 | $ 204 | $ 217 |
| Effective income tax rate | 32.00% | 29.00% | 33.00% | 32.00% |
| Southern California Gas Company [Member] | ||||
| Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items] | ||||
| Income tax expense | $ 21 | $ (20) | $ 75 | $ 91 |
| Effective income tax rate | 100.00% | 71.00% | 27.00% | 25.00% |