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

Equity Method Investments - Additional Information (Detail)

v3.21.2
Equity Method Investments - Additional Information (Detail)
shares in Millions, $ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
shares
Jun. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Satellites
Schedule of Equity Method Investments [Line Items]          
Difference between carrying value of equity method investments and undelying equity in the net assets of the investees $ 1.6   $ 0.5 $ 0.0  
Revenue from related parties 14.8        
LeoStella [Member]          
Schedule of Equity Method Investments [Line Items]          
Payments to acquire equity method investments         $ 7.0
Remittance of capital investments $ 11.2 $ 6.2      
LeoStella [Member] | Blacksky Technology [Member]          
Schedule of Equity Method Investments [Line Items]          
Equity method investment ownership percentage 50.00% 50.00% 50.00% 50.00% 50.00%
LeoStella [Member] | Satellite Purchase Contract [Member] | Commitments To Purchase Satellites [Member]          
Schedule of Equity Method Investments [Line Items]          
Long term prchase commitement minimum quantity required | Satellites         20
Long term purchase commitement amount         $ 79.0
Purchase commitment amount receivable towards discount         $ 8.8
Discount received amount     $ 5.1    
Minimum monthly payment agreed     1.0    
Gross payments made towards capital work in progress     8.2 $ 23.3  
LeoStella [Member] | Satellite Purchase Contract [Member] | Commitments To Purchase Satellites [Member] | Intelsat Facility [Member]          
Schedule of Equity Method Investments [Line Items]          
Minimum monthly payment agreed     $ 2.0    
LeoStella [Member] | Thales [Member]          
Schedule of Equity Method Investments [Line Items]          
Equity method investment ownership percentage 50.00% 50.00% 50.00% 50.00% 50.00%
X-Bow [Member] | Stock Subscription And Technology Transfer Agreement [Member]          
Schedule of Equity Method Investments [Line Items]          
Equity method investment ownership percentage 20.60%   20.60%    
Investment owned number of shares | shares 13.5   13.5    
LeoStella And X-Bow [Member]          
Schedule of Equity Method Investments [Line Items]          
Inventory $ 39.7   $ 47.3 $ 31.9  
Notes payable to related parties $ 46.1   $ 51.4 $ 56.0