Other Assets - Other Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Other noncurrent assets:
Restricted cash and cash equivalents	$ 31.2	$ 37.2
Note receivables - OPA	47.9	49.3
Operating lease right-of-use assets	21.0	21.5
Land held for development	19.9	29.7
IBNR receivables	13.5	16.8
Pension asset	9.0	9.3
Other	17.4	24.3
Total	$ 159.9	$ 188.1