Business Dispositions - (Schedule of Major Classes of Assets and Liabilities of Businesses Reported as Discontinued Operations) (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Assets:
Accounts receivable—net	$ 13,943
Contract revenues in excess of billings	9,971
Other current assets	865
Assets held for sale	24,779
Property and equipment—net	6,612
Goodwill	7,000
Other intangible assets—net	372
Other assets	1,699
Reserve for loss on disposal	(14,110)
Assets held for sale—noncurrent	1,573
Liabilities:
Accounts payable	8,343
Accrued expenses	4,380
Other current liabilities	1,217
Liabilities held for sale	13,940
Other liabilities	146
Liabilities held for sale—noncurrent	$ 146