Basis Of Presentation Basis of Presentation (Tables)

6 Months Ended

Jun. 30, 2018

Net cumulative catch-up adjustments [Abstract]

Schedule of Change in Accounting Estimate [Table Text Block]

Unbilled receivables (contract assets) arise when the Company recognizes revenue for amounts which cannot yet be billed under terms of the contract with the customer. Advances and progress billings (contract liabilities) arise when the Company receives payments from customers in advance of recognizing revenue. The amount of Unbilled receivables or Advances and progress billings is determined for each contract.