Derivatives - Cash Flow Hedges - Gain (Loss) in OCI or Reclassified from AOCI (Details) - Cash flow hedge - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivatives in Cash Flow Hedging Relationships
Pretax Gain (Loss) Recognized in Other Comprehensive Income on Derivative	$ 44	$ (72)	$ 84	$ (10)
Foreign currency forward/option contracts
Derivatives in Cash Flow Hedging Relationships
Pretax Gain (Loss) Recognized in Other Comprehensive Income on Derivative	44	(72)	84	(8)
Interest rate contracts
Derivatives in Cash Flow Hedging Relationships
Pretax Gain (Loss) Recognized in Other Comprehensive Income on Derivative	$ 0	$ 0	$ 0	$ (2)