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Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Employee Benefit Plan [Abstract] |  |  |
Profit Sharing and Retirement Savings Plan, plan expense | $ 86.6 | $ 181.4 | $ 307.9
Unfunded obligation | 28.2 | 27.0 |
Expense associated with early retiree medical plan | $ 2.5 | $ 2.0 | $ 2.1
Discount rate used to calculate benefit obligation | 2.40% | 3.23% | 4.24%
Health care cost trend rate | 5.70% | 6.00% | 6.30%
Projected ultimate future health care cost trend rate | 4.50% |  |
Year that trend rate is projected to reach ultimate rate | 2037 |  |

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- Definition The health care cost trend rate used. + References No definition available. + Details
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- Definition Early retiree medical plan benefit (expense). + References No definition available. + Details
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- Definition Employee Benefit Plan [Abstract] + References No definition available. + Details
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- Definition Costs and payments related to employee profit sharing and retirement savings plans. + References No definition available. + Details
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Ultimate trend rate for health care cost for defined benefit postretirement plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Year ultimate health care cost trend rate is expected to be reached, in CCYY format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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