Selected Condensed Consolidating Financial Statements of Parent, Issuer, Guarantors and Non-Guarantors - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019
Current Assets:
Cash and cash equivalents	$ 291.5	$ 151.6
Accounts receivable	2,083.2	2,193.2
Inventories	2,137.7	2,107.5
Other current assets	490.2	496.2
Assets held for sale	3.3	25.8
Total current assets	5,005.9	4,974.3
Property, plant and equipment, net	10,922.6	11,189.5
Goodwill	7,270.5	7,285.6
Intangibles, net	3,749.4	4,059.5
Restricted assets held by special purpose entities	1,269.2	1,274.3
Prepaid pension asset	305.9	224.7
Other assets	1,754.1	1,148.8
Total Assets	30,277.6	30,156.7
Current liabilities:
Current portion of debt	213.1	561.1
Accounts payable	1,513.5	1,831.8
Accrued compensation and benefits	377.2	470.4
Other current liabilities	683.1	571.8
Total current liabilities	2,786.9	3,435.1
Long-term debt due after one year	9,840.3	9,502.3
Pension liabilities, net of current portion	271.3	294.0
Postretirement benefit liabilities, net of current portion	151.9	162.1
Non-recourse liabilities held by special purpose entities	1,138.7	1,145.2
Deferred income taxes	2,888.2	2,878.0
Other long-term liabilities	1,468.8	1,053.9
Redeemable noncontrolling interests	1.6	1.9
Total stockholders’ equity	11,713.1	11,669.9	$ 11,827.7
Noncontrolling interests	16.8	14.3
Total equity	11,729.9	11,684.2	$ 11,841.3
Total Liabilities and Equity	30,277.6	30,156.7
Parent [Member]
Current Assets:
Other current assets	0.5
Total current assets	0.5
Investments in consolidated subsidiaries	12,158.9	11,973.6
Total Assets	12,159.4	11,973.6
Current liabilities:
Accrued compensation and benefits	0.2	0.3
Intercompany payables	446.1	303.4
Total current liabilities	446.3	303.7
Total stockholders’ equity	11,713.1	11,669.9
Total equity	11,713.1	11,669.9
Total Liabilities and Equity	12,159.4	11,973.6
Issuer [Member]
Current Assets:
Other current assets		1.2
Intercompany receivables	24.0	227.7
Total current assets	24.0	228.9
Intercompany notes receivable	154.9	155.0
Investments in consolidated subsidiaries	18,891.4	18,524.2
Other assets	91.4	67.8
Total Assets	19,161.7	18,975.9
Current liabilities:
Current portion of debt	79.9	135.3
Accounts payable	1.1	0.7
Other current liabilities	51.8	18.6
Intercompany payables	57.7
Total current liabilities	190.5	154.6
Long-term debt due after one year	6,706.4	6,608.0
Intercompany notes payable	753.3	636.3
Other long-term liabilities	35.3	12.9
Total stockholders’ equity	11,476.2	11,564.1
Total equity	11,476.2	11,564.1
Total Liabilities and Equity	19,161.7	18,975.9
Guarantor Subsidiaries [Member]
Current Assets:
Cash and cash equivalents	178.4	17.8
Accounts receivable	38.9	31.1
Inventories	239.9	254.3
Other current assets	6.3	11.8
Intercompany receivables	0.3
Total current assets	463.8	315.0
Property, plant and equipment, net	14.8	18.9
Goodwill	1,158.6	1,158.6
Intangibles, net	1,409.9	1,485.0
Intercompany notes receivable	149.8	156.9
Investments in consolidated subsidiaries	19,827.1	20,103.6
Other assets	233.8	185.3
Total Assets	23,257.8	23,423.3
Current liabilities:
Current portion of debt		108.9
Accounts payable	24.2	31.3
Accrued compensation and benefits	14.5	14.5
Other current liabilities	107.7	83.8
Intercompany payables	470.6	1,052.9
Total current liabilities	617.0	1,291.4
Long-term debt due after one year	1,972.0	1,982.9
Intercompany notes payable	2,068.0	2,390.5
Pension liabilities, net of current portion	141.6	147.6
Postretirement benefit liabilities, net of current portion	25.2	25.7
Deferred income taxes	310.0	278.9
Other long-term liabilities	152.5	131.2
Total stockholders’ equity	17,971.5	17,175.1
Total equity	17,971.5	17,175.1
Total Liabilities and Equity	23,257.8	23,423.3
Non-Guarantor Subsidiaries [Member]
Current Assets:
Cash and cash equivalents	113.1	133.8
Accounts receivable	2,092.7	2,201.7
Inventories	1,897.8	1,853.2
Other current assets	483.4	483.2
Intercompany receivables	1,372.8	1,128.6
Assets held for sale	3.3	25.8
Total current assets	5,963.1	5,826.3
Property, plant and equipment, net	10,907.8	11,170.6
Goodwill	6,111.9	6,127.0
Intangibles, net	2,339.5	2,574.5
Restricted assets held by special purpose entities	1,269.2	1,274.3
Prepaid pension asset	305.9	224.7
Intercompany notes receivable	2,821.3	3,026.8
Other assets	1,515.6	971.8
Total Assets	31,234.3	31,196.0
Current liabilities:
Current portion of debt	133.2	316.9
Accounts payable	1,536.6	1,839.4
Accrued compensation and benefits	362.5	455.6
Other current liabilities	523.6	469.4
Intercompany payables	422.7
Total current liabilities	2,978.6	3,081.3
Long-term debt due after one year	1,161.9	911.4
Intercompany notes payable	304.7	311.9
Pension liabilities, net of current portion	129.7	146.4
Postretirement benefit liabilities, net of current portion	126.7	136.4
Non-recourse liabilities held by special purpose entities	1,138.7	1,145.2
Deferred income taxes	2,664.9	2,675.2
Other long-term liabilities	1,281.0	909.8
Redeemable noncontrolling interests	1.6	1.9
Total stockholders’ equity	21,429.7	21,862.2
Noncontrolling interests	16.8	14.3
Total equity	21,446.5	21,876.5
Total Liabilities and Equity	31,234.3	31,196.0
Eliminations [Member]
Current Assets:
Accounts receivable	(48.4)	(39.6)
Intercompany receivables	(1,397.1)	(1,356.3)
Total current assets	(1,445.5)	(1,395.9)
Intercompany notes receivable	(3,126.0)	(3,338.7)
Investments in consolidated subsidiaries	(50,877.4)	(50,601.4)
Other assets	(86.7)	(76.1)
Total Assets	(55,535.6)	(55,412.1)
Current liabilities:
Accounts payable	(48.4)	(39.6)
Intercompany payables	(1,397.1)	(1,356.3)
Total current liabilities	(1,445.5)	(1,395.9)
Intercompany notes payable	(3,126.0)	(3,338.7)
Deferred income taxes	(86.7)	(76.1)
Total stockholders’ equity	(50,877.4)	(50,601.4)
Total equity	(50,877.4)	(50,601.4)
Total Liabilities and Equity	$ (55,535.6)	$ (55,412.1)