Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net income (loss)	$ (80.9)	$ (10.6)	$ 98.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	391.1	277.8	201.5
Stock-based compensation	17.2	16.4	16.5
Certain interest expense and other financing costs	11.5	12.1	17.3
Beneficial lease amortization	0.0	2.3	0.0
Loss on debt extinguishment	14.7	0.0	1.2
Gain on sale of fixed assets and other	(3.5)	(3.8)	(1.3)
Deferred income taxes	(25.6)	(2.6)	(30.1)
338(h)(10) election refund	(5.1)	0.0	0.0
Changes in operating assets and liabilities:
Accounts receivable	78.4	(18.5)	(45.0)
Inventories	73.4	(82.8)	(65.1)
Prepaid expenses and other current assets	(73.6)	(70.8)	57.6
Accounts payable and accrued expenses	72.2	92.1	287.4
Other assets and liabilities	9.5	1.1	0.8
Net cash provided by (used in) operating activities	479.3	212.7	539.4
Investing Activities
Purchases of property and equipment	(48.5)	(57.0)	(46.0)
Acquisition of businesses, net	5.1	(164.0)	(2,740.5)
Proceeds from the sale of assets	4.4	9.3	2.1
Net cash provided by (used in) investing activities	(39.0)	(211.7)	(2,784.4)
Financing Activities
Borrowings under revolving lines of credit	2,038.0	2,100.1	2,807.7
Payments under revolving lines of credit	(1,870.0)	(2,114.0)	(2,707.7)
Borrowings under term loan	0.0	0.0	970.0
Payments under term loan	(9.7)	(9.7)	(445.8)
Borrowings under senior notes	300.0	0.0	1,300.0
Payment under senior notes	(309.6)	0.0	0.0
Payment of debt issuance costs	(4.3)	(0.8)	(65.8)
Payments under equipment financing facilities and finance leases	(8.6)	(10.0)	(11.6)
Proceeds from issuance of convertible preferred stock	0.0	0.0	400.0
Payment of stock issuance costs	0.0	0.0	(1.3)
Payment of dividends on Preferred Stock	(24.0)	(24.0)	(13.0)
Proceeds from issuance of common stock related to equity awards	3.3	3.3	7.5
Payment of taxes related to net share settlement of equity awards	(2.9)	(3.7)	(4.0)
Net cash provided by (used in) financing activities	112.2	(58.8)	2,236.0
Effect of exchange rate changes on cash and cash equivalents	(0.2)	0.2	0.6
Net increase (decrease) in cash and cash equivalents	552.3	(57.6)	(8.4)
Cash and cash equivalents, beginning of period	72.3	129.9	138.3
Cash and cash equivalents, end of period	624.6	72.3	129.9
Cash paid during the period for:
Interest	130.3	146.4	111.3
Income taxes paid (received), net of refunds	$ (5.4)	$ (8.5)	$ 35.1