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Segments of Business (Details) $ in Millions, $ in Millions |  | 3 Months Ended | 6 Months Ended | 9 Months Ended
--- | --- | --- | --- | ---
May 23, 2018 USD ($) | May 23, 2018 CAD ($) | Sep. 30, 2018 USD ($) country | Jun. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Jun. 30, 2017 USD ($) | Mar. 31, 2017 USD ($) | Sep. 30, 2018 USD ($) segment country | Sep. 30, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2017 CAD ($)
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | $ 53,075 |  | $ 52,061 |  |  | $ 105,682 | $ 103,112 |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Total operating profit |  |  | 689 |  | 239 |  |  | 772 | 872 |  |
Corporate Expenses, Net (6) |  |  | (167) |  | (108) |  |  | (290) | (217) |  |
Interest Expense |  |  | (66) |  | (69) |  |  | (127) | (137) |  |
Income from Continuing Operations Before Income Taxes |  |  | 587 |  | 178 |  |  | $ 593 | 636 |  |
Number of reportable segments | segment |  |  |  |  |  |  |  | 3 |  |  |
Pre-tax credits related to LIFO accounting |  |  |  |  |  |  |  | $ 43 | 3 |  |
Goodwill and asset impairment charges |  |  | 0 | $ 570 | 350 |  |  | 570 | 350 |  |
Pre-tax restructuring and asset impairment charges |  |  | 82 |  | 236 |  |  | 178 | 236 |  |
After-tax restructuring and asset impairment charges |  |  | 67 |  | 197 |  |  | 152 |  |  |
Loss from equity method investment in Change Healthcare |  |  | 56 |  | 61 |  |  | 112 | 181 |  |
U.S. Pharmaceutical and Specialty Solutions |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Pre-tax credits related to LIFO accounting |  |  | $ 22 |  | 29 |  |  | 43 | 3 |  |
Goodwill and asset impairment charges |  |  |  |  |  |  |  | $ 0 |  |  |
European Pharmaceutical Solutions |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Number of countries in which entity segment operates | country |  |  | 13 |  |  |  |  | 13 |  |  |
Goodwill and asset impairment charges |  |  |  | $ 570 |  |  |  | $ 570 |  |  |
Medical-Surgical Solutions |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Goodwill and asset impairment charges |  |  |  |  |  |  |  | 0 |  |  |
Other |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Goodwill and asset impairment charges |  |  |  |  |  |  |  | 0 |  |  |
Operating Segments |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | $ 53,075 |  | 52,061 |  |  | 105,682 | 103,112 |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Total operating profit |  |  | $ 820 |  | $ 355 |  |  | $ 1,010 | $ 990 |  |
Revenue derived from services, percentage (less than) |  |  | 1.00% |  | 1.00% |  |  | 1.00% | 1.00% |  |
Operating Segments | U.S. Pharmaceutical and Specialty Solutions |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | $ 41,610 |  | $ 40,603 |  |  | $ 82,587 | $ 80,885 |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Total operating profit |  |  | 610 |  | 710 |  |  | 1,153 | 1,185 |  |
Proceeds from legal settlements |  |  |  |  |  |  |  | (35) |  |  |
Operating Segments | European Pharmaceutical Solutions |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | 6,639 |  | 6,773 |  |  | 13,574 | 13,155 |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Total operating profit |  |  | $ 10 |  | $ (547) |  |  | $ (550) | $ (512) |  |
Revenue derived from services, percentage (less than) |  |  | 10.00% |  | 10.00% |  |  | 10.00% | 10.00% |  |
Goodwill and asset impairment charges |  |  |  |  | $ 236 |  |  | $ 570 |  |  |
Pre-tax restructuring and asset impairment charges |  |  |  |  |  |  |  |  | $ 236 |  |
After-tax restructuring and asset impairment charges |  |  |  |  |  |  |  |  | 197 |  |
After-tax goodwill impairment |  |  |  |  |  |  |  | 570 |  |  |
Operating Segments | Medical-Surgical Solutions |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | $ 1,948 |  | 1,660 |  |  | 3,651 | 3,193 |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Total operating profit |  |  | $ 105 |  | $ 118 |  |  | $ 198 | $ 226 |  |
Revenue derived from services, percentage (less than) |  |  | 1.00% |  | 1.00% |  |  | 1.00% | 1.00% |  |
Operating Segments | Other |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | $ 2,878 |  | $ 3,025 |  |  | $ 5,870 | $ 5,879 |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Total operating profit |  |  | 95 |  | 74 |  |  | 209 | 91 |  |
Joint Venture | Change Healthcare, LLC (“Change Healthcare”) |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Ownership interest in the joint venture (percent) |  |  |  |  |  |  | 70.00% |  |  |  |
Loss from equity method investment in Change Healthcare |  |  | $ 56 |  | 61 |  |  | $ 112 | 181 |  |
Core MTS Businesses | Change Healthcare, LLC (“Change Healthcare”) | Operating Segments | Other |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Gain from sale of business, pre-tax |  |  |  |  |  | $ 37 | $ 3,947 |  |  |  |
Gain from sale of business, after tax |  |  |  |  |  | $ 22 | $ 3,018 |  |  |  |
Core MTS Businesses | Joint Venture |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Ownership interest in the joint venture (percent) |  |  | 70.00% |  |  |  |  | 70.00% |  |  |
United States |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | $ 43,774 |  | 42,558 |  |  | $ 86,664 | 84,669 |  |
Foreign |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Total Revenues |  |  | 9,301 |  | 9,503 |  |  | 19,018 | 18,443 |  |
Third Party Seller of Rexall Health | Rexall Health | CANADA |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Net restructuring charges recognized |  |  |  |  |  |  |  | 97 |  |  |
Proceeds from prior acquisitions | $ 97 | $ 125 |  |  |  |  |  |  |  | $ 119 | $ 147
Strategic Growth Initiative Plan |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Net restructuring charges recognized |  |  | 53 |  |  |  |  | 111 |  |  |
Strategic Growth Initiative Plan | U.S. Pharmaceutical and Specialty Solutions |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Net restructuring charges recognized |  |  | 5 |  |  |  |  | 13 |  |  |
Strategic Growth Initiative Plan | Medical-Surgical Solutions |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Net restructuring charges recognized |  |  | 6 |  |  |  |  | 18 |  |  |
Strategic Growth Initiative Plan | Other |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Net restructuring charges recognized |  |  | 42 |  |  |  |  | 80 |  |  |
Net restructuring charges recognized, after tax |  |  | 37 |  |  |  |  | 76 |  |  |
Mckesson Europe Reporting Unit | Operating Segments | European Pharmaceutical Solutions |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Goodwill and asset impairment charges |  |  |  |  | 350 |  |  |  | 350 |  |
After-tax goodwill impairment |  |  |  |  | $ 350 |  |  |  | $ 350 |  |
Tax Receivable Agreement (“TRA”) | Change Healthcare, LLC (“Change Healthcare”) | Other |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Gain on derecognition of liability, pre-tax |  |  | 90 |  |  |  |  |  |  |  |
Gain on derecognition of liability, after tax |  |  | 66 |  |  |  |  |  |  |  |
Opioid-Related Case |  |  |  |  |  |  |  |  |  |  |
Operating profit |  |  |  |  |  |  |  |  |  |  |
Litigation expenses and other-related costs |  |  | 43 |  |  |  |  | 59 |  |  |
Litigation expenses and other-related costs, after tax |  |  | $ 32 |  |  |  |  | $ 48 |  |  |

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