Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v3.10.0.1
Debt (Details)
$ in Thousands
6 Months Ended
Aug. 31, 2017
USD ($)
Mar. 21, 2016
loan
Oct. 30, 2014
loan
Jun. 30, 2018
USD ($)
shares
Apr. 04, 2018
USD ($)
Dec. 31, 2017
USD ($)
Debt disclosures            
Long-term Debt       $ 523,159   $ 497,370
Margin Loan Agreements | Charter            
Debt disclosures            
Number of common shares pledged as collateral | shares       6,800,000    
Value of pledged collateral       $ 2,000,000    
2017 Margin Loan Agreement            
Debt disclosures            
Debt Instrument, Interest Rate, Effective Percentage       3.80%    
SPV | 2017 Margin Loan Agreement            
Debt disclosures            
Long-term Debt, Face Amount         $ 25,000  
Long-term Debt, Gross       $ 525,000   $ 500,000
Maximum borrowing capacity $ 1,000,000          
Additional allowed borrowing capacity $ 1,000,000          
Remaining borrowing capacity       $ 475,000    
Basis spread on variable rate 0.50%          
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%          
BroadbandSPV            
Debt disclosures            
Number of debt agreements | loan     2      
Cheetah 5            
Debt disclosures            
Number of debt agreements | loan   2