Business Combinations	9 Months Ended
Dec. 31, 2017
Business Combinations [Abstract]
Business Combinations	Business Combinations 2018 Acquisitions RxCrossroads On January 2, 2018, we completed our acquisition of RxCrossroads for the net purchase consideration of $724 million, which was funded from cash on hand. RxCrossroads is headquartered in Louisville, Kentucky and provides tailored services to pharmaceutical and biotechnology manufacturers. This acquisition will enhance our existing commercialization solutions for manufacturers of branded, specialty, generic and biosimilar drugs. The financial results of the acquired business will be included in our North America pharmaceutical distribution and services business within our Distribution Solutions segment commencing the fourth quarter of 2018. CoverMyMeds LLC (“CMM”) On April 3, 2017, we completed our acquisition of CMM for the net purchase consideration of $1.3 billion, which was funded from cash on hand. The cash consideration was initially paid into an escrow account prior to our 2017 fiscal year end, and was included in “Other Noncurrent Assets” within our consolidated balance sheet at March 31, 2017. CMM is headquartered in Columbus, Ohio and provides electronic prior authorization solutions to pharmacies, providers, payers, and pharmaceutical manufacturers. The financial results of CMM are included in our North America pharmaceutical distribution and services business within our Distribution Solutions segment since the acquisition date. Pursuant to the agreement, McKesson may pay up to an additional $160 million of contingent consideration based on CMM’s financial performance for 2018 and 2019. As a result, we recorded a liability for this remaining contingent consideration at its estimated fair value of $113 million as of the acquisition date on our condensed consolidated balance sheet. The contingent consideration was estimated using a Monte Carlo simulation, which utilized Level 3 inputs under the fair value measurement and disclosure guidance, including estimated financial forecasts. The contingent liability is re-measured at fair value at each reporting date until the liability is extinguished with changes in fair value being recorded to our statements of operations. There was no material change in the fair value of this contingent liability during the third quarter and the first nine months of 2018. The initial fair value of this contingent consideration was a non-cash investing activity. During the third quarter and first nine months of 2018, we recorded certain measurement period adjustments to the provisional fair value of assets acquired and liabilities assumed as of the acquisition date. The adjusted provisional fair value of assets acquired and liabilities assumed as of the acquisition date, excluding goodwill and intangibles, was $52 million and $7 million. Approximately $870 million of the adjusted preliminary purchase price allocation has been assigned to goodwill, which reflects the expected future benefits of certain synergies and intangible assets that do not qualify for separate recognition. Included in the adjusted preliminary purchase price allocation are acquired identifiable intangibles of $487 million primarily representing customer relationships with a weighted average life of 17 years. Amounts recognized as of the acquisition date are provisional and subject to change within the measurement period as our fair value assessments are finalized. Other During the first nine months of 2018, we also completed our acquisitions of intraFUSION, Inc. (“intraFUSION”), BDI Pharma, LLC (“BDI”) and Uniprix Group (“Uniprix”) for net cash consideration of $480 million, which was funded from cash on hand. intraFUSION is a healthcare management company based in Houston, Texas providing services to physician office infusion centers. BDI is a plasma distributor headquartered in Columbia, South Carolina. We acquired the Uniprix banner which serves 375 independent pharmacies in Quebec, Canada. The adjusted provisional fair value of assets and liabilities recognized as of the acquisition dates for these three acquisitions included approximately $235 million of goodwill and $118 million of identifiable intangibles, primarily representing customer relationships. The amounts as of the acquisition date are provisional and subject to change within the measurement period as our fair value assessments are finalized. The financial results of intraFUSION, BDI and Uniprix are included within our Distribution Solutions segment since the acquisition dates. The fair value of acquired intangibles from these acquisitions was primarily determined by applying the income approach, using several significant unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs. 2017 Acquisitions Rexall Health On December 28, 2016, we completed our acquisition of Rexall Health which operates approximately 450 retail pharmacies in Canada, primarily in Ontario and Western Canada. The initial net cash purchase consideration of $2.9 billion Canadian dollars (or, approximately $2.1 billion) was funded from cash on hand. As part of the transaction, McKesson agreed to divest 27 stores that the Competition Bureau of Canada (the “Bureau”) identified during its review of the transaction. During the first nine months of 2018, we completed the sales of all 27 stores and received net cash proceeds of $116 million Canadian dollars (or, approximately $94 million) from a third-party buyer. We also received $147 million Canadian dollars (or, approximately $119 million) in cash from the third-party seller of Rexall Health as the settlement of the post-closing purchase price adjustment related to these store divestitures. No gain or loss was recognized from the sales of these stores. The financial results of Rexall Health are included in our North America pharmaceutical distribution and services business within our Distribution Solutions segment since the acquisition date. The fair value measurements of assets and liabilities assumed of Rexall Health as of the acquisition date were finalized upon completion of the measurement period. At December 31, 2017, the final amounts of fair value recognized for the assets acquired and liabilities assumed as of the acquisition date, excluding goodwill and intangibles, were $560 million and $210 million. Approximately $948 million of the final purchase price allocation was assigned to goodwill, which primarily reflects the expected future benefits of certain synergies and intangible assets that do not qualify for separate recognition. Included in the final purchase price allocation were acquired identifiable intangibles of $872 million, net of intangibles classified as held for sale, primarily representing trade names with a weighted average life of 19 years and customer relationships with a weighted average life of 19 years. The fair value of acquired intangibles from the acquisition was primarily determined by applying the income approach, using several significant unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs. Other During the first nine months of 2017, we completed our acquisitions of Vantage Oncology Holdings, LLC (“Vantage”), Biologics, Inc., UDG Healthcare Plc and other businesses for net cash payments of $2.0 billion. Other Acquisitions During the last two years, we also completed other acquisitions within both of our operating segments. Financial results for our business acquisitions have been included in our consolidated financial statements since their respective acquisition dates. Purchase prices for our business acquisitions have been allocated based on estimated fair values at the date of acquisition. Goodwill recognized for our business acquisitions is generally not expected to be deductible for tax purposes. However, if we acquire the assets of a company, the goodwill may be deductible for tax purposes.

Business Combinations

2018 Acquisitions

RxCrossroads

On January 2, 2018, we completed our acquisition of RxCrossroads for the net purchase consideration of $724 million, which was funded from cash on hand. RxCrossroads is headquartered in Louisville, Kentucky and provides tailored services to pharmaceutical and biotechnology manufacturers. This acquisition will enhance our existing commercialization solutions for manufacturers of branded, specialty, generic and biosimilar drugs. The financial results of the acquired business will be included in our North America pharmaceutical distribution and services business within our Distribution Solutions segment commencing the fourth quarter of 2018.

CoverMyMeds LLC (“CMM”)

On April 3, 2017, we completed our acquisition of CMM for the net purchase consideration of $1.3 billion, which was funded from cash on hand. The cash consideration was initially paid into an escrow account prior to our 2017 fiscal year end, and was included in “Other Noncurrent Assets” within our consolidated balance sheet at March 31, 2017. CMM is headquartered in Columbus, Ohio and provides electronic prior authorization solutions to pharmacies, providers, payers, and pharmaceutical manufacturers. The financial results of CMM are included in our North America pharmaceutical distribution and services business within our Distribution Solutions segment since the acquisition date.

Pursuant to the agreement, McKesson may pay up to an additional $160 million of contingent consideration based on CMM’s financial performance for 2018 and 2019. As a result, we recorded a liability for this remaining contingent consideration at its estimated fair value of $113 million as of the acquisition date on our condensed consolidated balance sheet. The contingent consideration was estimated using a Monte Carlo simulation, which utilized Level 3 inputs under the fair value measurement and disclosure guidance, including estimated financial forecasts. The contingent liability is re-measured at fair value at each reporting date until the liability is extinguished with changes in fair value being recorded to our statements of operations. There was no material change in the fair value of this contingent liability during the third quarter and the first nine months of 2018. The initial fair value of this contingent consideration was a non-cash investing activity.

During the third quarter and first nine months of 2018, we recorded certain measurement period adjustments to the provisional fair value of assets acquired and liabilities assumed as of the acquisition date. The adjusted provisional fair value of assets acquired and liabilities assumed as of the acquisition date, excluding goodwill and intangibles, was $52 million and $7 million. Approximately $870 million of the adjusted preliminary purchase price allocation has been assigned to goodwill, which reflects the expected future benefits of certain synergies and intangible assets that do not qualify for separate recognition. Included in the adjusted preliminary purchase price allocation are acquired identifiable intangibles of $487 million primarily representing customer relationships with a weighted average life of 17 years. Amounts recognized as of the acquisition date are provisional and subject to change within the measurement period as our fair value assessments are finalized.

Other

During the first nine months of 2018, we also completed our acquisitions of intraFUSION, Inc. (“intraFUSION”), BDI Pharma, LLC (“BDI”) and Uniprix Group (“Uniprix”) for net cash consideration of $480 million, which was funded from cash on hand. intraFUSION is a healthcare management company based in Houston, Texas providing services to physician office infusion centers. BDI is a plasma distributor headquartered in Columbia, South Carolina. We acquired the Uniprix banner which serves 375 independent pharmacies in Quebec, Canada. The adjusted provisional fair value of assets and liabilities recognized as of the acquisition dates for these three acquisitions included approximately $235 million of goodwill and $118 million of identifiable intangibles, primarily representing customer relationships. The amounts as of the acquisition date are provisional and subject to change within the measurement period as our fair value assessments are finalized. The financial results of intraFUSION, BDI and Uniprix are included within our Distribution Solutions segment since the acquisition dates.

The fair value of acquired intangibles from these acquisitions was primarily determined by applying the income approach, using several significant unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs.

2017 Acquisitions

Rexall Health

On December 28, 2016, we completed our acquisition of Rexall Health which operates approximately 450 retail pharmacies in Canada, primarily in Ontario and Western Canada. The initial net cash purchase consideration of $2.9 billion Canadian dollars (or, approximately $2.1 billion) was funded from cash on hand. As part of the transaction, McKesson agreed to divest 27 stores that the Competition Bureau of Canada (the “Bureau”) identified during its review of the transaction. During the first nine months of 2018, we completed the sales of all 27 stores and received net cash proceeds of $116 million Canadian dollars (or, approximately $94 million) from a third-party buyer. We also received $147 million Canadian dollars (or, approximately $119 million) in cash from the third-party seller of Rexall Health as the settlement of the post-closing purchase price adjustment related to these store divestitures. No gain or loss was recognized from the sales of these stores. The financial results of Rexall Health are included in our North America pharmaceutical distribution and services business within our Distribution Solutions segment since the acquisition date.

The fair value measurements of assets and liabilities assumed of Rexall Health as of the acquisition date were finalized upon completion of the measurement period. At December 31, 2017, the final amounts of fair value recognized for the assets acquired and liabilities assumed as of the acquisition date, excluding goodwill and intangibles, were $560 million and $210 million. Approximately $948 million of the final purchase price allocation was assigned to goodwill, which primarily reflects the expected future benefits of certain synergies and intangible assets that do not qualify for separate recognition. Included in the final purchase price allocation were acquired identifiable intangibles of $872 million, net of intangibles classified as held for sale, primarily representing trade names with a weighted average life of 19 years and customer relationships with a weighted average life of 19 years.

The fair value of acquired intangibles from the acquisition was primarily determined by applying the income approach, using several significant unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs.

Other

During the first nine months of 2017, we completed our acquisitions of Vantage Oncology Holdings, LLC (“Vantage”), Biologics, Inc., UDG Healthcare Plc and other businesses for net cash payments of $2.0 billion.

Other Acquisitions

During the last two years, we also completed other acquisitions within both of our operating segments. Financial results for our business acquisitions have been included in our consolidated financial statements since their respective acquisition dates. Purchase prices for our business acquisitions have been allocated based on estimated fair values at the date of acquisition.

Goodwill recognized for our business acquisitions is generally not expected to be deductible for tax purposes. However, if we acquire the assets of a company, the goodwill may be deductible for tax purposes.