CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 45,392,452	$ 40,466,332
Cost of goods sold	44,094,872	39,353,680
Gross profit	1,297,580	1,112,652
Operating expenses:
Distribution, selling, and administrative	656,585	558,522
Depreciation	75,362	64,907
Amortization	47,138	40,229
Employee severance, litigation, and other	40,672	30,021
Operating income	477,823	418,973
Other loss	3,097	324
Interest expense, net	42,170	35,864
Loss on early retirement of debt	0	23,766
Income before income taxes	432,556	359,019
Income tax expense (benefit)	40,803	(502,834)
Net income	391,753	861,853
Net loss attributable to noncontrolling interest	1,899	0
Net income attributable to AmerisourceBergen Corporation	$ 393,652	$ 861,853
Earnings per share:
Basic (usd per share)	$ 1.86	$ 3.95
Diluted (usd per share)	$ 1.84	$ 3.90
Weighted average common shares outstanding:
Basic (shares)	212,054	218,323
Diluted (shares)	213,969	220,822
Cash dividends declared per share of common stock (usd per share)	$ 0.4	$ 0.38