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

Equity Method Investments - Summary of Balance Sheet Information for the Company's Equity Method Investments (Detail)

v3.21.2
Equity Method Investments - Summary of Balance Sheet Information for the Company's Equity Method Investments (Detail) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]      
Current assets $ 210,375 $ 18,237 $ 65,863
Total assets 323,672 119,915 163,364
Current liabilities 27,394 55,443 100,300
Total liabilities 170,875 152,728 181,659
LeoStella And X-Bow [Member]      
Schedule of Equity Method Investments [Line Items]      
Current assets 73,494 64,355 62,208
Non-current assets 6,305 7,468 11,319
Total assets 79,799 71,823 73,527
Current liabilities 59,139 57,040 24,222
Non-current liabilities 896 6,589 36,543
Total liabilities $ 60,035 $ 63,629 $ 60,765