Acquisitions, Dispositions, and Deconsolidations - Schedule of Purchase Price Allocations, Construction Segment (Details) - USD ($)	May 27, 2021	Jun. 30, 2021	Dec. 31, 2020
Purchase Consideration at Fair Value
Goodwill		$ 121,100,000	$ 111,000,000.0
Banker Steel Acquisition
Purchase Consideration at Fair Value
Bankers Steel debt - assumed	$ 6,300,000
Cash	25,000,000.0
Gross consideration	145,000,000.0
Less: Transaction costs	400,000
Less: Bankers debt - assumed	6,300,000
Less: R&W premium paid by seller	500,000
Net consideration	137,800,000
Cash and cash equivalents	9,300,000
Accounts receivable, net	111,300,000
Costs recognized in earnings in excess of billings on uncompleted contracts	1,900,000
Assets held for sale	700,000
Other current assets	7,300,000
Property, plant, and equipment, net	62,600,000
Other assets	40,200,000
Intangibles, net	58,500,000
Goodwill	10,300,000
Total assets to be acquired	302,100,000
Accounts Payable	39,100,000
Billings in excess of costs and recognized earnings on uncompleted contracts	55,000,000.0
Other current liabilities	29,600,000
Other liabilities	34,200,000
Long-term debt, less current portion	6,400,000
Total liabilities to be assumed	164,300,000
Total net assets acquired	137,800,000
Banker Steel Acquisition | Sellers' Notes
Purchase Consideration at Fair Value
Face amount	49,600,000
Banker Steel Acquisition | Revolving Credit Facility
Purchase Consideration at Fair Value
Face amount	64,100,000
Banker Steel Acquisition | Term Loan
Purchase Consideration at Fair Value
Face amount	$ 110,000,000.0