Self-Insurance - Components of Self-Insurance (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Insurance [Abstract]
Current liability — workers' compensation and general liability	$ 197	$ 703
Current liability — medical and dental	764	821
Non-current liability	890	382
Total liability	1,851	1,906
Restricted cash	$ 113	$ 113

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due after one year (or beyond the operating cycle if longer), including liabilities for compensation costs, fringe benefits other than pension and postretirement obligations, rent, contractual rights and obligations, and statutory obligations.

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Amount of liabilities classified as other.

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Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer.

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Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. 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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Carrying value as of the balance sheet date of obligations and payables pertaining to claims incurred of a workers compensation nature. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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