Goodwill and Other Intangible Assets - Schedule of Change in the Carrying Value of Goodwill by Reportable Segment (Details) $ in Thousands	3 Months Ended
Dec. 31, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill	$ 6,705,507
Foreign currency translation	2,257
Goodwill	6,707,764
Operating segments \| Pharmaceutical Distribution Services
Goodwill [Roll Forward]
Goodwill	4,852,775
Foreign currency translation	0
Goodwill	4,852,775
Operating segments \| Other
Goodwill [Roll Forward]
Goodwill	1,852,732
Foreign currency translation	2,257
Goodwill	$ 1,854,989

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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