Other Assets - Other Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Other noncurrent assets:
Note receivables - OPA	$ 46.5	$ 49.3
Restricted cash and cash equivalents	30.9	37.2
Land held for development	29.6	29.7
Operating lease right-of-use assets	21.3	21.5
IBNR receivables	15.4	16.8
Pension asset	9.8	9.3
Marketable securities	1.6	1.2
Other	24.8	24.3
Total	$ 178.3	$ 188.1