Employee Benefits - Amounts Recognized in Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
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| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Pension settlement charge | $ (98.7) | $ (65.9) | |
| Net gain | $ (38.6) | (142.4) | (41.8) |
| Pension Benefits [Member] | |||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Net actuarial gain | (15.4) | (28.7) | |
| Amortization of net actuarial loss (gain) | (8.0) | (14.0) | |
| Pension settlement charge | (98.7) | $ 65.9 | |
| Net gain | (23.4) | (141.4) | |
| Other Postretirement Benefits [Member] | |||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Net actuarial gain | (18.4) | (7.0) | |
| Amortization of net actuarial loss (gain) | 5.8 | 6.0 | |
| Amortization of prior service cost | 0.1 | 0.5 | |
| Net gain | $ (12.5) | $ (0.5) | |
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- Definition Defined benefit plan pension settlement expense or accrual. No definition available.
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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, before tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, before tax, after reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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