Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net service revenues	$ 673.6	$ 608.1	$ 1,879.9	$ 1,737.9
Cost of services provided	494.6	451.7	1,409.2	1,306.2
Gross profit	179.0	156.4	470.7	431.7
Selling, general and administrative expense	123.1	131.8	374.4	389.0
Amortization expense	12.6	13.6	39.0	40.6
(Loss) income from operations	43.3	11.0	57.3	2.1
Other (expense) income	0.8	1.7	2.8	0.4
Interest expense	9.4	15.4	32.5	49.9
Income (loss) before income taxes	34.7	(2.7)	27.6	(47.4)
Income tax expense (benefit)	9.5	(0.3)	8.1	(11.9)
Net income (loss)	$ 25.2	$ (2.4)	$ 19.5	$ (35.5)
Income (loss) per share:
Basic income (loss) per share	$ 0.24	$ (0.02)	$ 0.19	$ (0.34)
Diluted income (loss) earnings per share	$ 0.24	$ (0.02)	$ 0.18	$ (0.34)