XML 29 R49.htm IDEA: XBRL DOCUMENT v3.19.3
Revenue recognition - Changes in deferred revenue from contracts with customers (Details)
$ in Thousands
9 Months Ended
Sep. 30, 2019
USD ($)
Changes in deferred revenue from contracts with customers  
Balance at beginning of period $ 5,957
606 adoption adjustment (86)
Deferral of revenue 2,650
Recognition of deferred revenue (3,255)
Balance at end of period $ 5,266