Accounts Receivable, net - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable – net	$ 42,980	$ 41,774
Government
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable – net	10,277	11,000
Government | Billed
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable – net	11,225	11,608
Government | Advanced billings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable – net	948	608
Restaurant/Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable – net	$ 32,703	$ 30,774