Contract Assets And Liabilities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Contract Assets and Liabilities [Abstract]
Retainage receivable estimated by management to be collected beyond one year, percentage	39.00%
Contracts Receivable, Claims and Uncertain Amounts, Expected to be Collected after Next Twelve Months	$ 572.1
Capitalized contract costs were amortized and recognized as expense	$ 33.8	$ 16.3
Retainage payable estimated by management to be remitted beyond one year, percentage	28.00%
Contract with Customer, Liability, Revenue Recognized	$ 479.6	$ 382.7