Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 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	$ 625.8		$ 625.8
Capitalized contract costs amortized and recognized as expense	$ 9.0	$ 19.0	$ 19.8	$ 31.6
Retainage payable estimated by management to be remitted beyond one year, percentage	42.00%		42.00%
Liability revenue recognized from contract with customer	$ 439.5	$ 387.5	$ 564.4	$ 425.5