Discontinued Operations - Additional Information (Details)		12 Months Ended
	Sep. 01, 2016 USD ($) option	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contracts revenue		$ 91,694,000	$ 101,739,000
Cost of revenues		28,457,000	33,517,000
Globus facility agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Maximum borrowing capacity	$ 30,000,000		30,000,000
Globus facility agreement | Line of credit
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Line of credit, expiration period	5 years
Supply agreement [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contracts revenue		8,000,000	14,400,000
Cost of revenues		$ 7,500,000	$ 12,100,000
Discontinued operations, disposed of by sale | International Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Supply commitment term	3 years
Supply agreement, number of annual options to extend | option	2