XML 51 R41.htm IDEA: XBRL DOCUMENT v3.19.2
Revenues (Customer Liability) (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]      
Contract liability $ 12,574   $ 11,043
Revenue recognized $ 4,000 $ 3,700