Business Dispositions - (Schedule of Major Classes of Assets and Liabilities of Businesses Reported as Discontinued Operations ) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Accounts receivable—net	$ 13,943	$ 23,593
Contract revenues in excess of billings	9,971	12,881
Other current assets	865	1,943
Assets held for sale	24,779	38,417
Property and equipment—net	6,612	10,369
Goodwill	7,000	7,000
Other intangible assets—net	372	907
Other assets	1,699	2,825
Reserve for loss on disposal	(14,110)
Assets held for sale—noncurrent	1,573	21,101
Liabilities:
Accounts payable	8,343	22,505
Accrued expenses	4,380	4,292
Other current liabilities	1,217	2,576
Liabilities held for sale	13,940	29,373
Other liabilities	146	773
Liabilities held for sale—noncurrent	$ 146	$ 773