Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net Earnings Including Redeemable Noncontrolling Interest	$ 32.9	$ 31.8
Hedging adjustments:
Net gain on derivatives	0.0	0.6
Reclassifications to net earnings	0.5	0.0
Foreign currency translation adjustments:
Unrealized foreign currency translation adjustments	0.9	0.5
Total Other Comprehensive Income Including Redeemable Noncontrolling Interest	1.4	1.1
Less: Comprehensive income attributable to redeemable noncontrolling interest	26.1	26.3
Total Comprehensive Income Available to Class A Common Stockholders	$ 8.2	$ 6.6