Consolidated Statements of Cash Flows - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2017	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income (loss)		$ (14.0)	$ 44.4	$ (15.1)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation		56.5	80.1	75.3
Amortization of intangible assets		92.9	56.3	104.9
Amortization of financing costs and original issue discount		7.7	3.7	10.4
Loss on debt extinguishment	[1]			25.1
Deferred taxes		(34.8)	(2.3)	(63.4)
Equity-based compensation	[2]	3.8	15.7	28.8
Hedge ineffectiveness and realized loss		7.8	7.0	9.8
Provision for doubtful accounts		0.1	2.4	0.9
Other non-cash activities, net		(1.3)	(2.7)	0.6
Change in operating assets and liabilities:
Accounts receivable		(24.2)	(12.8)	25.2
Unbilled and deferred revenue		(42.3)	(34.8)	2.6
Inventories		6.2	(2.4)	1.7
Other operating assets		3.7	17.1	(16.5)
Accounts payable and other operating liabilities		16.8	(2.0)	(9.9)
Net cash provided by operating activities		78.9	169.7	180.4
Cash flows from investing activities:
Purchase of property and equipment		(50.6)	(89.9)	(86.4)
Proceeds from sale of property and equipment		6.3	6.8	12.0
Business acquisitions, net of cash acquired		(53.8)	(64.0)	(104.4)
Other investing activities, net		0.6	1.6	(0.5)
Net cash used in investing activities		(97.5)	(145.5)	(179.3)
Cash flows from financing activities:
Repayments of capital lease obligations		(3.9)	(5.8)	(6.3)
Repayments of debt		(181.6)	(143.0)	(1,662.6)
Proceeds from term loan, net of financing costs				1,016.9
Proceeds from receivables financing agreement		150.0	120.0	115.0
Proceeds from revolving credit facility			10.0	60.0
Proceeds from issuance of common stock, net of share issuance costs		0.1		501.2
Repurchase of common stock and distributions		(1.2)	(1.2)	(2.9)
Other financing activities, net			(0.3)
Net cash (used in) provided by financing activities		(36.6)	(20.3)	21.3
Net change in cash and cash equivalents		(55.2)	3.9	22.4
Cash and cash equivalents, beginning of period		68.0	35.2	12.8
Cash and cash equivalents, end of period		12.8	39.1	35.2
Supplemental Cash Flow Information:
Cash paid for income taxes, net		4.2	1.9	16.2
Cash paid for interest		$ 65.7	$ 71.7	$ 84.3

[1] Represents losses on the extinguishment of debt.

[2] Represents equity-based compensation expense recognized for equity incentive plans outstanding, including $19.6 related to the IPO in the fiscal year ended September 30, 2018.