Other assets - Other assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Other noncurrent assets:
Restricted cash and cash equivalents	$ 32.3		$ 32.4
Note receivables - OPA	65.7		69.1
Operating lease right-of-use assets	21.8		22.7
Land held for development	16.9		19.4
IBNR receivables	13.3		13.4
Pension asset	8.4		8.1
Other	17.5		16.7
Total	175.9		$ 181.8
City of Henderson Redevelopment Agency | OPA | OtherIncome
Other noncurrent assets:
Infrastructure reimbursement	$ 0.0	$ 0.0