Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Retainage receivable estimated by management to be collected beyond one year, percentage	58.00%		58.00%
Costs and estimated earnings in excess of billings	$ 630.8		$ 630.8
Capitalized contract costs amortized and recognized as expense	$ 14.7	$ 13.7	$ 34.5	$ 45.3
Retainage payable estimated by management to be remitted beyond one year, percentage	46.00%		46.00%
Liability revenue recognized from contract with customer	$ 439.8	$ 447.4	$ 663.6	$ 487.1