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PHPC (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		8 Months Ended	9 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	May 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2021	Mar. 31, 2023	Sep. 30, 2022	Mar. 31, 2022
Schedule of Equity Method Investments
Investments held in trust	$ 0.0		$ 353.4	$ 0.0				$ 346.8
Initial public offering costs						$ 17.9
Deferred Offering Costs								10.7
Redeemable noncontrolling interest	0.0		312.5	0.0				$ 306.6
Maximum interest to pay dissolution expenses			$ 0.1
Gain on write-off of underwriting commissions	10.7			10.7
Return of subsidiary investments held in trust account				345.0	$ 0.0
PHPC Units
Schedule of Equity Method Investments
Common Unit, Issued			34.5
Share Price			$ 10.00
Redemption Price			10.24
PHPC Warrants
Schedule of Equity Method Investments
Class of Warrant or Right, Exercise Price of Warrants or Rights			11.50
PHPC Private Placement Units
Schedule of Equity Method Investments
Share Price			10.00
PHPC Forward Purchase Units
Schedule of Equity Method Investments
Share Price			$ 10.00
PHPC Forward Purchase Units \| Maximum
Schedule of Equity Method Investments
Common Unit, Authorized			10.0
PHPC Sponsor \| PHPC Private Placement Units
Schedule of Equity Method Investments
Common Unit, Issued			1.1
PHPC Sponsor \| PHPC Forward Purchase Units \| Maximum
Schedule of Equity Method Investments
Proceeds from Issuance of Forward Purchase Agreement						100.0
PHPC
Schedule of Equity Method Investments
Proceeds from initial public offering						345.0
PHPC \| Common Class A
Schedule of Equity Method Investments
Common Stock, Par or Stated Value Per Share			$ 0.0001
PHPC \| Series F Common Stock
Schedule of Equity Method Investments
Common Stock, Par or Stated Value Per Share			0.0001
PHPC \| Common Class B
Schedule of Equity Method Investments
Common Stock, Par or Stated Value Per Share			$ 0.0001
PHPC \| PHPC Units
Schedule of Equity Method Investments
Proceeds from initial public offering						345.0
PHPC \| PHPC Private Placement Units
Schedule of Equity Method Investments
Proceeds from Issuance of Private Placement						10.9
PHPC \| Post Holdings, Inc.
Schedule of Equity Method Investments
Noncontrolling Interest, Ownership Percentage by Parent			31.00%					31.00%
PHPC \| Public Shareholders
Schedule of Equity Method Investments
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			69.00%					69.00%
PHPC Sponsor \| Series F Common Stock
Schedule of Equity Method Investments
Common Stock, Shares, Outstanding			8.6
PHPC Sponsor \| PHPC Units
Schedule of Equity Method Investments
Common Unit, Issued			4.0
Return of subsidiary investments held in trust account			$ 40.9
Redeemable Noncontrolling Interest
Schedule of Equity Method Investments
Redeemable noncontrolling interest	0.0	$ 305.4		0.0	305.4	$ 305.0	$ 310.6	$ 306.6	$ 305.0
Net earnings attributable to redeemable noncontrolling interest	9.3	2.2		12.1	4.4
Noncontrolling interest, Redemption value adjustment	(1.9)	(0.4)		(5.9)	(0.4)
PHPC deemed dividend	7.4	1.8		6.2	4.0
Redemption of PHPC Series A Common Stock	$ (312.5)	$ 0.0		$ (312.5)	$ 0.0