Other Assets - Other Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Other noncurrent assets:
Restricted cash and cash equivalents	$ 36.8	$ 41.9
Note receivables - OPA	36.6	38.7
IBNR receivables	30.7	34.4
Land held for development	27.2	36.0
Operating lease right-of-use assets	19.3	19.9
Pension asset	8.4	9.0
Marketable securities	3.5	3.3
Other	19.1	16.8
Total	181.6	$ 200.0
Noncurrent restricted cash reclassified	$ 7.3