Acquisition	3 Months Ended
Dec. 31, 2017
Business Combinations [Abstract]
Acquisition	Acquisitions NEVSCO In December 2017, the Company acquired Northeast Veterinary Supply Company ("NEVSCO") for $70.0 million in cash, subject to a final working capital adjustment. NEVSCO is an independent, regional distributor of veterinary pharmaceuticals and medical supplies serving primarily the northeast region of the United States and is expected to strengthen MWI Animal Health's ("MWI") support of independent veterinary practices and provide even greater value and care to current and future animal health customers. NEVSCO has been included within the MWI operating segment. The purchase price has been preliminarily allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. The preliminary allocation is pending the finalization of the appraisals of intangible assets and the finalization of working capital account balances. There can be no assurance that the estimated amounts recorded will represent the final purchase price allocation. The purchase price currently exceeds the estimated fair value of the net tangible and intangible assets acquired by $30.4 million, which was allocated to goodwill. The estimated fair value of accounts receivable, inventory, and accounts payable and accrued expenses acquired was $7.9 million, $6.7 million, and $4.7 million, respectively. The estimated fair value of the intangible assets acquired of $29.8 million primarily consisted of customer relationships, which the Company is amortizing over the estimated useful life of 15 years. Goodwill and intangibles resulting from the acquisition are expected to be deductible for income tax purposes. H.D. Smith As previously disclosed in the Company's Annual Report on Form 10-K for the fiscal year ended September 30, 2017, the Company entered into a definitive agreement on November 20, 2017 to acquire H.D. Smith Holding Company ("H.D. Smith"), the largest independent pharmaceutical wholesaler in the United States. On January 2, 2018, the Company completed the acquisition of H.D. Smith for $815.0 million in cash, subject to a final working capital adjustment. The Company funded the acquisition through the issuance of new long-term debt (see Note 5). H.D. Smith is the largest privately held national wholesaler, which provides full-line distribution of brand, generic, and specialty drugs, as well as high-value services and solutions for manufacturers and healthcare providers. H.D. Smith customers include retail pharmacies, specialty pharmacies, long-term care facilities, institutional/hospital systems, and independent physicians and clinics. The acquisition strengthens the Company's core business, expands and enhances its strategic scale in pharmaceutical distribution, and expands the Company's support for independent community pharmacies. Profarma and Specialty Joint Venture As previously disclosed in the Company's Annual Report on Form 10-K for the fiscal year ended September 30, 2017, the Company held a minority ownership interest in Profarma Distribuidora de Produtos Farmacêuticos S.A. ("Profarma"), a leading pharmaceutical wholesaler in Brazil, and an ownership interest in a joint venture with Profarma to provide specialty distribution and services to the Brazilian marketplace. The Company has accounted for these interests as equity method investments, which have been reported in Other Assets on the Company's Consolidated Balance Sheets. In January 2018, the Company invested an additional $62.5 million in Profarma and an additional $15.6 million in the joint venture to increase its ownership interests. The additional investments give the Company controlling ownership interests in Profarma and the joint venture. The Company will consolidate the financial results of these investments in future reporting periods.

Acquisitions

NEVSCO

In December 2017, the Company acquired Northeast Veterinary Supply Company ("NEVSCO") for $70.0 million in cash, subject to a final working capital adjustment. NEVSCO is an independent, regional distributor of veterinary pharmaceuticals and medical supplies serving primarily the northeast region of the United States and is expected to strengthen MWI Animal Health's ("MWI") support of independent veterinary practices and provide even greater value and care to current and future animal health customers. NEVSCO has been included within the MWI operating segment.

The purchase price has been preliminarily allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. The preliminary allocation is pending the finalization of the appraisals of intangible assets and the finalization of working capital account balances. There can be no assurance that the estimated amounts recorded will represent the final purchase price allocation. The purchase price currently exceeds the estimated fair value of the net tangible and intangible assets acquired by $30.4 million, which was allocated to goodwill. The estimated fair value of accounts receivable, inventory, and accounts payable and accrued expenses acquired was $7.9 million, $6.7 million, and $4.7 million, respectively. The estimated fair value of the intangible assets acquired of $29.8 million primarily consisted of customer relationships, which the Company is amortizing over the estimated useful life of 15 years. Goodwill and intangibles resulting from the acquisition are expected to be deductible for income tax purposes.

H.D. Smith

As previously disclosed in the Company's Annual Report on Form 10-K for the fiscal year ended September 30, 2017, the Company entered into a definitive agreement on November 20, 2017 to acquire H.D. Smith Holding Company ("H.D. Smith"), the largest independent pharmaceutical wholesaler in the United States. On January 2, 2018, the Company completed the acquisition of H.D. Smith for $815.0 million in cash, subject to a final working capital adjustment. The Company funded the acquisition through the issuance of new long-term debt (see Note 5).

H.D. Smith is the largest privately held national wholesaler, which provides full-line distribution of brand, generic, and specialty drugs, as well as high-value services and solutions for manufacturers and healthcare providers. H.D. Smith customers include retail pharmacies, specialty pharmacies, long-term care facilities, institutional/hospital systems, and independent physicians and clinics.

The acquisition strengthens the Company's core business, expands and enhances its strategic scale in pharmaceutical distribution, and expands the Company's support for independent community pharmacies.

Profarma and Specialty Joint Venture

As previously disclosed in the Company's Annual Report on Form 10-K for the fiscal year ended September 30, 2017, the Company held a minority ownership interest in Profarma Distribuidora de Produtos Farmacêuticos S.A. ("Profarma"), a leading pharmaceutical wholesaler in Brazil, and an ownership interest in a joint venture with Profarma to provide specialty distribution and services to the Brazilian marketplace. The Company has accounted for these interests as equity method investments, which have been reported in Other Assets on the Company's Consolidated Balance Sheets. In January 2018, the Company invested an additional $62.5 million in Profarma and an additional $15.6 million in the joint venture to increase its ownership interests. The additional investments give the Company controlling ownership interests in Profarma and the joint venture. The Company will consolidate the financial results of these investments in future reporting periods.