Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net earnings including redeemable noncontrolling interest	$ 14.2	$ 40.3	$ 64.6	$ 96.4
Hedging adjustments:
Net gain (loss) on derivatives, before tax	0.0	0.0	(10.4)	0.0
Reclassification adjustment from AOCI on derivatives, before tax	0.6	0.0	0.4	0.0
Foreign currency translation adjustments:
Foreign Currency Translation Adjustment, before Tax	0.4	0.3	0.6	(0.4)
Tax benefit (expense) on other comprehensive income (loss)
Net gain (loss) on derivatives, tax	(0.1)	0.0	0.7	0.0
Total other comprehensive income (loss)	0.9	0.3	(8.7)	(0.4)
Less: Comprehensive income attributable to redeemable noncontrolling interest	11.6	40.6	44.1	96.0
Total comprehensive income available to Class A common stockholders	$ 3.5	$ 0.0	$ 11.8	$ 0.0