Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Narrative (Details)

v3.20.1
Fair Value Measurements - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Jul. 27, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Equity method investments $ 83,135 $ 78,886 $ 83,135  
Wireless Maritime Services        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Equity method investment, ownership percentage   49.00%   49.00%
Impairment loss $ 51,000 $ 0 $ 51,000  
Equity method investments   $ 76,100