Goodwill (Tables)

12 Months Ended

Sep. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Carrying Amount of Goodwill

	Post Consumer Brands		Weetabix		Foodservice		Refrigerated Retail		Total
Balance, September 30, 2021
Goodwill (gross)	$	2,067.1	$	929.4	$	1,355.0	$	807.9	$	5,159.4
Accumulated impairment losses	(609.1)		—		—		(48.7)		(657.8)
Goodwill (net)	$	1,458.0	$	929.4	$	1,355.0	$	759.2	$	4,501.6
Goodwill from acquisitions (a)	—		13.9		0.3		—		14.2
Sale of business (b)	—		—		—		(4.2)		(4.2)
Currency translation adjustment	(0.3)		(161.7)		—		—		(162.0)
Balance, September 30, 2022
Goodwill (gross)	$	2,066.8	$	781.6	$	1,355.3	$	803.7	$	5,007.4
Accumulated impairment losses	(609.1)		—		—		(48.7)		(657.8)
Goodwill (net)	$	1,457.7	$	781.6	$	1,355.3	$	755.0	$	4,349.6
Goodwill from acquisition	194.2		—		—		—		194.2
Impairment loss	—		—		—		(42.2)		(42.2)
Currency translation adjustment	0.1		72.7		—		—		72.8
Balance, September 30, 2023
Goodwill (gross)	$	2,261.1	$	854.3	$	1,355.3	$	803.7	$	5,274.4
Accumulated impairment losses	(609.1)		—		—		(90.9)		(700.0)
Goodwill (net)	$	1,652.0	$	854.3	$	1,355.3	$	712.8	$	4,574.4

(a)In fiscal 2022, the Company recorded $13.9 of goodwill related to the Lacka Foods acquisition and also recorded a final measurement period adjustment of $0.3 related to the Almark acquisition. For additional information on the Company’s acquisitions, see Note 6.

(b)In December 2021, the Company completed the WEF Transaction. For additional information on the WEF Transaction, see Note 7.