Stock-Based Compensation (Stock Options Outstanding, Exercisable and Activity) (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Number of Shares
Beginning Balance	3,761,000
Granted	588,870
Exercised	(832,177)
Forfeited/Expired	(107,940)
Ending Balance	3,409,753	3,761,000
Vested or expected to vest, at end of period	3,312,698
Exercisable, at end of period	1,819,591
Weighted Average Exercise Price
Beginning Balance (in dollars per share)	$ 90.10
Granted (in dollars per share)	109.74
Exercised (in dollars per share)	73.78
Forfeited/Expired (in dollars per share)	107.41
Ending Balance (in dollars per share)	96.93	$ 90.10
Vested or expected to vest, at end of period (in dollars per share)	96.54
Exercisable, at end of period (in dollars per share)	$ 86.67
Weighted Average Remaining Contractual Life (in years)
Outstanding	6 years 1 month 6 days	6 years 1 month 6 days
Vested or expected to vest, at end of period	6 years 1 month 6 days
Exercisable, at end of period	4 years 4 months 24 days
Intrinsic Value (in millions)
Outstanding	$ 125	$ 61
Vested or expected to vest, at end of period	122
Exercisable, at end of period	$ 85