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Segment Reporting - Sales of Company's Products (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2018 | Mar. 31, 2017
Segment Reporting Information [Line Items] |  |
Sales | $ 10,037 | $ 9,434
Proceeds from sale of marketing rights | 21 | 50
Operating Segments |  |
Segment Reporting Information [Line Items] |  |
Sales | 10,068 | 9,218
Operating Segments | Total Pharmaceutical segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 8,919 | 8,185
Operating Segments | Total Pharmaceutical segment sales | Keytruda |  |
Segment Reporting Information [Line Items] |  |
Sales | 1,464 | 584
Operating Segments | Total Pharmaceutical segment sales | Emend |  |
Segment Reporting Information [Line Items] |  |
Sales | 125 | 133
Operating Segments | Total Pharmaceutical segment sales | Temodar |  |
Segment Reporting Information [Line Items] |  |
Sales | 57 | 66
Operating Segments | Total Pharmaceutical segment sales | Alliance revenue - Lynparza |  |
Segment Reporting Information [Line Items] |  |
Sales | 33 | 0
Operating Segments | Total Pharmaceutical segment sales | Gardasil/Gardasil 9 |  |
Segment Reporting Information [Line Items] |  |
Sales | 660 | 532
Operating Segments | Total Pharmaceutical segment sales | ProQuad/M-M-R II/Varivax |  |
Segment Reporting Information [Line Items] |  |
Sales | 392 | 355
Operating Segments | Total Pharmaceutical segment sales | RotaTeq |  |
Segment Reporting Information [Line Items] |  |
Sales | 193 | 224
Operating Segments | Total Pharmaceutical segment sales | Pneumovax 23 |  |
Segment Reporting Information [Line Items] |  |
Sales | 179 | 163
Operating Segments | Total Pharmaceutical segment sales | Zostavax |  |
Segment Reporting Information [Line Items] |  |
Sales | 65 | 154
Operating Segments | Total Pharmaceutical segment sales | Bridion |  |
Segment Reporting Information [Line Items] |  |
Sales | 204 | 148
Operating Segments | Total Pharmaceutical segment sales | Noxafil |  |
Segment Reporting Information [Line Items] |  |
Sales | 176 | 141
Operating Segments | Total Pharmaceutical segment sales | Invanz |  |
Segment Reporting Information [Line Items] |  |
Sales | 151 | 136
Operating Segments | Total Pharmaceutical segment sales | Cubicin |  |
Segment Reporting Information [Line Items] |  |
Sales | 98 | 96
Operating Segments | Total Pharmaceutical segment sales | Cancidas |  |
Segment Reporting Information [Line Items] |  |
Sales | 91 | 121
Operating Segments | Total Pharmaceutical segment sales | Primaxin |  |
Segment Reporting Information [Line Items] |  |
Sales | 72 | 62
Operating Segments | Total Pharmaceutical segment sales | Simponi |  |
Segment Reporting Information [Line Items] |  |
Sales | 231 | 184
Operating Segments | Total Pharmaceutical segment sales | Remicade |  |
Segment Reporting Information [Line Items] |  |
Sales | 167 | 229
Operating Segments | Total Pharmaceutical segment sales | Belsomra |  |
Segment Reporting Information [Line Items] |  |
Sales | 54 | 42
Operating Segments | Total Pharmaceutical segment sales | Isentress/Isentress HD |  |
Segment Reporting Information [Line Items] |  |
Sales | 281 | 305
Operating Segments | Total Pharmaceutical segment sales | Zepatier |  |
Segment Reporting Information [Line Items] |  |
Sales | 131 | 378
Operating Segments | Total Pharmaceutical segment sales | Zetia |  |
Segment Reporting Information [Line Items] |  |
Sales | 305 | 334
Operating Segments | Total Pharmaceutical segment sales | Vytorin |  |
Segment Reporting Information [Line Items] |  |
Sales | 167 | 241
Operating Segments | Total Pharmaceutical segment sales | Atozet |  |
Segment Reporting Information [Line Items] |  |
Sales | 73 | 49
Operating Segments | Total Pharmaceutical segment sales | Adempas |  |
Segment Reporting Information [Line Items] |  |
Sales | 68 | 84
Operating Segments | Total Pharmaceutical segment sales | Januvia |  |
Segment Reporting Information [Line Items] |  |
Sales | 880 | 839
Operating Segments | Total Pharmaceutical segment sales | Janumet |  |
Segment Reporting Information [Line Items] |  |
Sales | 544 | 496
Operating Segments | Total Pharmaceutical segment sales | NuvaRing |  |
Segment Reporting Information [Line Items] |  |
Sales | 216 | 160
Operating Segments | Total Pharmaceutical segment sales | Implanon/Nexplanon |  |
Segment Reporting Information [Line Items] |  |
Sales | 174 | 170
Operating Segments | Total Pharmaceutical segment sales | Singulair |  |
Segment Reporting Information [Line Items] |  |
Sales | 175 | 186
Operating Segments | Total Pharmaceutical segment sales | Nasonex |  |
Segment Reporting Information [Line Items] |  |
Sales | 122 | 139
Operating Segments | Total Pharmaceutical segment sales | Cozaar/Hyzaar |  |
Segment Reporting Information [Line Items] |  |
Sales | 120 | 112
Operating Segments | Total Pharmaceutical segment sales | Arcoxia |  |
Segment Reporting Information [Line Items] |  |
Sales | 83 | 103
Operating Segments | Total Pharmaceutical segment sales | Follistim AQ |  |
Segment Reporting Information [Line Items] |  |
Sales | 67 | 81
Operating Segments | Total Pharmaceutical segment sales | Dulera |  |
Segment Reporting Information [Line Items] |  |
Sales | 57 | 82
Operating Segments | Total Pharmaceutical segment sales | Fosamax |  |
Segment Reporting Information [Line Items] |  |
Sales | 55 | 61
Operating Segments | Total Pharmaceutical segment sales | Other Pharmaceutical |  |
Segment Reporting Information [Line Items] |  |
Sales | 989 | 995
Operating Segments | Total Animal Health segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 1,065 | 939
Operating Segments | Total Animal Health segment sales | Livestock |  |
Segment Reporting Information [Line Items] |  |
Sales | 652 | 578
Operating Segments | Total Animal Health segment sales | Companion Animals |  |
Segment Reporting Information [Line Items] |  |
Sales | 413 | 361
Operating Segments | Other segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 84 | 94
Other |  |
Segment Reporting Information [Line Items] |  |
Sales | (31) | 216
United States |  |
Segment Reporting Information [Line Items] |  |
Sales | 4,133 | 4,195
United States | Operating Segments |  |
Segment Reporting Information [Line Items] |  |
Sales | 4,107 | 4,138
United States | Operating Segments | Total Pharmaceutical segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 3,716 | 3,761
United States | Operating Segments | Total Pharmaceutical segment sales | Keytruda |  |
Segment Reporting Information [Line Items] |  |
Sales | 838 | 361
United States | Operating Segments | Total Pharmaceutical segment sales | Emend |  |
Segment Reporting Information [Line Items] |  |
Sales | 79 | 86
United States | Operating Segments | Total Pharmaceutical segment sales | Temodar |  |
Segment Reporting Information [Line Items] |  |
Sales | 1 | 1
United States | Operating Segments | Total Pharmaceutical segment sales | Alliance revenue - Lynparza |  |
Segment Reporting Information [Line Items] |  |
Sales | 24 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Gardasil/Gardasil 9 |  |
Segment Reporting Information [Line Items] |  |
Sales | 380 | 398
United States | Operating Segments | Total Pharmaceutical segment sales | ProQuad/M-M-R II/Varivax |  |
Segment Reporting Information [Line Items] |  |
Sales | 312 | 298
United States | Operating Segments | Total Pharmaceutical segment sales | RotaTeq |  |
Segment Reporting Information [Line Items] |  |
Sales | 151 | 178
United States | Operating Segments | Total Pharmaceutical segment sales | Pneumovax 23 |  |
Segment Reporting Information [Line Items] |  |
Sales | 112 | 114
United States | Operating Segments | Total Pharmaceutical segment sales | Zostavax |  |
Segment Reporting Information [Line Items] |  |
Sales | 16 | 109
United States | Operating Segments | Total Pharmaceutical segment sales | Bridion |  |
Segment Reporting Information [Line Items] |  |
Sales | 80 | 45
United States | Operating Segments | Total Pharmaceutical segment sales | Noxafil |  |
Segment Reporting Information [Line Items] |  |
Sales | 81 | 65
United States | Operating Segments | Total Pharmaceutical segment sales | Invanz |  |
Segment Reporting Information [Line Items] |  |
Sales | 91 | 82
United States | Operating Segments | Total Pharmaceutical segment sales | Cubicin |  |
Segment Reporting Information [Line Items] |  |
Sales | 47 | 54
United States | Operating Segments | Total Pharmaceutical segment sales | Cancidas |  |
Segment Reporting Information [Line Items] |  |
Sales | 3 | 5
United States | Operating Segments | Total Pharmaceutical segment sales | Primaxin |  |
Segment Reporting Information [Line Items] |  |
Sales | 5 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Simponi |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Remicade |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Belsomra |  |
Segment Reporting Information [Line Items] |  |
Sales | 23 | 20
United States | Operating Segments | Total Pharmaceutical segment sales | Isentress/Isentress HD |  |
Segment Reporting Information [Line Items] |  |
Sales | 128 | 143
United States | Operating Segments | Total Pharmaceutical segment sales | Zepatier |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 200
United States | Operating Segments | Total Pharmaceutical segment sales | Zetia |  |
Segment Reporting Information [Line Items] |  |
Sales | 17 | 111
United States | Operating Segments | Total Pharmaceutical segment sales | Vytorin |  |
Segment Reporting Information [Line Items] |  |
Sales | 8 | 90
United States | Operating Segments | Total Pharmaceutical segment sales | Atozet |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Adempas |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Januvia |  |
Segment Reporting Information [Line Items] |  |
Sales | 465 | 507
United States | Operating Segments | Total Pharmaceutical segment sales | Janumet |  |
Segment Reporting Information [Line Items] |  |
Sales | 192 | 195
United States | Operating Segments | Total Pharmaceutical segment sales | NuvaRing |  |
Segment Reporting Information [Line Items] |  |
Sales | 171 | 113
United States | Operating Segments | Total Pharmaceutical segment sales | Implanon/Nexplanon |  |
Segment Reporting Information [Line Items] |  |
Sales | 128 | 132
United States | Operating Segments | Total Pharmaceutical segment sales | Singulair |  |
Segment Reporting Information [Line Items] |  |
Sales | 6 | 6
United States | Operating Segments | Total Pharmaceutical segment sales | Nasonex |  |
Segment Reporting Information [Line Items] |  |
Sales | 1 | 18
United States | Operating Segments | Total Pharmaceutical segment sales | Cozaar/Hyzaar |  |
Segment Reporting Information [Line Items] |  |
Sales | 7 | 3
United States | Operating Segments | Total Pharmaceutical segment sales | Arcoxia |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 0
United States | Operating Segments | Total Pharmaceutical segment sales | Follistim AQ |  |
Segment Reporting Information [Line Items] |  |
Sales | 29 | 42
United States | Operating Segments | Total Pharmaceutical segment sales | Dulera |  |
Segment Reporting Information [Line Items] |  |
Sales | 50 | 75
United States | Operating Segments | Total Pharmaceutical segment sales | Fosamax |  |
Segment Reporting Information [Line Items] |  |
Sales | (2) | 1
United States | Operating Segments | Total Pharmaceutical segment sales | Other Pharmaceutical |  |
Segment Reporting Information [Line Items] |  |
Sales | 273 | 309
United States | Operating Segments | Total Animal Health segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 307 | 283
United States | Operating Segments | Total Animal Health segment sales | Livestock |  |
Segment Reporting Information [Line Items] |  |
Sales | 124 | 119
United States | Operating Segments | Total Animal Health segment sales | Companion Animals |  |
Segment Reporting Information [Line Items] |  |
Sales | 183 | 164
United States | Operating Segments | Other segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 84 | 94
United States | Other |  |
Segment Reporting Information [Line Items] |  |
Sales | 26 | 57
International |  |
Segment Reporting Information [Line Items] |  |
Sales | 5,904 | 5,239
International | Operating Segments |  |
Segment Reporting Information [Line Items] |  |
Sales | 5,960 | 5,080
International | Operating Segments | Total Pharmaceutical segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 5,202 | 4,424
International | Operating Segments | Total Pharmaceutical segment sales | Keytruda |  |
Segment Reporting Information [Line Items] |  |
Sales | 626 | 223
International | Operating Segments | Total Pharmaceutical segment sales | Emend |  |
Segment Reporting Information [Line Items] |  |
Sales | 46 | 47
International | Operating Segments | Total Pharmaceutical segment sales | Temodar |  |
Segment Reporting Information [Line Items] |  |
Sales | 56 | 65
International | Operating Segments | Total Pharmaceutical segment sales | Alliance revenue - Lynparza |  |
Segment Reporting Information [Line Items] |  |
Sales | 9 | 0
International | Operating Segments | Total Pharmaceutical segment sales | Gardasil/Gardasil 9 |  |
Segment Reporting Information [Line Items] |  |
Sales | 280 | 134
International | Operating Segments | Total Pharmaceutical segment sales | ProQuad/M-M-R II/Varivax |  |
Segment Reporting Information [Line Items] |  |
Sales | 80 | 57
International | Operating Segments | Total Pharmaceutical segment sales | RotaTeq |  |
Segment Reporting Information [Line Items] |  |
Sales | 42 | 45
International | Operating Segments | Total Pharmaceutical segment sales | Pneumovax 23 |  |
Segment Reporting Information [Line Items] |  |
Sales | 66 | 49
International | Operating Segments | Total Pharmaceutical segment sales | Zostavax |  |
Segment Reporting Information [Line Items] |  |
Sales | 48 | 45
International | Operating Segments | Total Pharmaceutical segment sales | Bridion |  |
Segment Reporting Information [Line Items] |  |
Sales | 124 | 102
International | Operating Segments | Total Pharmaceutical segment sales | Noxafil |  |
Segment Reporting Information [Line Items] |  |
Sales | 94 | 76
International | Operating Segments | Total Pharmaceutical segment sales | Invanz |  |
Segment Reporting Information [Line Items] |  |
Sales | 60 | 54
International | Operating Segments | Total Pharmaceutical segment sales | Cubicin |  |
Segment Reporting Information [Line Items] |  |
Sales | 51 | 41
International | Operating Segments | Total Pharmaceutical segment sales | Cancidas |  |
Segment Reporting Information [Line Items] |  |
Sales | 88 | 116
International | Operating Segments | Total Pharmaceutical segment sales | Primaxin |  |
Segment Reporting Information [Line Items] |  |
Sales | 67 | 62
International | Operating Segments | Total Pharmaceutical segment sales | Simponi |  |
Segment Reporting Information [Line Items] |  |
Sales | 231 | 184
International | Operating Segments | Total Pharmaceutical segment sales | Remicade |  |
Segment Reporting Information [Line Items] |  |
Sales | 167 | 229
International | Operating Segments | Total Pharmaceutical segment sales | Belsomra |  |
Segment Reporting Information [Line Items] |  |
Sales | 31 | 21
International | Operating Segments | Total Pharmaceutical segment sales | Isentress/Isentress HD |  |
Segment Reporting Information [Line Items] |  |
Sales | 152 | 162
International | Operating Segments | Total Pharmaceutical segment sales | Zepatier |  |
Segment Reporting Information [Line Items] |  |
Sales | 131 | 178
International | Operating Segments | Total Pharmaceutical segment sales | Zetia |  |
Segment Reporting Information [Line Items] |  |
Sales | 287 | 222
International | Operating Segments | Total Pharmaceutical segment sales | Vytorin |  |
Segment Reporting Information [Line Items] |  |
Sales | 158 | 151
International | Operating Segments | Total Pharmaceutical segment sales | Atozet |  |
Segment Reporting Information [Line Items] |  |
Sales | 73 | 49
International | Operating Segments | Total Pharmaceutical segment sales | Adempas |  |
Segment Reporting Information [Line Items] |  |
Sales | 68 | 84
International | Operating Segments | Total Pharmaceutical segment sales | Januvia |  |
Segment Reporting Information [Line Items] |  |
Sales | 416 | 332
International | Operating Segments | Total Pharmaceutical segment sales | Janumet |  |
Segment Reporting Information [Line Items] |  |
Sales | 352 | 302
International | Operating Segments | Total Pharmaceutical segment sales | NuvaRing |  |
Segment Reporting Information [Line Items] |  |
Sales | 46 | 47
International | Operating Segments | Total Pharmaceutical segment sales | Implanon/Nexplanon |  |
Segment Reporting Information [Line Items] |  |
Sales | 46 | 39
International | Operating Segments | Total Pharmaceutical segment sales | Singulair |  |
Segment Reporting Information [Line Items] |  |
Sales | 170 | 180
International | Operating Segments | Total Pharmaceutical segment sales | Nasonex |  |
Segment Reporting Information [Line Items] |  |
Sales | 121 | 121
International | Operating Segments | Total Pharmaceutical segment sales | Cozaar/Hyzaar |  |
Segment Reporting Information [Line Items] |  |
Sales | 113 | 109
International | Operating Segments | Total Pharmaceutical segment sales | Arcoxia |  |
Segment Reporting Information [Line Items] |  |
Sales | 83 | 103
International | Operating Segments | Total Pharmaceutical segment sales | Follistim AQ |  |
Segment Reporting Information [Line Items] |  |
Sales | 39 | 40
International | Operating Segments | Total Pharmaceutical segment sales | Dulera |  |
Segment Reporting Information [Line Items] |  |
Sales | 7 | 7
International | Operating Segments | Total Pharmaceutical segment sales | Fosamax |  |
Segment Reporting Information [Line Items] |  |
Sales | 57 | 60
International | Operating Segments | Total Pharmaceutical segment sales | Other Pharmaceutical |  |
Segment Reporting Information [Line Items] |  |
Sales | 717 | 688
International | Operating Segments | Total Animal Health segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 758 | 656
International | Operating Segments | Total Animal Health segment sales | Livestock |  |
Segment Reporting Information [Line Items] |  |
Sales | 529 | 459
International | Operating Segments | Total Animal Health segment sales | Companion Animals |  |
Segment Reporting Information [Line Items] |  |
Sales | 229 | 197
International | Operating Segments | Other segment sales |  |
Segment Reporting Information [Line Items] |  |
Sales | 0 | 0
International | Other |  |
Segment Reporting Information [Line Items] |  |
Sales | $ (56) | $ 159

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