Annual report pursuant to Section 13 and 15(d)

Debt (Details)

v3.8.0.1
Debt (Details)
$ in Thousands, shares in Millions
1 Months Ended 8 Months Ended 12 Months Ended
Dec. 31, 2017
USD ($)
shares
Aug. 31, 2017
USD ($)
Oct. 31, 2014
USD ($)
Oct. 30, 2014
USD ($)
item
Oct. 31, 2015
USD ($)
Nov. 30, 2014
USD ($)
Aug. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2016
USD ($)
Mar. 21, 2016
USD ($)
Mar. 27, 2015
USD ($)
Debt disclosures                        
Current portion of debt                   $ 400,000    
Total Long-term and Short-term debt $ 500,000             $ 500,000   600,000    
Long-term Debt $ 497,370             497,370   198,512    
Repayments of debt               600,000 $ 40,000      
Margin Loan Agreements | Charter                        
Debt disclosures                        
Number of common shares pledged as collateral | shares 6.8                      
Value of pledged collateral $ 2,300,000             2,300,000        
Margin Loan Agreements | LIBOR                        
Debt disclosures                        
Interest rate basis             three-month LIBOR          
2014 Margin Loan Agreement                        
Debt disclosures                        
Maximum borrowing capacity                   400,000    
Proceeds From Issuance Of Secured Debt         $ 28,000 $ 52,000            
2014 Margin Loan Agreement | Three-month LIBOR                        
Debt disclosures                        
Basis spread on variable rate             1.55%          
2014 Margin Loan Agreement | Term loan                        
Debt disclosures                        
Unused commitment fee percentage             0.25%          
Revolving Credit Facility                        
Debt disclosures                        
Maximum borrowing capacity                       $ 234,000
BroadbandSPV | 2014 Margin Loan Agreement                        
Debt disclosures                        
Current portion of debt                   400,000    
Number of debt agreements | item       2                
Maximum borrowing capacity       $ 400,000                
Remaining borrowing capacity     $ 80,000                  
Proceeds From Issuance Of Secured Debt     $ 320,000                  
Repayments of debt   $ 400,000                    
Cheetah 5 | 2016 Margin Loan Agreement                        
Debt disclosures                        
Long-term Debt, Gross                   200,000    
Maximum borrowing capacity                     $ 300,000  
Repayments of debt   200,000                    
Cheetah 5 | 2016 Margin Loan Agreement | LIBOR                        
Debt disclosures                        
Interest rate basis             LIBOR          
Basis spread on variable rate             2.10%          
Cheetah 5 | 2016 Margin Loan Agreement | Term loan                        
Debt disclosures                        
Maximum borrowing capacity                     200,000  
Line of Credit, Current                   200,000    
Cheetah 5 | 2016 Margin Loan Agreement | Draw loan                        
Debt disclosures                        
Maximum borrowing capacity                     $ 100,000  
Unused commitment fee percentage             0.50%          
Remaining borrowing capacity                   $ 100,000    
SPV | 2017 Margin Loan Agreement                        
Debt disclosures                        
Long-term Debt, Gross 500,000             500,000        
Maximum borrowing capacity   1,000,000         $ 1,000,000          
Additional allowed borrowing capacity   $ 1,000,000         $ 1,000,000          
Remaining borrowing capacity $ 500,000             $ 500,000        
Basis spread on variable rate   0.50%                    
Debt Instrument, Interest Rate, Effective Percentage 3.19%             3.19%        
SPV | 2017 Margin Loan Agreement | LIBOR                        
Debt disclosures                        
Interest rate basis   LIBOR                    
Basis spread on variable rate   1.00%                    
SPV | 2017 Margin Loan Agreement | Three-month LIBOR                        
Debt disclosures                        
Interest rate basis   three-month LIBOR                    
Basis spread on variable rate   1.50%                    
SPV | 2017 Margin Loan Agreement | Federal Funds Rate                        
Debt disclosures                        
Basis spread on variable rate   0.50%