| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | Merck & Co., Inc. |
| Entity Central Index Key | 0000310158 |
| Pay vs Performance Disclosure | 6 Months Ended | 12 Months Ended | |||
| Dec. 31, 2021 | Jun. 30, 2021 | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | |
| Pay vs Performance Disclosure [Table] | |||||
| Pay vs Performance [Table Text Block] | Pay Versus Performance Table The following table* summarizes the SCT compensation and CAP for the CEO(s) and the average non-CEO Summary for CEO (Davis) Summary (Frazier) Compensation to CEO (Davis) (4) Compensation (Frazier) (4) Average Non-CEO Average to Non-CEO NEOs (4) Value of Initial Fixed $100 Fiscal Total (5) Peer Group (6) GAAP Net Income ($000’s) Non-GAAP (7) 2022 (1) $18,650,093 — $52,474,235 $8,362,603 $22,297,770 $141.10 $138.10 $14,519,000 $7.48 2021 (2) 13,722,121 $15,196,920 14,390,893 $13,328,924 6,616,111 6,911,156 94.50 130.80 12,345,000 $5.37 2020 (3) — 22,088,429 10,578,487 6,041,722 3,582,756 92.80 107.10 4,519,000 $2.97 (1) Non-CEO d Ms (2) Non-CEO (3) Non-CEO (4) See following table for additional details on the calculation of the CAP value. (5) Total Shareholder Return (“TSR”) assumes an initial $100 investment in Merck stock beginni n S-K. (6) Peer Group TSR assumes an initial $100 investment in Merck’s primary peer group (market cap-weighted). (7) The SEC requires the disclosure of a company selected measure, representing the most important financial metric used for determining CAP for the current fiscal year. As described in more detail on page 70, the selected measure for 2022 is non-GAAP non-GAAP non-GAAP *Compensation shown is rounded to the nearest dollar. The following table* provides additional information on how CAP for each reporting year was determined, starting with SCT compensation and applying each of the required adjustments, as applicable, in accordance with the PVP rules. Summary Value of (1) Value of Equity Value of (2) Fair Value of (3) Year-Over-Year (4) Year-Over- (5) Value of (6) Compensation CEO (Davis) 2022 $18,650,093 $180,259 $12,393,581 $280,085 $26,824,642 $14,171,478 $3,931,065 $1,190,712 $52,474,235 2021 13,722,121 235,640 9,084,579 265,823 10,649,030 (669,339 ) (661,118 ) 404,596 14,390,893 CEO (Frazier) 2021 15,196,920 0 10,615,096 418,183 12,443,073 (2,633,787 ) (2,435,189 ) 954,819 13,328,924 2020 22,088,429 2,288,641 15,502,597 379,037 17,150,711 (5,340,113 ) (7,290,425 ) 1,382,086 10,578,487 Average Non-CEO NEOs 2022 8,362,603 42,041 5,514,804 122,447 9,133,936 6,336,440 3,346,846 552,343 22,297,770 2021 6,616,111 107,732 4,261,734 122,147 4,829,729 (247,588 ) (208,749 ) 168,972 6,911,156 2020 6,041,722 498,315 3,518,845 157,683 3,892,938 (1,222,908 ) (1,583,911 ) 314,391 3,582,756 (1) Represents the aggregate change in actuarial present value of the NEOs’ accrued benefits under the Company’s pension plans. The change in pension value for Mr. Frazier is negative in 2021, primarily due to age and an increase in discount rates. In accordance with SEC rules, a $0 value is reported rather than a negative amount. (2) These amounts represent the present value of expected pension benefit accrual earned in the current year and reflects assumptions used for financial statement reporting purposes. Does not reflect the change in the present value of the accumulated pension benefit due to changes in assumptions such as discount rate from year to year. (3) These amounts represent the fair value as of the indicated fiscal year-end (4) These amounts represent the change in fair value during the indicated fiscal year of each stock and option award that was granted in a prior fiscal year and that remained outstanding and unvested as of the last day of the indicated fiscal year, calculated in accordance with the methodology used for financial reporting purposes and, for awards subject to performance-based vesting conditions, based on an estimate of the probable outcome of such performance-based vesting conditions as of the last day of the fiscal year. (5) These amounts represent the change in fair value, measured from the prior fiscal year-end (6) These amounts represent the dollar value of any dividends or other earnings accrued or paid on stock or option awards in the applicable fiscal year or for awards that vested in the fiscal year, prior to the vesting date, that are not otherwise reflected in the fair value of such awards or included in any other component of total compensation for the applicable fiscal year. * Compensation shown is rounded to the nearest dollar. | ||||
| Company Selected Measure Name | non-GAAP EPS | ||||
| Named Executive Officers, Footnote [Text Block] | (1) Non-CEO d Ms (2) Non-CEO (3) Non-CEO | ||||
| Peer Group Issuers, Footnote [Text Block] | Peer Group TSR assumes an initial $100 investment in Merck’s primary peer group (market cap-weighted). | ||||
| Adjustment To PEO Compensation, Footnote [Text Block] | The following table* provides additional information on how CAP for each reporting year was determined, starting with SCT compensation and applying each of the required adjustments, as applicable, in accordance with the PVP rules. Summary Value of (1) Value of Equity Value of (2) Fair Value of (3) Year-Over-Year (4) Year-Over- (5) Value of (6) Compensation CEO (Davis) 2022 $18,650,093 $180,259 $12,393,581 $280,085 $26,824,642 $14,171,478 $3,931,065 $1,190,712 $52,474,235 2021 13,722,121 235,640 9,084,579 265,823 10,649,030 (669,339 ) (661,118 ) 404,596 14,390,893 CEO (Frazier) 2021 15,196,920 0 10,615,096 418,183 12,443,073 (2,633,787 ) (2,435,189 ) 954,819 13,328,924 2020 22,088,429 2,288,641 15,502,597 379,037 17,150,711 (5,340,113 ) (7,290,425 ) 1,382,086 10,578,487 Average Non-CEO NEOs 2022 8,362,603 42,041 5,514,804 122,447 9,133,936 6,336,440 3,346,846 552,343 22,297,770 2021 6,616,111 107,732 4,261,734 122,147 4,829,729 (247,588 ) (208,749 ) 168,972 6,911,156 2020 6,041,722 498,315 3,518,845 157,683 3,892,938 (1,222,908 ) (1,583,911 ) 314,391 3,582,756 (1) Represents the aggregate change in actuarial present value of the NEOs’ accrued benefits under the Company’s pension plans. The change in pension value for Mr. Frazier is negative in 2021, primarily due to age and an increase in discount rates. In accordance with SEC rules, a $0 value is reported rather than a negative amount. (2) These amounts represent the present value of expected pension benefit accrual earned in the current year and reflects assumptions used for financial statement reporting purposes. Does not reflect the change in the present value of the accumulated pension benefit due to changes in assumptions such as discount rate from year to year. (3) These amounts represent the fair value as of the indicated fiscal year-end (4) These amounts represent the change in fair value during the indicated fiscal year of each stock and option award that was granted in a prior fiscal year and that remained outstanding and unvested as of the last day of the indicated fiscal year, calculated in accordance with the methodology used for financial reporting purposes and, for awards subject to performance-based vesting conditions, based on an estimate of the probable outcome of such performance-based vesting conditions as of the last day of the fiscal year. (5) These amounts represent the change in fair value, measured from the prior fiscal year-end (6) These amounts represent the dollar value of any dividends or other earnings accrued or paid on stock or option awards in the applicable fiscal year or for awards that vested in the fiscal year, prior to the vesting date, that are not otherwise reflected in the fair value of such awards or included in any other component of total compensation for the applicable fiscal year. * Compensation shown is rounded to the nearest dollar. | ||||
| Non-PEO NEO Average Total Compensation Amount | $ 8,362,603 | $ 6,616,111 | $ 6,041,722 | ||
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 22,297,770 | 6,911,156 | 3,582,756 | ||
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | The following table* provides additional information on how CAP for each reporting year was determined, starting with SCT compensation and applying each of the required adjustments, as applicable, in accordance with the PVP rules. Summary Value of (1) Value of Equity Value of (2) Fair Value of (3) Year-Over-Year (4) Year-Over- (5) Value of (6) Compensation CEO (Davis) 2022 $18,650,093 $180,259 $12,393,581 $280,085 $26,824,642 $14,171,478 $3,931,065 $1,190,712 $52,474,235 2021 13,722,121 235,640 9,084,579 265,823 10,649,030 (669,339 ) (661,118 ) 404,596 14,390,893 CEO (Frazier) 2021 15,196,920 0 10,615,096 418,183 12,443,073 (2,633,787 ) (2,435,189 ) 954,819 13,328,924 2020 22,088,429 2,288,641 15,502,597 379,037 17,150,711 (5,340,113 ) (7,290,425 ) 1,382,086 10,578,487 Average Non-CEO NEOs 2022 8,362,603 42,041 5,514,804 122,447 9,133,936 6,336,440 3,346,846 552,343 22,297,770 2021 6,616,111 107,732 4,261,734 122,147 4,829,729 (247,588 ) (208,749 ) 168,972 6,911,156 2020 6,041,722 498,315 3,518,845 157,683 3,892,938 (1,222,908 ) (1,583,911 ) 314,391 3,582,756 (1) Represents the aggregate change in actuarial present value of the NEOs’ accrued benefits under the Company’s pension plans. The change in pension value for Mr. Frazier is negative in 2021, primarily due to age and an increase in discount rates. In accordance with SEC rules, a $0 value is reported rather than a negative amount. (2) These amounts represent the present value of expected pension benefit accrual earned in the current year and reflects assumptions used for financial statement reporting purposes. Does not reflect the change in the present value of the accumulated pension benefit due to changes in assumptions such as discount rate from year to year. (3) These amounts represent the fair value as of the indicated fiscal year-end (4) These amounts represent the change in fair value during the indicated fiscal year of each stock and option award that was granted in a prior fiscal year and that remained outstanding and unvested as of the last day of the indicated fiscal year, calculated in accordance with the methodology used for financial reporting purposes and, for awards subject to performance-based vesting conditions, based on an estimate of the probable outcome of such performance-based vesting conditions as of the last day of the fiscal year. (5) These amounts represent the change in fair value, measured from the prior fiscal year-end (6) These amounts represent the dollar value of any dividends or other earnings accrued or paid on stock or option awards in the applicable fiscal year or for awards that vested in the fiscal year, prior to the vesting date, that are not otherwise reflected in the fair value of such awards or included in any other component of total compensation for the applicable fiscal year. * Compensation shown is rounded to the nearest dollar. | ||||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | Relationship Between CAP and TSR The chart below illustrates the relationship between the CEO CAP and average non-CEO non-CEO non-CEO non-CEO | ||||
| Compensation Actually Paid vs. Net Income [Text Block] | Relationship Between CAP and Net Income The chart below illustrates the relationship between the CEO CAP and average non-CEO non-CEO non-CEO non-CEO | ||||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | Relationship Between CAP and the Company-Selected Measure The SEC requires the disclosure of a company-selected measure, defined as the most important financial metric used for determining CAP for the current fiscal year. For 2022, we consider non-GAAP non-GAAP non-CEO 3-year non-GAAP 1-year non-GAAP The chart below illustrates the relationship between the CEO CAP and average non-CEO non-GAAP is non-CEO non-CEO non-CEO | ||||
| Tabular List [Table Text Block] | Most Important Metrics Used to Link Pay and Performance In accordance with the PVP rules, the most important performance metrics used to link our NEOs’ pay to performance in 2022 are listed below. These metrics align with the measures used in our Company Scorecard, as described on page 53, and our PSU Program, as described on page 56. These metrics help translate our strategic priorities into operational terms that enable us to measure and track our progress against annual operating goals and long-term strategic drivers of sustainable value creation, aligning the pay of our executives to company performance. Although stock price performance, as reflected by our TSR, is not a metric used in our current programs to set or evaluate the level of pay for our executives and, therefore, is not included in the list below, it directly impacts the value of long-term incentives granted to our NEOs. Company Scorecard Metrics PSU Program Metrics Revenue Relative Total Shareholder Return Pre-Tax Earnings Per Share Pipeline | ||||
| Total Shareholder Return Amount | $ 141.1 | 94.5 | 92.8 | ||
| Peer Group Total Shareholder Return Amount | 138.1 | 130.8 | 107.1 | ||
| Net Income (Loss) | $ 14,519,000,000 | $ 12,345,000,000 | $ 4,519,000,000 | ||
| Company Selected Measure Amount | 7.48 | 5.37 | 2.97 | ||
| Measure [Axis]: 1 | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Measure Name | Revenue | ||||
| Measure [Axis]: 2 | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Measure Name | Pre-Tax Income | ||||
| Measure [Axis]: 3 | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Measure Name | Pipeline | ||||
| Measure [Axis]: 4 | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Measure Name | Relative Total Shareholder Return | ||||
| Measure [Axis]: 5 | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Measure Name | Earnings Per Share | ||||
| Measure [Axis]: 6 | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Non-GAAP Measure Description [Text Block] | The SEC requires the disclosure of a company selected measure, representing the most important financial metric used for determining CAP for the current fiscal year. As described in more detail on page 70, the selected measure for 2022 is non-GAAP non-GAAP non-GAAP | ||||
| Mr. Davis [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| PEO Total Compensation Amount | $ 18,650,093 | $ 13,722,121 | |||
| PEO Actually Paid Compensation Amount | $ 52,474,235 | 14,390,893 | |||
| PEO Name | Mr. Davis | Mr. Davis | |||
| Mr. Frazier [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| PEO Total Compensation Amount | 15,196,920 | $ 22,088,429 | |||
| PEO Actually Paid Compensation Amount | 13,328,924 | $ 10,578,487 | |||
| PEO Name | Mr. Frazier | Mr. Frazier | |||
| PEO [Member] | Mr. Davis [Member] | Deduct: Pension Adjustments Pension Value In Summary Compensation Table [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | $ 180,259 | 235,640 | |||
| PEO [Member] | Mr. Davis [Member] | Deduct: Equity Awards Value In Summary Compensation Table (Grant Date Value) [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 12,393,581 | 9,084,579 | |||
| PEO [Member] | Mr. Davis [Member] | Change In Fair Value As Of Vesting Date Of Current Year Awards Vested During Current Year [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 3,931,065 | (661,118) | |||
| PEO [Member] | Mr. Davis [Member] | Dividends Or Other Earnings Paid On Equity Awards Not Otherwise Reflected In Fair Value [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 1,190,712 | 404,596 | |||
| PEO [Member] | Mr. Davis [Member] | Value of Pension Benefits Per CAP [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 280,085 | 265,823 | |||
| PEO [Member] | Mr. Davis [Member] | Fair Value of Equity Compensation Granted in Current Year [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 26,824,642 | 10,649,030 | |||
| PEO [Member] | Mr. Davis [Member] | Year Over Year Change in Fair Value of Unvested Equity [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 14,171,478 | (669,339) | |||
| PEO [Member] | Mr. Frazier [Member] | Deduct: Pension Adjustments Pension Value In Summary Compensation Table [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 0 | $ 2,288,641 | |||
| PEO [Member] | Mr. Frazier [Member] | Deduct: Equity Awards Value In Summary Compensation Table (Grant Date Value) [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 10,615,096 | 15,502,597 | |||
| PEO [Member] | Mr. Frazier [Member] | Change In Fair Value As Of Vesting Date Of Current Year Awards Vested During Current Year [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | (2,435,189) | (7,290,425) | |||
| PEO [Member] | Mr. Frazier [Member] | Dividends Or Other Earnings Paid On Equity Awards Not Otherwise Reflected In Fair Value [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 954,819 | 1,382,086 | |||
| PEO [Member] | Mr. Frazier [Member] | Value of Pension Benefits Per CAP [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 418,183 | 379,037 | |||
| PEO [Member] | Mr. Frazier [Member] | Fair Value of Equity Compensation Granted in Current Year [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 12,443,073 | 17,150,711 | |||
| PEO [Member] | Mr. Frazier [Member] | Year Over Year Change in Fair Value of Unvested Equity [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | (2,633,787) | (5,340,113) | |||
| Non-PEO NEO [Member] | Deduct: Pension Adjustments Pension Value In Summary Compensation Table [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 42,041 | 107,732 | 498,315 | ||
| Non-PEO NEO [Member] | Deduct: Equity Awards Value In Summary Compensation Table (Grant Date Value) [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 5,514,804 | 4,261,734 | 3,518,845 | ||
| Non-PEO NEO [Member] | Change In Fair Value As Of Vesting Date Of Current Year Awards Vested During Current Year [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 3,346,846 | (208,749) | (1,583,911) | ||
| Non-PEO NEO [Member] | Dividends Or Other Earnings Paid On Equity Awards Not Otherwise Reflected In Fair Value [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 552,343 | 168,972 | 314,391 | ||
| Non-PEO NEO [Member] | Value of Pension Benefits Per CAP [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 122,447 | 122,147 | 157,683 | ||
| Non-PEO NEO [Member] | Fair Value of Equity Compensation Granted in Current Year [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | 9,133,936 | 4,829,729 | 3,892,938 | ||
| Non-PEO NEO [Member] | Year Over Year Change in Fair Value of Unvested Equity [Member] | |||||
| Pay vs Performance Disclosure [Table] | |||||
| Adjustment to Compensation Amount | $ 6,336,440 | $ (247,588) | $ (1,222,908) | ||
