Business Combination - Schedule of Purchase Price and Allocation of Purchase Price (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Oct. 04, 2016	Oct. 04, 2016	Dec. 31, 2017	Dec. 31, 2016
Purchase price:
Purchase price			$ 0	$ 5,211
EBGL Acquisition
Purchase price:
Cash paid at closing		$ 2,960
Fair value of deferred payments owing to EBGL Sellers		941
Fair value of contingent earn-out liability		943
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable		149
Purchase price adjustment – paid in January 2017		218
Purchase price		$ 5,211
Number of shares issued in business combination (in shares)		100,000
Business acquisition, share price (USD per share)	$ 1.49	$ 1.49
Assets acquired:
Inventories	$ 898	$ 898
Costs and estimated profit in excess of billings	93	93
Prepaid expenses	3	3
Equipment	289	289
Goodwill	3,020	3,020
Customer relationships	677	677
Tradenames	104	104
Purchased backlog	300	300
Total assets acquired	5,384	5,384
Liabilities assumed:
Billings in excess of costs and estimated profits	(31)	(31)
Accrued compensation	(40)	(40)
Accrued other liabilities	(102)	(102)
Total liabilities assumed	173	173
Net assets acquired	$ 5,211	$ 5,211
Customer relationships | EBGL Acquisition
Liabilities assumed:
Amortization period	6 years
Purchased backlog | EBGL Acquisition
Liabilities assumed:
Amortization period	1 year