Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Earnings Including Redeemable Noncontrolling Interest	$ 31.8	$ 25.1
Hedging adjustments:
Unrealized net gain on derivatives	0.6	0.0
Foreign currency translation adjustments:
Unrealized foreign currency translation adjustments	0.5	(0.3)
Total Other Comprehensive Income (Loss)	1.1	(0.3)
Less: Comprehensive income attributable to redeemable noncontrolling interest	26.3	24.8
Total Comprehensive Income Available to Class A Common Stockholders	$ 6.6	$ 0.0