Annual report pursuant to Section 13 and 15(d)

Equity Method Investments - Narrative (Details)

v3.19.1
Equity Method Investments - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Jul. 27, 2016
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]        
Difference between carrying value of equity method investment and equity   $ 60.6   $ 60.6
Finite lived intangible asset, weighted average useful life 14 years 10 months 24 days      
Wireless Maritime Services        
Schedule of Equity Method Investments [Line Items]        
Equity method investment, ownership percentage 49.00% 49.00%   49.00%
Impairment loss   $ 51.0 $ 16.7 $ 51.0
Santander        
Schedule of Equity Method Investments [Line Items]        
Equity method investment, ownership percentage 49.00% 49.00%   49.00%