Related Party Transactions (Construction Management Firm and CCI) (Narrative) (Details) - Immediate Family Member of Management [Member] - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Construction Management Firm Specializing in Steel Building Systems [Member]
Related Party Transaction [Line Items]
Advances outstanding, related party		$ 0.2	$ 0.1
CCI [Member] \| Equipment [Member]
Related Party Transaction [Line Items]
Payments, net of rebates, related party	$ 5.0	$ 0.3
Payables, related party	4.6		$ 4.2
Revenue, related party	0.1
Receivables, related party	$ 0.1

Amount for accounts payable to related parties.

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