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v3.23.1

Retirement Benefits (Schedule Of Net Benefit Costs) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
DB Pension Plans |  |
Defined Benefit Plan, Roll Forwards [Abstract] |  |
Service cost | $ 7 | $ 12
Interest cost | 27 | 18
Expected return on plan assets | (55) | (52)
Amortization of |  |
Net loss | 3 | 17
Prior service cost (credit) | 1 | 1
Settlement loss | 2 | 2
Net periodic credit | (15) | (2)
DB Pension Plans | Volatility Mechanism |  |
Amortization of |  |
Deferred costs (credits) | 3 |
DB Pension Plans | Consumers Energy Company |  |
Defined Benefit Plan, Roll Forwards [Abstract] |  |
Service cost | 7 | 12
Interest cost | 25 | 16
Expected return on plan assets | (52) | (49)
Amortization of |  |
Net loss | 3 | 16
Prior service cost (credit) | 1 | 1
Settlement loss | 2 | 2
Net periodic credit | (14) | (2)
OPEB Plan |  |
Defined Benefit Plan, Roll Forwards [Abstract] |  |
Service cost | 3 | 4
Interest cost | 11 | 7
Expected return on plan assets | (26) | (29)
Amortization of |  |
Net loss | 3 | 0
Prior service cost (credit) | (10) | (12)
Settlement loss | 0 | 0
Net periodic credit | (19) | (30)
OPEB Plan | Volatility Mechanism |  |
Amortization of |  |
Deferred costs (credits) | (6) |
OPEB Plan | Consumers Energy Company |  |
Defined Benefit Plan, Roll Forwards [Abstract] |  |
Service cost | 3 | 4
Interest cost | 11 | 7
Expected return on plan assets | (24) | (27)
Amortization of |  |
Net loss | 3 | 0
Prior service cost (credit) | (10) | (12)
Settlement loss | 0 | 0
Net periodic credit | $ (17) | $ (28)

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