Equity-Based Compensation - Stock Options (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable shares, end of year	2,063
Exercisable, weighted average per share exercise price	$ 52.90
Exercise of common stock options	$ 67	$ 52	$ 95
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of awards	10 years
Outstanding shares, beginning of year	4,441
Granted, shares	839
Exercised, shares	(1,278)
Forfeited or expired, shares	(64)
Outstanding shares, end of year	3,938	4,441
Exercisable shares, end of year	2,063
Outstanding, Weighted Average Per Share Fair Value, beginning of year	$ 59.46
Granted, Weighted Average Per Share Fair Value	98.90
Exercised, Weighted Average Per Share Fair Value	107.96
Forfeited or expired, Weighted Average Per Share Fair Value	83.20
Outstanding, Weighted Average Per Share Fair Value, end of year	69.66	$ 59.46
Exercisable, weighted average per share exercise price	$ 52.90
Weighted average remaining contractual term of stock options outstanding	6 years 6 months
Aggregate intrinsic value of stock options outstanding based on the market value of company's common stock	$ 174
Aggregate intrinsic value of stock options exercisable based on the market value of company's common stock	126
Exercise of common stock options	67	$ 52	95
Aggregate intrinsic value of stock options exercised	$ 71	$ 41	$ 71
First Anniversary [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting (as a percent)	25.00%
Second Anniversary [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting (as a percent)	25.00%
Third Anniversary [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting (as a percent)	50.00%