Debt - Summary of Term Debt (Details) - Senior Notes $ in Millions	Mar. 31, 2020 USD ($)
Debt Instrument [Line Items]
Unamortized premium (discount) and issuance costs, net	$ (33)
Total carrying amount of term debt	$ 4,967
Fixed-rate 2.200% notes
Debt Instrument [Line Items]
Fixed interest rate	2.20%
Total term debt	$ 1,000
Effective Interest Rate	2.39%
Fixed-rate 2.400% notes
Debt Instrument [Line Items]
Fixed interest rate	2.40%
Total term debt	$ 1,250
Effective Interest Rate	2.52%
Fixed-rate 2.650% notes
Debt Instrument [Line Items]
Fixed interest rate	2.65%
Total term debt	$ 1,250
Effective Interest Rate	2.78%
Fixed-rate 2.850% notes
Debt Instrument [Line Items]
Fixed interest rate	2.85%
Total term debt	$ 1,500
Effective Interest Rate	2.96%