Retirement Benefits (Components of Net Periodic (Benefit) Cost) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2023 |
Jun. 30, 2022 |
Jun. 30, 2023 |
Jun. 30, 2022 |
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| Defined Benefit Pension Plans | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 74.9 | $ 88.2 | $ 145.3 | $ 177.3 |
| Interest cost | 162.6 | 99.6 | 323.7 | 200.1 |
| Expected return on plan assets | (264.2) | (237.0) | (527.5) | (476.5) |
| Amortization of prior service cost | 0.6 | 0.6 | 1.2 | 1.3 |
| Recognized actuarial (gain) loss | 30.9 | 84.5 | 60.9 | 171.5 |
| Net periodic cost | 4.8 | 35.9 | 3.6 | 73.7 |
| Retiree Health Benefit Plans | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | 8.2 | 12.1 | 15.9 | 23.3 |
| Interest cost | 15.3 | 9.6 | 30.7 | 19.0 |
| Expected return on plan assets | (45.6) | (38.2) | (91.1) | (76.1) |
| Amortization of prior service cost | (13.2) | (13.7) | (26.4) | (27.4) |
| Recognized actuarial (gain) loss | (2.0) | 0.3 | (2.9) | 0.5 |
| Net periodic cost | $ (37.3) | $ (29.9) | $ (73.8) | $ (60.7) |
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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