Capital Stock - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 06, 2018
Capital Stock [Line Items]
The par value of common stock	$ 0.40
Common stock shares authorized	800,000,000	800,000,000
Preferred stock shares authorized	250,000
Preferred stock par value per share	$ 4.00
Preferred stock shares issued	0
Preferred stock shares outstanding	0
Dividends declared per share	$ 1.6025	$ 1.5400	$ 1.5125
Repurchase of common stock	$ 298,541,000	$ 853,997,000	$ 90,304,000
Common Stock [Member]
Capital Stock [Line Items]
Share repurchase program, available repurchase amount	$ 1,200,000,000
Common Stock [Member] | Maximum [Member]
Capital Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 2,000,000,000.0