Other noncurrent assets - Other assets (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Other noncurrent assets:
Restricted cash and cash equivalents	$ 32.3		$ 32.4
Note receivables - OPA	66.8		69.1
Operating lease right-of-use assets	22.1		22.7
Land held for development	16.2		19.4
IBNR receivables	13.4		13.4
Pension asset	8.6		8.1
Other	21.5		16.7
Total	180.9		$ 181.8
City of Henderson Redevelopment Agency | OPA | OtherIncome
Other noncurrent assets:
Infrastructure reimbursement	$ 0.0	$ 0.0