| Pay vs Performance Disclosure | 12 Months Ended |
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) |
| Pay vs Performance Disclosure [Table] | | | |
| Pay vs Performance [Table Text Block] | Value of $100 Average Investment SCT Average Comp. Based on: Net Total Comp. SCT Total Actually S&P 500 Income Comp. Actually Comp. for Paid to Multi- (GAAP) Adjusted for Paid to Other Other Company Utilities (Millions) Operating Year CEO ($) CEO ($)(1) NEOs ($) NEOs ($)(1) TSR ($) TSR ($) ($) EPS ($) 2022 10,458,218 13,114,345 2,758,157 3,470,373 117.42 108.12 1,083 6.10 2021 11,128,277 18,169,622 3,463,650 4,816,926 116.00 107.50 907 5.99 2020 10,605,622 12,523,751 4,387,339 4,768,267 97.10 94.10 1,368 5.61 (1) The tables below show the amounts deducted and added to the total compensation listed in the summary compensation table to arrive at the compensation actually paid to the CEO and the other NEOs. Chief Executive Officer 2022 2021* 2020 Deduction for change in actuarial present value of accumulated benefit under defined benefit and actuarial pension plans (37,810) (1,073,599) (892,005) Addition for aggregate of FY service cost under defined benefit and actuarial service plans 381,539 331,385 269,273 Deduction of amounts reported under "Stock Awards" in Summary Compensation Table (7,013,377) (6,524,979) (5,614,868) Addition of fair value at FY end of all awards granted during FY that are outstanding and unvested at FY end** 7,609,697 11,738,385 6,341,699 Addition of change in fair value at FY end (from the end of the prior FY) of any awards granted in a prior FY that are outstanding and unvested at FY end** 1,424,801 2,421,441 1,601,297 Addition of change in fair value at vesting date of awards granted in any prior FY for which vesting conditions were satisfied during covered FY** 101,128 (10,682) 84,625 Addition of dollar value of any dividends or other earnings paid on stock awards in the covered FY prior to vesting date 190,149 159,392 128,108 Other NEOs (average) 2022 2021* 2020 Deduction for change in actuarial present value of accumulated benefit under defined benefit and actuarial pension plans (81,237) (686,317) (1,410,659) Addition for aggregate of FY service cost under defined benefit and actuarial service plans 177,644 242,483 339,090 Deduction of amounts reported under "Stock Awards" in Summary Compensation Table (1,451,777) (1,373,076) (1,506,869) Addition of fair value at FY end of all awards granted during FY that are outstanding and unvested at FY end** 1,632,365 2,495,901 1,606,841 Addition of change in fair value at FY end (from the end of the prior FY) of any awards granted in a prior FY that are outstanding and unvested at FY end** 386,428 640,575 1,158,989 Addition of change in fair value at vesting date of awards granted in any prior FY for which vesting conditions were satisfied during covered FY** 17,126 (3,773) 113,301 Addition of dollar value of any dividends or other earnings paid on stock awards in the covered FY prior to vesting date 31,666 37,484 80,235 | | |
| Company Selected Measure Name | Adjusted Operating EPS | | |
| Named Executive Officers, Footnote [Text Block] | For each covered fiscal year, these are the names of the CEO and each non-CEO NEO whose compensation is included in the Pay versus Performance table below: Year CEO Non-CEO NEOs 2022 Gerardo Norcia David Ruud, JoAnn Chavez, Trevor F. Lauer, Mark W. Stiers 2021 Gerardo Norcia David Ruud, Trevor F. Lauer, David E. Meador, Mark W. Stiers 2020 Gerardo Norcia David Ruud, Peter B. Oleksiak, Gerard M. Anderson, Trevor F. Lauer, David E. Meador | | |
| PEO Total Compensation Amount | $ 10,458,218 | $ 11,128,277 | $ 10,605,622 |
| PEO Actually Paid Compensation Amount | $ 13,114,345 | 18,169,622 | 12,523,751 |
| Adjustment To PEO Compensation, Footnote [Text Block] | (1) The tables below show the amounts deducted and added to the total compensation listed in the summary compensation table to arrive at the compensation actually paid to the CEO and the other NEOs. Chief Executive Officer 2022 2021* 2020 Deduction for change in actuarial present value of accumulated benefit under defined benefit and actuarial pension plans (37,810) (1,073,599) (892,005) Addition for aggregate of FY service cost under defined benefit and actuarial service plans 381,539 331,385 269,273 Deduction of amounts reported under "Stock Awards" in Summary Compensation Table (7,013,377) (6,524,979) (5,614,868) Addition of fair value at FY end of all awards granted during FY that are outstanding and unvested at FY end** 7,609,697 11,738,385 6,341,699 Addition of change in fair value at FY end (from the end of the prior FY) of any awards granted in a prior FY that are outstanding and unvested at FY end** 1,424,801 2,421,441 1,601,297 Addition of change in fair value at vesting date of awards granted in any prior FY for which vesting conditions were satisfied during covered FY** 101,128 (10,682) 84,625 Addition of dollar value of any dividends or other earnings paid on stock awards in the covered FY prior to vesting date 190,149 159,392 128,108 | | |
| Non-PEO NEO Average Total Compensation Amount | $ 2,758,157 | 3,463,650 | 4,387,339 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 3,470,373 | 4,816,926 | 4,768,267 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | (1) The tables below show the amounts deducted and added to the total compensation listed in the summary compensation table to arrive at the compensation actually paid to the CEO and the other NEOs. Other NEOs (average) 2022 2021* 2020 Deduction for change in actuarial present value of accumulated benefit under defined benefit and actuarial pension plans (81,237) (686,317) (1,410,659) Addition for aggregate of FY service cost under defined benefit and actuarial service plans 177,644 242,483 339,090 Deduction of amounts reported under "Stock Awards" in Summary Compensation Table (1,451,777) (1,373,076) (1,506,869) Addition of fair value at FY end of all awards granted during FY that are outstanding and unvested at FY end** 1,632,365 2,495,901 1,606,841 Addition of change in fair value at FY end (from the end of the prior FY) of any awards granted in a prior FY that are outstanding and unvested at FY end** 386,428 640,575 1,158,989 Addition of change in fair value at vesting date of awards granted in any prior FY for which vesting conditions were satisfied during covered FY** 17,126 (3,773) 113,301 Addition of dollar value of any dividends or other earnings paid on stock awards in the covered FY prior to vesting date 31,666 37,484 80,235 | | |
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | - | | |
| Compensation Actually Paid vs. Net Income [Text Block] | | | |
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | | | |
| Tabular List [Table Text Block] | Listed below are the most important financial performance measures we used in 2022 to link executive compensation to company performance: ■ Adjusted Operating Earnings Per Share ■ Relative Total Shareholder Return vs Peer Group (percentile) ■ Cash from Operations | | |
| Total Shareholder Return Amount | $ 117.42 | 116 | 97.10 |
| Peer Group Total Shareholder Return Amount | 108.12 | 107.50 | 94.10 |
| Net Income (Loss) | $ 1,083,000,000 | $ 907,000,000 | $ 1,368,000,000 |
| Company Selected Measure Amount | 6.10 | 5.99 | 5.61 |
| PEO Name | Gerardo Norcia | | |
| Measure [Axis]: 1 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Adjusted Operating Earnings Per Share | | |
| Measure [Axis]: 2 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Relative Total Shareholder Return vs Peer Group (percentile) | | |
| Measure [Axis]: 3 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Cash from Operations | | |
| PEO [Member] | Deduction for change in actuarial present value of accumulated benetit under defined benefit and actuarial pension plans | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ (37,810) | $ (1,073,599) | $ (892,005) |
| PEO [Member] | Addition for aggregate of FY service cost under defined benefit and actuarial service plans | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 381,539 | 331,385 | 269,273 |
| PEO [Member] | Deduction of amounts reported under "Stock Awards" in Summary Compensation Table | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | (7,013,377) | (6,524,979) | (5,614,868) |
| PEO [Member] | Addition of fair value at FY end of all awards granted during FY that are outstanding and unvested at FY end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 7,609,697 | 11,738,385 | 6,341,699 |
| PEO [Member] | Addition of change in fair value at FY end (from the end of the prior FY) of any award granted in a prior FY that are outstanding and unvested at FY end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 1,424,801 | 2,421,441 | 1,601,297 |
| PEO [Member] | Addition of change in fair value at vesting date of awards granted in any prior FY for which vesting conditions were satisfied during covered FY | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 101,128 | (10,682) | 84,625 |
| PEO [Member] | Addition of dollar value of any dividends or other earnings paid on stock awards in the covered FY prior to vesting date | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 190,149 | 159,392 | 128,108 |
| Non-PEO NEO [Member] | Deduction for change in actuarial present value of accumulated benetit under defined benefit and actuarial pension plans | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | (81,237) | (686,317) | (1,410,659) |
| Non-PEO NEO [Member] | Addition for aggregate of FY service cost under defined benefit and actuarial service plans | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 177,644 | 242,483 | 339,090 |
| Non-PEO NEO [Member] | Deduction of amounts reported under "Stock Awards" in Summary Compensation Table | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | (1,451,777) | (1,373,076) | (1,506,869) |
| Non-PEO NEO [Member] | Addition of fair value at FY end of all awards granted during FY that are outstanding and unvested at FY end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 1,632,365 | 2,495,901 | 1,606,841 |
| Non-PEO NEO [Member] | Addition of change in fair value at FY end (from the end of the prior FY) of any award granted in a prior FY that are outstanding and unvested at FY end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 386,428 | 640,575 | 1,158,989 |
| Non-PEO NEO [Member] | Addition of change in fair value at vesting date of awards granted in any prior FY for which vesting conditions were satisfied during covered FY | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 17,126 | (3,773) | 113,301 |
| Non-PEO NEO [Member] | Addition of dollar value of any dividends or other earnings paid on stock awards in the covered FY prior to vesting date | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ 31,666 | $ 37,484 | $ 80,235 |
