CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022	Sep. 30, 2021	Sep. 30, 2020
Operating activities:
Net income	$ 24.2	$ 173.9	$ 508.9	$ 321.5
Depreciation and amortization	27.0	107.6	104.0	104.2
Intangible asset impairment charge		7.7
Stock-based incentive compensation	4.2	28.6	27.2	29.3
Deferred income taxes	(179.5)	(53.5)	99.8	21.5
Gain on sale of assets	(5.6)	(3.8)	(3.6)	(11.8)
Unrealized loss on investments	(5.5)	(12.6)	(0.7)
Foreign currency transaction (gains) losses	(0.9)	6.9	(3.1)	(0.6)
Other non-cash adjustments	0.3	4.3	2.3	7.9
Changes in operating assets and liabilities:
Receivables, net	45.5	(200.4)	(128.3)	266.7
Unbilled receivables, net	(19.7)	(146.3)	62.8	65.8
Inventories, net	(139.0)	(330.8)	199.3	(242.8)
Other current assets	(13.5)	(11.5)	8.1	(17.4)
Accounts payable	(105.6)	331.7	252.1	(222.5)
Customer advances	124.9	819.3	281.3	112.3
Payroll-related obligations	(96.7)	1.5	61.2	(32.3)
Income taxes payable	190.6	71.8	(156.7)	(52.1)
Other current liabilities	3.4	7.5	6.4	(37.1)
Other long-term assets and liabilities	(28.2)	(225.8)	(100.8)	14.7
Total changes in operating assets and liabilities	(38.3)	317.0	485.4	(144.7)
Net cash provided (used) by operating activities	(163.1)	601.3	1,221.6	327.3
Investing activities:
Additions to property, plant and equipment	(39.4)	(269.5)	(104.4)	(112.3)
Additions to equipment held for rental	(3.8)	(10.2)	(10.4)	(17.9)
Acquisition of business, net of cash acquired		(19.7)	(110.6)
Proceeds from sale of equipment held for rental	14.9	13.0	16.3	38.8
Acquisition of equity securities	(1.2)	(17.4)	(41.0)	(2.9)
Other investing activities	0.8	3.4	4.5	16.7
Net cash used in investing activities	(28.7)	(300.4)	(245.6)	(77.6)
Financing activities:
Proceeds from debt (original maturities greater than three months)		10.4		303.9
Repayments of debt (original maturities greater than three months)		(225.0)	(5.2)	(300.0)
Debt issuance costs		(2.5)		(9.6)
Repurchases of Common Stock	(150.0)	(155.0)	(107.8)	(40.8)
Dividends paid	(24.9)	(97.3)	(90.4)	(81.8)
Proceeds from exercise of stock options	2.7	3.1	42.8	26.1
Acquisition of Common Stock for taxes on stock-based compensation	(12.0)	(8.3)	(14.3)	(10.7)
Other financing activities	(2.1)	(10.4)	(5.5)	(2.6)
Net cash used in financing activities	(186.3)	(485.0)	(180.4)	(115.5)
Effect of exchange rate changes on cash and cash equivalents	(2.0)	(5.7)	(2.7)	0.3
Increase (decrease) in cash and cash equivalents	(380.1)	(189.8)	792.9	134.5
Cash and cash equivalents at beginning of period	1,375.8	995.7	582.9	448.4
Cash and cash equivalents at end of period	995.7	805.9	1,375.8	582.9
Supplemental disclosures:
Cash paid for interest	12.2	49.6	45.2	55.9
Cash paid for income taxes	2.7	257.3	153.9	157.2
Cash received from income tax refunds	7.5	250.8	26.6
Cash paid for operating lease liabilities	12.2	49.8	51.4	55.8
Operating right-of-use assets obtained	$ 20.6	$ 56.0	$ 92.5	$ 23.3