Contract Assets and Liabilities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Retainage receivable estimated by management to be collected beyond one year, percentage	31.00%
Costs and estimated earnings in excess of billings estimated to be collected	$ 795.2
Capitalized contract costs were amortized and recognized as expense	$ 47.3	$ 46.7	$ 33.8
Retainage payable estimated by management to be remitted beyond one year, percentage	24.00%
Revenue recognized	$ 638.7	$ 690.7	$ 479.6