Capital Stock - Share Repurchase Programs (Detail)	Dec. 31, 2019 USD ($)
Equity, Class of Treasury Stock [Line Items]
Remaining Authority	$ 1,334,000,000
October 22, 2018
Equity, Class of Treasury Stock [Line Items]
Amount Authorized	1,000,000,000
Remaining Authority	334,000,000
December 16, 2019
Equity, Class of Treasury Stock [Line Items]
Amount Authorized	1,000,000,000
Remaining Authority	$ 1,000,000,000