XML 79 R63.htm IDEA: XBRL DOCUMENT v3.20.4
Inventories (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Inventory Disclosure [Abstract]    
Raw materials and construction materials $ 42,240 $ 31,365
Work in process 11,098 9,081
Inventories $ 53,338 $ 40,446