Subsequent Events (Subsequent Event - Additional Information) (Detail) - Subsequent Event [Member] $ in Millions	May 05, 2020 USD ($)
Subsequent Event [Line Items]
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	100.00%
Debt Instrument, Redemption, Description
Fixed Rate 1.625 Percent Senior Notes Due 2023
Subsequent Event [Line Items]
Face amount of notes issued or redeemed	$ 500
Fixed Rate 2.550 Percent Notes Due 2027
Subsequent Event [Line Items]
Face amount of notes issued or redeemed	$ 750
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	100.00%
Aggregate Principal
Subsequent Event [Line Items]
Face amount of notes issued or redeemed	$ 1,250