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Employee Benefit Plans - Assumptions Used to Determine Projected and Accumulated Benefit Obligations of Domestic Defined Benefit Pension and Postretirement Benefit Plans (Detail) | Dec. 31, 2020 | Dec. 31, 2019
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Pre-65 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Health care cost trend rate | 7.00% | 7.00%
Ultimate cost trend rate | 4.50% | 4.50%
Post-65 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Health care cost trend rate | 6.80% | 6.80%
Ultimate cost trend rate | 4.50% | 4.50%
Defined benefit pension plans |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Discount rate | 2.20% | 3.00%
Cash balance interest crediting rate | 4.00% | 4.00%
Postretirement benefit plans |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Discount rate | 2.20% | 3.00%
Annual increase in Medicare Part B premium | 6.00% | 6.00%

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- Definition Annual Increase In Medicare Part B Premium Used To Determine Projected And Accumulated Benefit Obligations For Domestic Postretirement Benefit Plans + References No definition available. + Details
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- Definition The ultimate trend rate for health care costs used to determine projected and accumulated benefit obligation. + 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 benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -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 Weighted-average interest crediting rate used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(4) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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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. + References No definition available. + Details
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- Definition Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -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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