CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenue	$ 45,366,777	$ 45,239,265	$ 140,649,158	$ 133,951,319
Cost of goods sold	44,141,061	44,008,026	136,804,121	129,997,744
Gross profit	1,225,716	1,231,239	3,845,037	3,953,575
Operating expenses:
Distribution, selling, and administrative	666,885	656,943	2,046,251	1,941,564
Depreciation	69,594	71,716	208,634	222,297
Amortization	25,821	35,880	85,091	131,565
Employee severance, litigation, and other	58,585	60,006	165,626	156,067
Impairment of PharMEDium assets	0	0	361,652	570,000
Operating income	404,831	406,694	977,783	932,082
Other loss (income), net	1,073	(342)	2,806	(11,739)
Interest expense, net	37,748	35,921	103,176	121,366
Loss on early retirement of debt	22,175	0	22,175	0
Income before income taxes	343,835	371,115	849,626	822,455
Income tax expense (benefit)	56,567	69,113	(595,321)	100,627
Net income	287,268	302,002	1,444,947	721,828
Net loss (income) attributable to noncontrolling interest	2,171	(43)	(7,591)	918
Net income attributable to AmerisourceBergen Corporation	$ 289,439	$ 301,959	$ 1,437,356	$ 722,746
Earnings per share:
Basic (usd per share)	$ 1.42	$ 1.44	$ 7.01	$ 3.45
Diluted (usd per share)	$ 1.41	$ 1.43	$ 6.95	$ 3.42
Weighted average common shares outstanding:
Basic (shares)	203,654	209,705	205,017	209,484
Diluted (shares)	205,544	211,161	206,714	211,151
Cash dividends declared per share of common stock (usd per share)	$ 0.42	$ 0.40	$ 1.24	$ 1.20