XML 99 R92.htm IDEA: XBRL DOCUMENT v3.19.2
Risk management and financial instruments - Derivative Narrative (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2019
Dec. 31, 2018
May 11, 2018
Apr. 26, 2017
Derivative [Line Items]        
Convertible bond issued by Archer $ 244 $ 261    
LIBOR        
Derivative [Line Items]        
Basis spread on variable rate (as a percent) 2.33%      
Interest rate cap        
Derivative [Line Items]        
Impact that would be mitigated (as a percent) 46.00%      
Interest rate cap | Not designated as a hedge        
Derivative [Line Items]        
Derivative asset purchased     $ 68  
Interest rate cap | LIBOR        
Derivative [Line Items]        
Capped rate 2.87%      
Hypothetical increase in LIBOR rate (as a percent) 1.00%      
Interest rate cap | LIBOR | Not designated as a hedge        
Derivative [Line Items]        
Capped rate     2.87%  
Archer | Convertible bond        
Derivative [Line Items]        
Convertible bond issued by Archer       $ 45