Goodwill and Other Intangible Assets - Gross carrying amount and accumulated amortization of the company's intangible assets other than goodwill (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Intangible asset balances by major asset class
Intangible assets, gross (excluding goodwill)	$ 156.9	$ 160.5
Finite-lived intangible assets, amortization amount	(38.2)	(38.9)
Intangible assets, book value	118.7	121.6
Indefinite-lived Intangible Assets
Intangible asset balances by major asset class
Intangible assets, gross (excluding goodwill)	116.8	119.6
Intangible assets, book value	116.8	119.6
Indefinite-lived Intangible Assets | Distribution Network
Intangible asset balances by major asset class
Finite-lived intangible assets, carrying amount	19.2	19.6
Finite-lived intangible assets, book value	19.2	19.6
Indefinite-lived Intangible Assets | Trademarks and Tradenames
Intangible asset balances by major asset class
Indefinite-lived intangible assets, book value	97.6	100.0
Finite-Lived Intangible Assets
Intangible asset balances by major asset class
Intangible assets, gross (excluding goodwill)	40.1	40.9
Finite-lived intangible assets, amortization amount	(38.2)	(38.9)
Intangible assets, book value	1.9	2.0
Finite-Lived Intangible Assets | Customer Relationships
Intangible asset balances by major asset class
Finite-lived intangible assets, carrying amount	9.8	9.9
Finite-lived intangible assets, amortization amount	(8.6)	(8.6)
Finite-lived intangible assets, book value	1.2	1.3
Finite-Lived Intangible Assets | Patents
Intangible asset balances by major asset class
Finite-lived intangible assets, carrying amount	30.3	31.0
Finite-lived intangible assets, amortization amount	(29.6)	(30.3)
Finite-lived intangible assets, book value	$ 0.7	$ 0.7