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Retirement Plans - Benefits Plans (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jul. 01, 2018 | Jul. 02, 2017 | Jul. 01, 2018 | Jul. 02, 2017
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Required employer contributions to defined-benefit retirement plans during the fiscal year | $ 315 |  | $ 315 |
Expected future employer contributions to defined-benefit retirement plans during the fiscal year | 570 |  | 570 |
Pension Plans, Defined Benefit |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Service cost | 44 | $ 42 | 90 | $ 84
Interest cost | 140 | 113 | 254 | 226
Expected return on plan assets | (228) | (170) | (407) | (339)
Recognized net actuarial loss (gain) | 93 | 86 | 189 | 172
Amortization of prior service credit | (11) | (16) | (22) | (33)
Net periodic benefit cost (credit) | 38 | 55 | 104 | 110
Other Postretirement Benefit Plans, Defined Benefit |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Service cost | 2 | 3 | 5 | 6
Interest cost | 8 | 9 | 16 | 17
Expected return on plan assets | (10) | (9) | (19) | (17)
Recognized net actuarial loss (gain) | (1) | (1) | (2) | (2)
Amortization of prior service credit | (1) | (1) | (2) | (2)
Net periodic benefit cost (credit) | $ (2) | $ 1 | $ (2) | $ 2

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- Definition Defined Benefit Plan, Expected Future Discretionary Employer Contributions, Current Fiscal Year + References No definition available. + Details
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- Definition Defined Benefit Plan, Expected Future Required Employer Contributions, Current Fiscal Year + References No definition available. + Details
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(4) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(5) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(3) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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