Assets and Liabilities Held for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets held for sale:
Total current assets	$ 17,479	$ 7,792
Current liabilities
Total current liabilities	10,762	5,260
Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale:
Cash and cash equivalents	0	0
Receivables, net	4,237	1,309
Retainage	234	15
Contract assets	2,920	1,777
Inventories	3,971	2,123
Prepaid expenses and other current assets	587	300
Total current assets	11,949	5,524
Property, plant & equipment, less accumulated depreciation	3,395	2,268
Operating lease assets	2,135	0
Total assets held for sale	17,479	7,792
Current liabilities
Accounts payable	1,801	1,331
Accrued expenses	5,516	3,891
Contract liabilities	1,100	38
Current maturities of long-term debt	895	0
Total current liabilities	9,312	5,260
Total current liabilities	1,219	0
Other non-current liabilities	231	0
Total liabilities held for sale	$ 10,762	$ 5,260