Other Assets - Other Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Other noncurrent assets:
Restricted cash and cash equivalents	$ 43.9	$ 41.9
Note receivables - OPA	36.0	38.7
Land held for development	31.0	36.0
IBNR receivables	29.9	34.4
Operating lease right-of-use assets	21.5	19.9
Pension asset	9.5	9.0
Marketable securities	2.9	3.3
Other	16.0	16.8
Total	$ 190.7	$ 200.0