Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for doubtful accounts	$ (1,246)	$ (2,498)
Accounts Receivable, after Allowance for Credit Loss, Current	156,492	149,338
Contract changes, negotiated settlements and claims for unanticipated contract costs	900	900
Trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	13,794	11,380
U.S. Government contracts | Billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	15,136	38,173
U.S. Government contracts | Costs and accrued profit – not billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	894	780
Commercial and other government contracts | Billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	120,427	100,603
Commercial and other government contracts | Costs and accrued profit – not billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 7,487	$ 900