Derivative Instruments and Hedging Activities - Classification and Fair Value Amounts of Derivative Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 29	$ 21
Derivative liability, fair value	233	54
Derivative instruments designated as hedges
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	24	20
Derivative liability, fair value	229	52
Derivative instruments designated as hedges | Interest rate contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	10
Derivative instruments designated as hedges | Interest rate contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	226	52
Derivative instruments designated as hedges | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	24	10
Derivative instruments designated as hedges | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3	0
Undesignated derivative instruments | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	5	1
Undesignated derivative instruments | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ 4	$ 2