Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Retainage receivable estimated by management to be collected beyond one year, percentage	43.00%
Capitalized contract costs amortized and recognized as expense	$ 12.6	$ 11.8
Retainage payable estimated by management to be remitted beyond one year, percentage	37.00%
Liability revenue recognized from contract with customer	$ 317.8	$ 306.9