XML 44 R31.htm IDEA: XBRL DOCUMENT v3.10.0.1
Business (Merger and business combination) (Details)
$ / shares in Units, shares in Millions, $ in Millions
Sep. 04, 2018
$ / shares
shares
Mar. 28, 2018
USD ($)
shares
Jan. 30, 2018
item
$ / shares
shares
Sep. 30, 2018
USD ($)
item
Dec. 31, 2017
USD ($)
Business Combination          
Number of mobile offshore drilling units       41  
Aggregate principal amount outstanding | $       $ 9,434 $ 7,484
0.50% Exchangeable Bonds due January 2023          
Business Combination          
Aggregate principal amount outstanding | $   $ 863   $ 863  
Debt instrument interest rate stated percentage       0.50%  
Ocean Rig          
Business Combination          
Number of mobile offshore drilling units       11  
Ultra-deepwater floaters          
Business Combination          
Number of mobile offshore drilling units       23  
Ultra-deepwater floaters | Ocean Rig          
Business Combination          
Number of mobile offshore drilling units       9  
Harsh environment floaters          
Business Combination          
Number of mobile offshore drilling units       12  
Harsh environment floaters | Ocean Rig          
Business Combination          
Number of mobile offshore drilling units       2  
Midwater floaters          
Business Combination          
Number of mobile offshore drilling units       4  
Ocean Rig          
Business Combination          
Ratio of shares to be issued for consideration 1.6128        
Business combination consideration (per share) | $ / shares $ 12.75        
Newly issued shares (in shares) | shares 147.7        
Songa          
Business Combination          
Ownership interest (as a percent)     97.70%    
Business combination consideration (per share) | $ / shares     $ 10.99    
Number of mobile offshore drilling units     7    
Newly issued shares (in shares) | shares   68.0 66.9    
Songa | 0.50% Exchangeable Bonds due January 2023          
Business Combination          
Aggregate principal amount outstanding | $   $ 863      
Debt instrument interest rate stated percentage   0.50%      
Songa | Harsh environment floaters          
Business Combination          
Number of mobile offshore drilling units     5    
Songa | Midwater floaters          
Business Combination          
Number of mobile offshore drilling units     2