Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net service revenues	$ 2,553.6	$ 2,346.0	$ 2,404.6
Cost of services provided	1,902.8	1,750.7	1,766.4
Gross profit	650.8	595.3	638.2
Selling, general and administrative expense	508.0	527.4	452.2
Amortization expense	52.3	55.8	56.3
Income from operations	90.5	12.1	129.7
Other income	2.7	1.3	0.0
Interest expense	42.3	64.6	72.5
Income (loss) income before income taxes	50.9	(51.2)	57.2
Income tax expense (benefit)	4.6	(9.6)	12.8
Net income (loss)	$ 46.3	$ (41.6)	$ 44.4
Income (loss) income per share:
Basic and Diluted	$ 0.44	$ (0.40)	$ 0.43