v3.7.0.1
Derivative and Financial Instruments - FX Notional (Details 5)
£ in Millions, $ in Millions
Mar. 31, 2017
GBP (£)
Mar. 31, 2017
USD ($)
Dec. 31, 2016
GBP (£)
Dec. 31, 2016
USD ($)
Sell US Dollar Buy Other Currencies [Member]        
Trading Activity, Gains and Losses, Net [Line Items]        
Net notional position of foreign currency exchange derivatives | $ [1]   $ 212   $ 13
Buy U.S. dollar, sell other currencies [Member]        
Trading Activity, Gains and Losses, Net [Line Items]        
Net notional position of foreign currency exchange derivatives | $ [2]   $ 0   $ 25
Buy British pound, sell other currencies [Member]        
Trading Activity, Gains and Losses, Net [Line Items]        
Net notional position of foreign currency exchange derivatives | £ [3] £ 12   £ 1,069  
Sell British pound, buy Norwegian krone [Member]        
Trading Activity, Gains and Losses, Net [Line Items]        
Net notional position of foreign currency exchange derivatives | £ £ 0   £ 51  
[1]
*Primarily Canadian dollar and Norwegian krone.
[2]
**Primarily British pound.
[3]
***Primarily Euro and Canadian dollar.