XML 62 R46.htm IDEA: XBRL DOCUMENT v3.19.1
Revenues - Contract Assets and Liabilities (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
Movement in Contract Assets and Liabilities [Roll Forward]  
Unbilled revenue, beginning balance $ 824
Increase in unbilled revenue 140
Unbilled revenue, ending balance 964
Accrued customer advances, beginning balance 3,229
Accrued customer advances, ending balance 5,328
Increase in accrued customer advances $ 2,099