CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net (loss) income	$ (3,399,558,000)	$ 854,135,000	$ 1,615,892,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, including amounts charged to cost of goods sold	290,744,000	321,102,000	318,483,000
Amortization, including amounts charged to interest expense	117,269,000	176,410,000	191,626,000
Provision for doubtful accounts	11,912,000	25,196,000	16,660,000
(Benefit) provision for deferred income taxes	(1,544,971,000)	28,537,000	(795,524,000)
Share-based compensation expense	74,411,000	58,874,000	62,316,000
LIFO expense (credit)	7,422,000	(22,544,000)	67,324,000
Impairment of PharMEDium assets	361,652,000	570,000,000	0
Gain on sale of an equity investment	0	(13,692,000)	0
Goodwill impairment	0	0	59,684,000
Impairment of non-customer note receivable	0	0	30,000,000
Loss on consolidation of equity investments	0	0	42,328,000
Loss on early retirement of debt	22,175,000	0	23,766,000
Other, net	(3,044,000)	(23,193,000)	(19,078,000)
Changes in operating assets and liabilities, excluding the effects of acquisitions and divestitures:
Accounts receivable	(1,628,991,000)	(1,241,890,000)	(657,770,000)
Inventories	(1,621,143,000)	(167,990,000)	(4,923,000)
Income tax receivable	(482,569,000)	(2,834,000)	4,566,000
Prepaid expenses and other assets	28,050,000	(3,899,000)	(61,777,000)
Accounts payable	3,300,832,000	1,561,048,000	859,036,000
Income taxes payable	(3,289,000)	(13,353,000)	209,899,000
Accrued expenses	524,021,000	239,688,000	(537,905,000)
Accrued litigation liability	6,198,943,000	0	0
Other liabilities	(46,826,000)	(1,572,000)	(13,215,000)
NET CASH PROVIDED BY OPERATING ACTIVITIES	2,207,040,000	2,344,023,000	1,411,388,000
INVESTING ACTIVITIES
Capital expenditures	(369,677,000)	(310,222,000)	(336,411,000)
Cost of acquired companies, net of cash acquired	0	(63,951,000)	(785,299,000)
Cost of equity investments	(56,080,000)	0	0
Proceeds on sale of property and equipment	36,364,000	1,295,000	8,100,000
Other, net	9,522,000	(2,954,000)	2,496,000
NET CASH USED IN INVESTING ACTIVITIES	(379,871,000)	(375,832,000)	(1,111,114,000)
FINANCING ACTIVITIES
Senior notes and other loan borrowings	599,480,000	506,948,000	1,314,430,000
Senior notes and other loan repayments	(598,452,000)	(510,863,000)	(681,001,000)
Borrowings under revolving and securitization credit facilities	116,946,000	640,126,000	25,129,704,000
Repayments under revolving and securitization credit facilities	(149,980,000)	(769,284,000)	(25,127,438,000)
Payment of premium on early retirement of debt	(21,448,000)	0	(22,348,000)
Purchases of common stock	(420,449,000)	(674,031,000)	(639,235,000)
Exercises of stock options	159,533,000	76,234,000	138,456,000
Cash dividends on common stock	(343,578,000)	(338,974,000)	(333,041,000)
Profarma retail equity offering	66,355,000	0	0
Tax withholdings related to restricted share vesting	(9,787,000)	(5,987,000)	(8,246,000)
Other	(2,237,000)	(10,682,000)	(14,154,000)
NET CASH USED IN FINANCING ACTIVITIES	(603,617,000)	(1,086,513,000)	(242,873,000)
INCREASE IN CASH AND CASH EQUIVALENTS	1,223,552,000	881,678,000	57,401,000
Cash and cash equivalents at beginning of year	3,374,194,000	2,492,516,000	2,435,115,000
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 4,597,746,000	$ 3,374,194,000	$ 2,492,516,000