Product Sales Contracts - Schedule of Costs, Estimated Earnings and Billings Presented in the Accompanying Financial Statements (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Contractors [Abstract] | ||
| Costs and estimated earnings in excess of billings on uncompleted contracts | $ 31,956 | $ 65,311 |
| Billings on uncompleted contracts in excess of costs and estimated earnings | (42,116) | (37,908) |
| Total costs, estimated earnings (losses) and billings on uncompleted contracts | $ (10,160) | $ 27,403 |