Business Segment Information (Schedule of Segment Reporting Information) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
Segment Reporting Information [Line Items]
Sales	$ 2,945.1	$ 2,502.0	$ 5,939.3	$ 4,877.2
Operating income (loss)	561.9	548.5	1,084.9	1,087.6
Depreciation and amortization			668.2	653.0
Equity affiliates' income	120.8	69.8	268.6	139.1
Total assets	27,449.7		27,449.7		$ 26,859.2
Operating Segments
Segment Reporting Information [Line Items]
Sales	2,945.1	2,502.0	5,939.3	4,877.2
Operating income (loss)	561.9	534.9	1,084.9	1,074.0
Depreciation and amortization	335.9	329.3	668.2	653.0
Equity affiliates' income	120.8	69.8	268.6	139.1
Total assets	27,449.7		27,449.7		26,859.2
Americas | Operating Segments
Segment Reporting Information [Line Items]
Sales	1,186.6	1,056.1	2,410.7	1,989.1
Operating income (loss)	275.5	263.4	542.7	489.2
Depreciation and amortization	153.7	153.3	309.0	305.1
Equity affiliates' income	20.1	32.3	54.3	54.6
Total assets	7,801.9		7,801.9		7,092.5
Asia | Operating Segments
Segment Reporting Information [Line Items]
Sales	751.2	697.5	1,531.6	1,415.0
Operating income (loss)	203.6	198.5	424.7	413.3
Depreciation and amortization	111.8	109.7	222.6	217.6
Equity affiliates' income	6.2	7.1	12.8	15.9
Total assets	7,712.6		7,712.6		7,349.4
Europe | Operating Segments
Segment Reporting Information [Line Items]
Sales	738.6	558.4	1,482.8	1,101.9
Operating income (loss)	116.4	132.9	215.6	270.4
Depreciation and amortization	50.3	51.0	100.1	100.3
Equity affiliates' income	23.3	12.6	37.2	27.5
Total assets	3,933.9		3,933.9		3,830.3
Middle East and India | Operating Segments
Segment Reporting Information [Line Items]
Sales	28.9	26.2	52.6	45.7
Operating income (loss)	4.8	6.7	9.6	10.7
Depreciation and amortization	6.9	6.6	13.0	12.7
Equity affiliates' income	71.1	16.1	163.4	37.3
Total assets	2,676.8		2,676.8		800.6
Corporate and other | Operating Segments
Segment Reporting Information [Line Items]
Sales	239.8	163.8	461.6	325.5
Operating income (loss)	(38.4)	(66.6)	(107.7)	(109.6)
Depreciation and amortization	13.2	8.7	23.5	17.3
Equity affiliates' income	0.1	$ 1.7	0.9	$ 3.8
Total assets	$ 5,324.5		$ 5,324.5		$ 7,786.4