REGULATORY MATTERS - REGULATORY BALANCING ACCOUNTS (Details) - USD ($) $ in Millions |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Regulatory Balancing Accounts [Line Items] | ||
| Overcollected | $ (804) | $ (789) |
| Undercollected | 941 | 1,062 |
| Net current receivable (payable) | 137 | 273 |
| Undercollected | 85 | 215 |
| Net noncurrent receivable (payable) | 85 | 215 |
| Total net receviable (payable) | 222 | 488 |
| San Diego Gas and Electric Company [Member] | ||
| Regulatory Balancing Accounts [Line Items] | ||
| Overcollected | (301) | (345) |
| Undercollected | 560 | 652 |
| Net current receivable (payable) | 259 | 307 |
| Undercollected | 0 | 0 |
| Net noncurrent receivable (payable) | 0 | 0 |
| Total net receviable (payable) | 259 | 307 |
| Southern California Gas Company [Member] | ||
| Regulatory Balancing Accounts [Line Items] | ||
| Overcollected | (503) | (444) |
| Undercollected | 381 | 410 |
| Net current receivable (payable) | (122) | (34) |
| Undercollected | 85 | 215 |
| Net noncurrent receivable (payable) | 85 | 215 |
| Total net receviable (payable) | $ (37) | $ 181 |