Derivatives - Cash Flow Hedges (Details) - Cash flow hedge - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivatives in Cash Flow Hedging Relationships
Accumulated other comprehensive income (loss), unrealized gain (loss) on cash flow hedges		$ (31)
After-tax net unrealized gain (loss) anticipated to be reclassified from AOCI to the income statement within next twelve months		42
After-tax net unrealized gain (loss) anticipated to be reclassified from AOCI to the Income Statement in the next fiscal year		20
After-tax unrealized gain (loss) anticipated to be reclassified from AOCI to the Income Statement after the next fiscal year		$ (93)
Foreign currency forward/option contracts
Derivatives in Cash Flow Hedging Relationships
Maximum length of time hedged in cash flow hedge		36 months
Interest rate swap contracts
Derivatives in Cash Flow Hedging Relationships
Accumulated other comprehensive income (loss), unrealized gain (loss) on cash flow hedges		$ (112)
Accumulated other comprehensive income (loss), unrealized gain (loss) on cash flow hedges		(143)
Derivative notional amount			$ 1,200	$ 600	$ 200
Derivative notional amount			$ 700
Additional derivative notional		$ 743
Termination Of Derivative	$ 500