Other Assets - Other Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Other noncurrent assets:
Note receivables - OPA	$ 43.5	$ 38.7
Restricted cash and cash equivalents	36.5	41.9
Land held for development	28.0	36.0
Operating lease right-of-use assets	20.3	19.9
IBNR receivables	19.2	34.4
Pension asset	7.8	9.0
Marketable securities	3.6	3.3
Other	16.2	16.8
Total	$ 175.1	$ 200.0