Financial Instruments, Derivatives and Hedging Activities - Additional information - FV hedges (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Additional information pertaining to fair value hedges
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Liabilities	$ (2)	$ 1
Fair Value Hedging | Long-term debt
Additional information pertaining to fair value hedges
Carrying Amount of the Hedged Liabilities	(202)	(199)
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Liabilities	$ (2)	$ 1