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Pension and Other Postretirement Benefit Plans (Tables) | 12 Months Ended
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Dec. 31, 2017
Retirement Benefits [Abstract] |
Components of Net Periodic Benefit Cost | The net periodic benefit cost (credit) for pension and other postretirement benefit plans consisted of the following components:
| Pension Benefits |  |  |  |  |  |
| U.S. |  | International |  | Other Postretirement Benefits
Years Ended December 31 | 2017 |  | 2016 |  | 2015 |  | 2017 |  | 2016 |  | 2015 |  | 2017 |  | 2016 |  | 2015
Service cost | $ | 312 |  |  | $ | 282 |  |  | $ | 307 |  |  | $ | 252 |  |  | $ | 238 |  |  | $ | 251 |  |  | $ | 57 |  |  | $ | 54 |  |  | $ | 80 |
Interest cost | 454 |  |  | 456 |  |  | 434 |  |  | 172 |  |  | 204 |  |  | 206 |  |  | 81 |  |  | 82 |  |  | 110 |
Expected return on plan assets | (862 | ) |  | (831 | ) |  | (819 | ) |  | (393 | ) |  | (382 | ) |  | (379 | ) |  | (78 | ) |  | (107 | ) |  | (143 | )
Amortization of unrecognized prior service cost | (53 | ) |  | (55 | ) |  | (56 | ) |  | (11 | ) |  | (11 | ) |  | (14 | ) |  | (98 | ) |  | (106 | ) |  | (64 | )
Net loss amortization | 180 |  |  | 119 |  |  | 214 |  |  | 98 |  |  | 87 |  |  | 118 |  |  | 1 |  |  | 3 |  |  | 5 |
Termination benefits | 44 |  |  | 23 |  |  | 22 |  |  | 4 |  |  | 4 |  |  | 1 |  |  | 8 |  |  | 4 |  |  | 7 |
Curtailments | 3 |  |  | 5 |  |  | (12 | ) |  | (4 | ) |  | (1 | ) |  | (9 | ) |  | (31 | ) |  | (18 | ) |  | (19 | )
Settlements | — |  |  | — |  |  | 1 |  |  | 5 |  |  | 6 |  |  | 12 |  |  | — |  |  | — |  |  | — |
Net periodic benefit cost (credit) | $ | 78 |  |  | $ | (1 | ) |  | $ | 91 |  |  | $ | 123 |  |  | $ | 145 |  |  | $ | 186 |  |  | $ | (60 | ) |  | $ | (88 | ) |  | $ | (24 | )
Obligation and Funded Status | Summarized information about the changes in plan assets and benefit obligations, the funded status and the amounts recorded at December 31 is as follows:
| Pension Benefits |  | Other Postretirement Benefits
| U.S. |  | International |
| 2017 |  | 2016 |  | 2017 |  | 2016 |  | 2017 |  | 2016
Fair value of plan assets January 1 | $ | 9,766 |  |  | $ | 9,266 |  |  | $ | 7,794 |  |  | $ | 7,204 |  |  | $ | 1,019 |  |  | $ | 1,913 |
Actual return on plan assets | 1,723 |  |  | 941 |  |  | 677 |  |  | 898 |  |  | 161 |  |  | 138 |
Company contributions, net | 58 |  |  | 63 |  |  | 226 |  |  | 424 |  |  | (4 | ) |  | 68 |
Effects of exchange rate changes | — |  |  | — |  |  | 843 |  |  | (546 | ) |  | — |  |  | — |
Benefits paid | (651 | ) |  | (504 | ) |  | (198 | ) |  | (193 | ) |  | (62 | ) |  | (108 | )
Settlements | — |  |  | — |  |  | (17 | ) |  | (21 | ) |  | — |  |  | — |
Assets no longer restricted to the payment of postretirement benefits (1) | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | (992 | )
Other | — |  |  | — |  |  | 14 |  |  | 28 |  |  | — |  |  | — |
Fair value of plan assets December 31 | $ | 10,896 |  |  | $ | 9,766 |  |  | $ | 9,339 |  |  | $ | 7,794 |  |  | $ | 1,114 |  |  | $ | 1,019 |
Benefit obligation January 1 | $ | 10,849 |  |  | $ | 9,723 |  |  | $ | 8,372 |  |  | $ | 7,733 |  |  | $ | 1,922 |  |  | $ | 1,810 |
Service cost | 312 |  |  | 282 |  |  | 252 |  |  | 238 |  |  | 57 |  |  | 54 |
Interest cost | 454 |  |  | 456 |  |  | 172 |  |  | 204 |  |  | 81 |  |  | 82 |
Actuarial losses (gains) (2) | 881 |  |  | 854 |  |  | (7 | ) |  | 938 |  |  | (87 | ) |  | 77 |
Benefits paid | (651 | ) |  | (504 | ) |  | (198 | ) |  | (193 | ) |  | (62 | ) |  | (108 | )
Effects of exchange rate changes | — |  |  | — |  |  | 916 |  |  | (576 | ) |  | 3 |  |  | 2 |
Plan amendments | — |  |  | — |  |  | (22 | ) |  | — |  |  | — |  |  | — |
Curtailments | 15 |  |  | 15 |  |  | (3 | ) |  | (15 | ) |  | — |  |  | 1 |
Termination benefits | 44 |  |  | 23 |  |  | 4 |  |  | 4 |  |  | 8 |  |  | 4 |
Settlements | — |  |  | — |  |  | (17 | ) |  | (21 | ) |  | — |  |  | — |
Other | — |  |  | — |  |  | 14 |  |  | 60 |  |  | — |  |  | — |
Benefit obligation December 31 | $ | 11,904 |  |  | $ | 10,849 |  |  | $ | 9,483 |  |  | $ | 8,372 |  |  | $ | 1,922 |  |  | $ | 1,922 |
Funded status December 31 | $ | (1,008 | ) |  | $ | (1,083 | ) |  | $ | (144 | ) |  | $ | (578 | ) |  | $ | (808 | ) |  | $ | (903 | )
Recognized as: |  |  |  |  |  |  |  |  |  |  |
Other assets | $ | — |  |  | $ | — |  |  | $ | 828 |  |  | $ | 451 |  |  | $ | — |  |  | $ | — |
Accrued and other current liabilities | (59 | ) |  | (50 | ) |  | (17 | ) |  | (7 | ) |  | (11 | ) |  | (11 | )
Other noncurrent liabilities | (949 | ) |  | (1,033 | ) |  | (955 | ) |  | (1,022 | ) |  | (797 | ) |  | (892 | )
(1) As a result of certain allowable administrative actions that occurred in June 2016, $992 million of plan assets previously restricted for the payment of other postretirement benefits became available to fund certain other health and welfare benefits. (2) Actuarial losses in 2017 and 2016 primarily reflect changes in discount rates.
Schedule of Accumulated and Projected Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block] | Information related to the funded status of selected pension plans at December 31 is as follows:
| U.S. |  | International
| 2017 |  | 2016 |  | 2017 |  | 2016
Pension plans with a projected benefit obligation in excess of plan assets |  |  |  |  |  |  |
Projected benefit obligation | $ | 11,904 |  |  | $ | 10,849 |  |  | $ | 3,323 |  |  | $ | 5,486 |
Fair value of plan assets | 10,896 |  |  | 9,766 |  |  | 2,352 |  |  | 4,457 |
Pension plans with an accumulated benefit obligation in excess of plan assets |  |  |  |  |  |  |
Accumulated benefit obligation | $ | 676 |  |  | $ | 9,807 |  |  | $ | 2,120 |  |  | $ | 2,692 |
Fair value of plan assets | — |  |  | 9,057 |  |  | 1,346 |  |  | 1,898 |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
Summary of Changes in Fair Value of Company's Level 3 Pension Plan Assets | The table below provides a summary of the changes in fair value, including transfers in and/or out, of all financial assets measured at fair value using significant unobservable inputs (Level 3) for the Company’s pension plan assets:
| 2017 |  | 2016
| Insurance Contracts |  | Real Estate |  | Other |  | Total |  | Insurance Contracts |  | Real Estate |  | Other |  | Total
U.S. Pension Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Balance January 1 | $ | — |  |  | $ | — |  |  | $ | 18 |  |  | $ | 18 |  |  | $ | — |  |  | $ | — |  |  | $ | 23 |  |  | $ | 23 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Relating to assets still held at December 31 | — |  |  | — |  |  | (2 | ) |  | (2 | ) |  | — |  |  | — |  |  | (3 | ) |  | (3 | )
Relating to assets sold during the year | — |  |  | — |  |  | 4 |  |  | 4 |  |  | — |  |  | — |  |  | 4 |  |  | 4 |
Purchases and sales, net | — |  |  | — |  |  | (5 | ) |  | (5 | ) |  | — |  |  | — |  |  | (6 | ) |  | (6 | )
Balance December 31 | $ | — |  |  | $ | — |  |  | $ | 15 |  |  | $ | 15 |  |  | $ | — |  |  | $ | — |  |  | $ | 18 |  |  | $ | 18 |
International Pension Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Balance January 1 | $ | 412 |  |  | $ | 4 |  |  | $ | 1 |  |  | $ | 417 |  |  | $ | 393 |  |  | $ | 5 |  |  | $ | 2 |  |  | $ | 400 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Relating to assets still held at December 31 | 52 |  |  | — |  |  | — |  |  | 52 |  |  | (9 | ) |  | 1 |  |  | — |  |  | (8 | )
Purchases and sales, net | 5 |  |  | (2 | ) |  | — |  |  | 3 |  |  | 2 |  |  | (2 | ) |  | (1 | ) |  | (1 | )
Transfers into Level 3 | 1 |  |  | — |  |  | — |  |  | 1 |  |  | 26 |  |  | — |  |  | — |  |  | 26 |
Balance December 31 | $ | 470 |  |  | $ | 2 |  |  | $ | 1 |  |  | $ | 473 |  |  | $ | 412 |  |  | $ | 4 |  |  | $ | 1 |  |  | $ | 417 |
Summary of Expected Benefit Payments | Expected benefit payments are as follows:
| U.S. Pension Benefits |  | International Pension Benefits |  | Other Postretirement Benefits
2018 | $ | 609 |  |  | $ | 222 |  |  | $ | 96 |
2019 | 638 |  |  | 205 |  |  | 101 |
2020 | 650 |  |  | 217 |  |  | 104 |
2021 | 663 |  |  | 225 |  |  | 109 |
2022 | 683 |  |  | 243 |  |  | 113 |
2023 — 2027 | 3,760 |  |  | 1,326 |  |  | 623 |
Components of Other Comprehensive Income | The following amounts were reflected as components of OCI:
| Pension Plans |  | Other Postretirement Benefit Plans
| U.S. |  | International |
Years Ended December 31 | 2017 |  | 2016 |  | 2015 |  | 2017 |  | 2016 |  | 2015 |  | 2017 |  | 2016 |  | 2015
Net (loss) gain arising during the period | $ | (19 | ) |  | $ | (743 | ) |  | $ | 73 |  |  | $ | 309 |  |  | $ | (380 | ) |  | $ | (66 | ) |  | $ | 170 |  |  | $ | (45 | ) |  | $ | 209 |
Prior service (cost) credit arising during the period | (13 | ) |  | (10 | ) |  | (13 | ) |  | 22 |  |  | (2 | ) |  | (4 | ) |  | (31 | ) |  | (19 | ) |  | 511 |
| $ | (32 | ) |  | $ | (753 | ) |  | $ | 60 |  |  | $ | 331 |  |  | $ | (382 | ) |  | $ | (70 | ) |  | $ | 139 |  |  | $ | (64 | ) |  | $ | 720 |
Net loss amortization included in benefit cost | $ | 180 |  |  | $ | 119 |  |  | $ | 214 |  |  | $ | 98 |  |  | $ | 87 |  |  | $ | 118 |  |  | $ | 1 |  |  | $ | 3 |  |  | $ | 5 |
Prior service (credit) cost amortization included in benefit cost | (53 | ) |  | (55 | ) |  | (56 | ) |  | (11 | ) |  | (11 | ) |  | (14 | ) |  | (98 | ) |  | (106 | ) |  | (64 | )
| $ | 127 |  |  | $ | 64 |  |  | $ | 158 |  |  | $ | 87 |  |  | $ | 76 |  |  | $ | 104 |  |  | $ | (97 | ) |  | $ | (103 | ) |  | $ | (59 | )
Summary of Weighted Average Assumptions Used in Determining Pension Plan and U.S. Pension and Other Postretirement Benefit Plan Information | The Company reassesses its benefit plan assumptions on a regular basis. The weighted average assumptions used in determining U.S. pension and other postretirement benefit plan and international pension plan information are as follows:
| U.S. Pension and Other Postretirement Benefit Plans |  | International Pension Plans
December 31 | 2017 |  |  | 2016 |  |  | 2015 |  |  | 2017 |  |  | 2016 |  |  | 2015 |
Net periodic benefit cost |  |  |  |  |  |  |  |  |  |  |
Discount rate | 4.30 | % |  | 4.70 | % |  | 4.20 | % |  | 2.20 | % |  | 2.80 | % |  | 2.70 | %
Expected rate of return on plan assets | 8.70 | % |  | 8.60 | % |  | 8.50 | % |  | 5.10 | % |  | 5.60 | % |  | 5.70 | %
Salary growth rate | 4.30 | % |  | 4.30 | % |  | 4.40 | % |  | 2.90 | % |  | 2.90 | % |  | 2.90 | %
Benefit obligation |  |  |  |  |  |  |  |  |  |  |
Discount rate | 3.70 | % |  | 4.30 | % |  | 4.80 | % |  | 2.10 | % |  | 2.20 | % |  | 2.80 | %
Salary growth rate | 4.30 | % |  | 4.30 | % |  | 4.30 | % |  | 2.90 | % |  | 2.90 | % |  | 2.90 | %
Summary of Health Care Cost Trend Rate Assumptions for Other Postretirement Benefit Plans | The health care cost trend rate assumptions for other postretirement benefit plans are as follows:
December 31 | 2017 |  | 2016
Health care cost trend rate assumed for next year | 7.2 | % |  | 7.4 | %
Rate to which the cost trend rate is assumed to decline | 4.5 | % |  | 4.5 | %
Year that the trend rate reaches the ultimate trend rate | 2032 |  |  | 2032 |
One Percentage Point Change in Health Care Cost Trend Rate | A one percentage point change in the health care cost trend rate would have had the following effects:
| One Percentage Point
| Increase |  | Decrease
Effect on total service and interest cost components | $ | 13 |  |  | $ | (11 | )
Effect on benefit obligation | 125 |  |  | (104 | )
Pension Plan |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
Schedule of Allocation of Plan Assets [Table Text Block] | The fair values of the Company’s pension plan assets at December 31 by asset category are as follows:
| Fair Value Measurements Using |  | Fair Value Measurements Using
| Quoted Prices In Active Markets for Identical Assets (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total |  | Quoted Prices In Active Markets for Identical Assets (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total
| 2017 |  |  |  | 2016 |  |
U.S. Pension Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and cash equivalents | $ | 6 |  |  | $ | — |  |  | $ | — |  |  | $ | 6 |  |  | $ | 2 |  |  | $ | 2 |  |  | $ | — |  |  | $ | 4 |
Investment funds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Developed markets equities | 390 |  |  | — |  |  | — |  |  | 390 |  |  | 521 |  |  | — |  |  | — |  |  | 521 |
Emerging markets equities | 138 |  |  | — |  |  | — |  |  | 138 |  |  | 104 |  |  | — |  |  | — |  |  | 104 |
Equity securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Developed markets | 2,743 |  |  | — |  |  | — |  |  | 2,743 |  |  | 2,521 |  |  | — |  |  | — |  |  | 2,521 |
Fixed income securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Government and agency obligations | — |  |  | 757 |  |  | — |  |  | 757 |  |  | — |  |  | 475 |  |  | — |  |  | 475 |
Corporate obligations | — |  |  | 900 |  |  | — |  |  | 900 |  |  | — |  |  | 660 |  |  | — |  |  | 660 |
Mortgage and asset-backed securities | — |  |  | 240 |  |  | — |  |  | 240 |  |  | — |  |  | 239 |  |  | — |  |  | 239 |
Other investments | — |  |  | — |  |  | 15 |  |  | 15 |  |  | — |  |  | — |  |  | 18 |  |  | 18 |
Net assets in fair value hierarchy | $ | 3,277 |  |  | $ | 1,897 |  |  | $ | 15 |  |  | $ | 5,189 |  |  | $ | 3,148 |  |  | $ | 1,376 |  |  | $ | 18 |  |  | $ | 4,542 |
Investments measured at NAV (1) |  |  |  |  |  |  | 5,707 |  |  |  |  |  |  |  |  | 5,224 |
Plan assets at fair value |  |  |  |  |  |  | $ | 10,896 |  |  |  |  |  |  |  |  | $ | 9,766 |
International Pension Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and cash equivalents | $ | 54 |  |  | $ | 19 |  |  | $ | — |  |  | $ | 73 |  |  | $ | 42 |  |  | $ | 11 |  |  | $ | — |  |  | $ | 53 |
Investment funds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Developed markets equities | 562 |  |  | 3,326 |  |  | — |  |  | 3,888 |  |  | 187 |  |  | 2,846 |  |  | — |  |  | 3,033 |
Emerging markets equities | 62 |  |  | 176 |  |  | — |  |  | 238 |  |  | 24 |  |  | 148 |  |  | — |  |  | 172 |
Government and agency obligations | 249 |  |  | 2,095 |  |  | — |  |  | 2,344 |  |  | 123 |  |  | 1,904 |  |  | — |  |  | 2,027 |
Corporate obligations | 5 |  |  | 329 |  |  | — |  |  | 334 |  |  | 2 |  |  | 282 |  |  | — |  |  | 284 |
Fixed income obligations | 7 |  |  | 4 |  |  | — |  |  | 11 |  |  | 6 |  |  | 3 |  |  | — |  |  | 9 |
Real estate (2) | — |  |  | 1 |  |  | 2 |  |  | 3 |  |  | — |  |  | 3 |  |  | 4 |  |  | 7 |
Equity securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Developed markets | 660 |  |  | — |  |  | — |  |  | 660 |  |  | 565 |  |  | — |  |  | — |  |  | 565 |
Fixed income securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Government and agency obligations | 2 |  |  | 266 |  |  | — |  |  | 268 |  |  | 2 |  |  | 235 |  |  | — |  |  | 237 |
Corporate obligations | 1 |  |  | 118 |  |  | — |  |  | 119 |  |  | — |  |  | 92 |  |  | — |  |  | 92 |
Mortgage and asset-backed securities | — |  |  | 55 |  |  | — |  |  | 55 |  |  | — |  |  | 50 |  |  | — |  |  | 50 |
Other investments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Insurance contracts (3) | — |  |  | 67 |  |  | 470 |  |  | 537 |  |  | — |  |  | 59 |  |  | 412 |  |  | 471 |
Other | — |  |  | 6 |  |  | 1 |  |  | 7 |  |  | 1 |  |  | 4 |  |  | 1 |  |  | 6 |
Net assets in fair value hierarchy | $ | 1,602 |  |  | $ | 6,462 |  |  | $ | 473 |  |  | $ | 8,537 |  |  | $ | 952 |  |  | $ | 5,637 |  |  | $ | 417 |  |  | $ | 7,006 |
Investments measured at NAV (1) |  |  |  |  |  |  | 802 |  |  |  |  |  |  |  |  | 788 |
Plan assets at fair value |  |  |  |  |  |  | $ | 9,339 |  |  |  |  |  |  |  |  | $ | 7,794 |
(1) | Certain investments that were measured at net asset value (NAV) per share or its equivalent as a practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets at December 31, 2017 and 2016.
(2) | The plans’ Level 3 investments in real estate funds are generally valued by market appraisals of the underlying investments in the funds.
(3) | The plans’ Level 3 investments in insurance contracts are generally valued using a crediting rate that approximates market returns and invest in underlying securities whose market values are unobservable and determined using pricing models, discounted cash flow methodologies, or similar techniques.
Other Postretirement Benefits |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
Schedule of Allocation of Plan Assets [Table Text Block] | The fair values of the Company’s other postretirement benefit plan assets at December 31 by asset category are as follows:
| Fair Value Measurements Using |  | Fair Value Measurements Using
| Quoted Prices In Active Markets for Identical Assets (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total |  | Quoted Prices In Active Markets for Identical Assets (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total
| 2017 |  |  |  | 2016 |  |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash and cash equivalents | $ | 97 |  |  | $ | — |  |  | $ | — |  |  | $ | 97 |  |  | $ | 125 |  |  | $ | — |  |  | $ | — |  |  | $ | 125 |
Investment funds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Developed markets equities | 37 |  |  | — |  |  | — |  |  | 37 |  |  | 48 |  |  | — |  |  | — |  |  | 48 |
Emerging markets equities | 13 |  |  | — |  |  | — |  |  | 13 |  |  | 10 |  |  | — |  |  | — |  |  | 10 |
Government and agency obligations | 1 |  |  | — |  |  | — |  |  | 1 |  |  | 1 |  |  | — |  |  | — |  |  | 1 |
Equity securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Developed markets | 256 |  |  | — |  |  | — |  |  | 256 |  |  | 231 |  |  | — |  |  | — |  |  | 231 |
Fixed income securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Government and agency obligations | — |  |  | 71 |  |  | — |  |  | 71 |  |  | — |  |  | 43 |  |  | — |  |  | 43 |
Corporate obligations | — |  |  | 84 |  |  | — |  |  | 84 |  |  | — |  |  | 60 |  |  | — |  |  | 60 |
Mortgage and asset-backed securities | — |  |  | 23 |  |  | — |  |  | 23 |  |  | — |  |  | 22 |  |  | — |  |  | 22 |
Net assets in fair value hierarchy | $ | 404 |  |  | $ | 178 |  |  | $ | — |  |  | $ | 582 |  |  | $ | 415 |  |  | $ | 125 |  |  | $ | — |  |  | $ | 540 |
Investments measured at NAV (1) |  |  |  |  |  |  | 532 |  |  |  |  |  |  |  |  | 479 |
Plan assets at fair value |  |  |  |  |  |  | $ | 1,114 |  |  |  |  |  |  |  |  | $ | 1,019 |
(1) | Certain investments that were measured at net asset value (NAV) per share or its equivalent as a practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets at December 31, 2017 and 2016.

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- Definition Tabular disclosure of accumulated and projected benefit obligations and fair value of plan assets for pension plans where the benefit obligations exceed the fair value of plan assets. + References No definition available. + Details
Name: | mrk_ScheduleofAccumulatedandProjectedBenefitObligationinExcessofFairValueofPlanAssetsTableTextBlock
Namespace Prefix: | mrk_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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- Definition Tabular disclosure of the change in the benefit obligation, fair value of plan assets, and funded status of pension plans or other employee benefit plans. + 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 (a)(b)(c) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall. + 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 (d)(5) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the assumptions used to determine for pension plans and/or other employee benefit plans the benefit obligation and net benefit cost, including assumed discount rates, rate increase in compensation increase, and expected long-term rates of return on plan assets. + 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 (k) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the changes in plan assets and benefit obligations recognized in other comprehensive income (loss) during the period. + References No definition available. + Details
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- Definition Tabular disclosure of the effect of a one-percentage-point increase and the effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs and the accumulated postretirement benefit obligation for health care benefits. + 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 (m) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the effect of fair value measurements using significant unobservable inputs (Level 3) on changes in plan assets of pension plans and/or other employee benefit plans for the period. + 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 (d)(4) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter. + 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 (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the assumed health care cost trend rates for the next year used to measure the expected cost of benefits covered by the plans, including the ultimate trend rate(s) and when that rate is expected to be achieved. + 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 (l) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + 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) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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