Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Line Items]
Restricted cash	$ 200,000	$ 200,000
Depreciation of continuing and discontinued operations	1,500,000	1,700,000
Depreciation	1,500,000	1,400,000
Depreciation expense related to the discontinued businesses	$ 0	$ 300,000
Customer Concentration Risk \| Sales Revenue, Net \| One Major Customer
Accounting Policies [Line Items]
Concentration risk percentage	23.00%	19.00%
Customer Concentration Risk \| Accounts Receivable \| One Major Customer
Accounting Policies [Line Items]
Concentration risk percentage	18.00%	10.00%
Customer Concentration Risk \| Accounts Receivable \| Second Customer
Accounting Policies [Line Items]
Concentration risk percentage	11.00%
Building \| Minimum
Accounting Policies [Line Items]
Useful lives	10 years
Building \| Maximum
Accounting Policies [Line Items]
Useful lives	20 years
Machinery and equipment \| Minimum
Accounting Policies [Line Items]
Useful lives	5 years
Machinery and equipment \| Maximum
Accounting Policies [Line Items]
Useful lives	10 years
Discontinued Operations
Accounting Policies [Line Items]
Discontinued operations restricted cash, current		$ 9,400,000
Discontinued operations, restricted cash, noncurrent	$ 1,700,000	$ 1,700,000

[Line Items] for Schedule of Accounting Policies [Table]

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Depreciation and Depreciation and Amortization, Discontinued Operations

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Disposal Group, Including Discontinued Operation, Depreciation

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Disposal Group, Including Discontinued Operation, Restricted Cash and Cash Equivalents

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Disposal Group, Including Discontinued Operation, Restricted Cash and Cash Equivalents, Noncurrent

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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