Redeemable Noncontrolling Interests and Noncontrolling Interests	12 Months Ended
Mar. 31, 2017
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests and Noncontrolling Interests	Redeemable Noncontrolling Interests and Noncontrolling Interests Redeemable Noncontrolling Interests In December 2014, the domination and profit and loss transfer agreement (the “Domination Agreement”) entered into between McKesson and Celesio AG (“Celesio”) became effective upon the registration in the commercial register of Celesio at the local court of Stuttgart. Upon the effectiveness of the Domination Agreement, Celesio subordinated its management to McKesson and undertook to transfer all of its annual profits to McKesson, and McKesson undertook to compensate any annual losses incurred by Celesio and to grant, subject to a potential court review, the noncontrolling shareholders of Celesio (i) an annual recurring compensation of €0.83 per Celesio share (“Compensation Amount”), (ii) a one-time dividend for Celesio’s fiscal year ended December 31, 2014 of €0.83 per Celesio share reduced accordingly for any dividend paid by Celesio in relation to its fiscal year ended December 31, 2014 (“Guaranteed Dividend”) and (iii) a right to put (“Put Right”) their Celesio shares at €22.99 per share increased annually for interest in the amount of 5 percentage points above a base rate published by the German Bundesbank semiannually, less any Compensation Amount or Guaranteed Dividend already paid in respect of the relevant time period (“Put Amount”). The Domination Agreement does not have an expiration date and can be terminated by McKesson without cause in writing no earlier than March 31, 2020. Under the Domination Agreement, the noncontrolling shareholders of Celesio ceased to participate in their percentage ownership of Celesio’s profits and losses, but instead became entitled to receive the one-time Guaranteed Dividend in December 2014 and the Compensation Amount from January 2015. As a result, during 2017, 2016 and 2015, we recorded a total attribution of net income to the noncontrolling shareholders of Celesio of $44 million, $44 million and $62 million. All amounts were recorded in our consolidated statement of operations within the caption, “Net Income Attributable to Noncontrolling Interests,” and the corresponding liability balance was recorded within other accrued liabilities on our consolidated balance sheet. Upon the effectiveness of the Domination Agreement, the noncontrolling interests in Celesio became redeemable as a result of the Put Right. Accordingly, the carrying value of noncontrolling interests related to Celesio of $1.5 billion was reclassified from “Total Equity” to “Redeemable Noncontrolling Interests” on our consolidated balance sheet during 2015. The balance of redeemable noncontrolling interests is reported at the greater of its carrying value or its maximum redemption value at each reporting date. The redemption value is the Put Amount adjusted for exchange rate fluctuations each period. At March 31, 2017 and 2016, the carrying value of redeemable noncontrolling interests of $1.33 billion and $1.41 billion exceeded the maximum redemption value of $1.21 billion and $1.28 billion. At March 31, 2017 and 2016, we owned approximately 76% of Celesio’s outstanding common shares. Appraisal Proceedings Subsequent to the Domination Agreement’s registration, certain noncontrolling shareholders of Celesio initiated appraisal proceedings (“Appraisal Proceedings”) with the Stuttgart Regional Court to challenge the adequacy of the Compensation Amount, the Guaranteed Dividend and/or the Put Amount. As long as any Appraisal Proceedings are pending, the Compensation Amount, Guaranteed Dividend and/or Put Amount will be paid as specified currently in the Domination Agreement. If any such Appraisal Proceedings result in an adjustment to the Compensation Amount, Guaranteed Dividend and/or Put Amount, Celesio Holdings would be required to make certain additional payments for any shortfall to all Celesio noncontrolling shareholders who previously received the Guaranteed Dividend, Compensation Amount and/or Put Amount. The Put Right specified in the Domination Agreement may be exercised until two months after the announcement regarding the end of the Appraisal Proceedings (“Time Limitation Period”). In addition, if the Domination Agreement is terminated after the Time Limitation Period, the Put Right may be exercised for a two-month period after the date of termination. Noncontrolling Interests In connection with our acquisition of Vantage on April 1, 2016 as described in Financial Note 4, “Business Combinations,” we recognized noncontrolling interests with a fair value of $89 million at the acquisition date. Noncontrolling interests which represent third-party equity interests in our consolidated entities, including Vantage and ClarusOne Sourcing Services LLC, were $178 million and $84 million at March 31, 2017 and 2016. During 2017, 2016 and 2015, we allocated a total of $39 million, $8 million and $5 million of net income to noncontrolling interests.

Redeemable Noncontrolling Interests and Noncontrolling Interests

Redeemable Noncontrolling Interests

In December 2014, the domination and profit and loss transfer agreement (the “Domination Agreement”) entered into between McKesson and Celesio AG (“Celesio”) became effective upon the registration in the commercial register of Celesio at the local court of Stuttgart. Upon the effectiveness of the Domination Agreement, Celesio subordinated its management to McKesson and undertook to transfer all of its annual profits to McKesson, and McKesson undertook to compensate any annual losses incurred by Celesio and to grant, subject to a potential court review, the noncontrolling shareholders of Celesio (i) an annual recurring compensation of €0.83 per Celesio share (“Compensation Amount”), (ii) a one-time dividend for Celesio’s fiscal year ended December 31, 2014 of €0.83 per Celesio share reduced accordingly for any dividend paid by Celesio in relation to its fiscal year ended December 31, 2014 (“Guaranteed Dividend”) and (iii) a right to put (“Put Right”) their Celesio shares at €22.99 per share increased annually for interest in the amount of 5 percentage points above a base rate published by the German Bundesbank semiannually, less any Compensation Amount or Guaranteed Dividend already paid in respect of the relevant time period (“Put Amount”). The Domination Agreement does not have an expiration date and can be terminated by McKesson without cause in writing no earlier than March 31, 2020.

Under the Domination Agreement, the noncontrolling shareholders of Celesio ceased to participate in their percentage ownership of Celesio’s profits and losses, but instead became entitled to receive the one-time Guaranteed Dividend in December 2014 and the Compensation Amount from January 2015. As a result, during 2017, 2016 and 2015, we recorded a total attribution of net income to the noncontrolling shareholders of Celesio of $44 million, $44 million and $62 million. All amounts were recorded in our consolidated statement of operations within the caption, “Net Income Attributable to Noncontrolling Interests,” and the corresponding liability balance was recorded within other accrued liabilities on our consolidated balance sheet.

Upon the effectiveness of the Domination Agreement, the noncontrolling interests in Celesio became redeemable as a result of the Put Right. Accordingly, the carrying value of noncontrolling interests related to Celesio of $1.5 billion was reclassified from “Total Equity” to “Redeemable Noncontrolling Interests” on our consolidated balance sheet during 2015. The balance of redeemable noncontrolling interests is reported at the greater of its carrying value or its maximum redemption value at each reporting date. The redemption value is the Put Amount adjusted for exchange rate fluctuations each period. At March 31, 2017 and 2016, the carrying value of redeemable noncontrolling interests of $1.33 billion and $1.41 billion exceeded the maximum redemption value of $1.21 billion and $1.28 billion. At March 31, 2017 and 2016, we owned approximately 76% of Celesio’s outstanding common shares.

Appraisal Proceedings

Subsequent to the Domination Agreement’s registration, certain noncontrolling shareholders of Celesio initiated appraisal proceedings (“Appraisal Proceedings”) with the Stuttgart Regional Court to challenge the adequacy of the Compensation Amount, the Guaranteed Dividend and/or the Put Amount. As long as any Appraisal Proceedings are pending, the Compensation Amount, Guaranteed Dividend and/or Put Amount will be paid as specified currently in the Domination Agreement. If any such Appraisal Proceedings result in an adjustment to the Compensation Amount, Guaranteed Dividend and/or Put Amount, Celesio Holdings would be required to make certain additional payments for any shortfall to all Celesio noncontrolling shareholders who previously received the Guaranteed Dividend, Compensation Amount and/or Put Amount. The Put Right specified in the Domination Agreement may be exercised until two months after the announcement regarding the end of the Appraisal Proceedings (“Time Limitation Period”). In addition, if the Domination Agreement is terminated after the Time Limitation Period, the Put Right may be exercised for a two-month period after the date of termination.

Noncontrolling Interests

In connection with our acquisition of Vantage on April 1, 2016 as described in Financial Note 4, “Business Combinations,” we recognized noncontrolling interests with a fair value of $89 million at the acquisition date. Noncontrolling interests which represent third-party equity interests in our consolidated entities, including Vantage and ClarusOne Sourcing Services LLC, were $178 million and $84 million at March 31, 2017 and 2016. During 2017, 2016 and 2015, we allocated a total of $39 million, $8 million and $5 million of net income to noncontrolling interests.