Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)

v3.8.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)
$ in Thousands
3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2017
USD ($)
Sep. 30, 2017
USD ($)
Mar. 31, 2017
USD ($)
Sep. 30, 2016
USD ($)
Jun. 30, 2017
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Jul. 27, 2016
member
Dec. 31, 2015
USD ($)
Accounting Policies [Line Items]                    
Cash and cash equivalents   $ 58,037   $ 56,155   $ 58,037 $ 56,155 $ 50,686   $ 223,552
Restricted Cash                    
Restricted cash   1,021       1,021   17,992    
Release of restricted cash held in escrow           17,100        
Intangible Assets and Goodwill:                    
Impairment of goodwill   0   $ 0   78,000 $ 0      
Goodwill   248,693       $ 248,693   327,836    
Equity Method Investments                    
Board of directors members, voting | member                 2  
Board of directors members | member                 2  
New Accounting Pronouncements                    
Change in accounting principle [1]               0    
Buildings                    
Property, plant and equipment                    
Property, plant and equipment, useful life           30 years        
Connectivity equipment                    
Property, plant and equipment                    
Property, plant and equipment, useful life           5 years        
Minimum | Equipment                    
Property, plant and equipment                    
Property, plant and equipment, useful life           3 years        
Minimum | Connectivity equipment                    
Property, plant and equipment                    
Property, plant and equipment, useful life         7 years          
Maximum                    
Restricted Cash                    
Period secured by cash           3 years        
Maximum | Equipment                    
Property, plant and equipment                    
Property, plant and equipment, useful life           10 years        
Maximum | Connectivity equipment                    
Property, plant and equipment                    
Property, plant and equipment, useful life         15 years          
Maritime & Land Connectivity                    
Intangible Assets and Goodwill:                    
Impairment of goodwill     $ 78,000     $ 78,000   64,000    
Goodwill   67,130       67,130   146,380    
Media & Content                    
Intangible Assets and Goodwill:                    
Impairment of goodwill           0        
Goodwill   $ 83,526       83,526   83,419    
Wireless Maritime Services                    
Equity Method Investments                    
Ownership percentage                 49.00%  
Board of directors members, voting | member                 5  
Santander                    
Equity Method Investments                    
Ownership percentage                 49.00%  
Board of directors members, voting | member                 5  
AT&T | Wireless Maritime Services                    
Equity Method Investments                    
Ownership percentage                 51.00%  
Board of directors members, voting | member                 3  
Erzia | Santander                    
Equity Method Investments                    
Ownership percentage                 51.00%  
Board of directors members | member                 3  
Additional Paid-in Capital                    
New Accounting Pronouncements                    
Change in accounting principle [1]               $ 288    
Forecast | Minimum                    
Taxes, Miscellaneous [Abstract]                    
Impact of new tax legislation $ 5,000                  
Forecast | Maximum                    
Taxes, Miscellaneous [Abstract]                    
Impact of new tax legislation 8,000                  
Maritime Telecommunications Network                    
Restricted Cash                    
Release of restricted cash held in escrow           16,000        
Maritime Telecommunications Network | Former Stockholders of Maritime Telecommunications Network                    
Restricted Cash                    
Release of restricted cash held in escrow           15,500        
Maritime Telecommunications Network | Global Eagle Entertainment Inc.                    
Restricted Cash                    
Release of restricted cash held in escrow           600        
Letters of Credit                    
Restricted Cash                    
Release of restricted cash held in escrow           $ 1,100        
Subsequent Event                    
Accounting Policies [Line Items]                    
Cash and cash equivalents $ 50,800                  
[1] Cumulative-effect adjustment related to the adoption of ASU 2016-09, as defined in Note 2. Basis of Presentation and Summary of Significant Accounting Policies. See Note 2. Basis of Presentation and Summary of Significant Accounting Policies for additional details.