Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for doubtful accounts	$ (4,123)	$ (2,989)
Total	230,864	238,102
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	143,471	144,616
U.S. Government contracts | Billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	17,244	20,289
U.S. Government contracts | Costs and accrued profit – not billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	1,478	4,248
Commercial and other government contracts | Billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	50,560	68,066
Commercial and other government contracts | Costs and accrued profit – not billed | Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	22,234	$ 3,872
K-MAX® program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables and accrued profit, included in Other Assets	$ 3,700