General form of registration statement for all companies including face-amount certificate companies

Property and Equipment - net - Summary of Property and Equipment - net (Detail)

v3.21.2
Property and Equipment - net - Summary of Property and Equipment - net (Detail) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross $ 47,111 $ 38,203 $ 21,221
Less: accumulated depreciation (25,408) (17,351) (9,543)
Less: held for sale, net   0 (710)
Property and equipment - net 21,703 20,852 10,968
Satellites [Member]      
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 41,380 32,340 14,288
Computer Equipment and Software [Member]      
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 1,567 1,315 1,477
Office Furniture and Fixtures [Member]      
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 870 1,388 2,052
Other Equipment [Member]      
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 653 434 718
Site Equipment [Member]      
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 1,377 1,311 1,271
Ground Station Equipment [Member]      
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross $ 1,264 $ 1,415 $ 1,415