Share-Based Compensation - Schedule of Grant Date Fair Values of Awards Using Monte Carlo Simulation Valuation Model (Detail)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	[1]	19.50%	20.00%	25.50%
Expected volatility, maximum	[2]	21.50%	24.00%	29.50%
Risk-free rate, minimum		1.80%	2.40%	1.20%
Risk-free rate, maximum		2.40%	2.70%	1.50%
Expected term		3 years	3 years
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term				2 years
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term				3 years

[1] Due to limited trading history of our common stock, we used the historical and implied volatilities of our peer group in addition to our historical and implied volatilities over the performance period to estimate appropriate expected volatilities. For the years ended December 31, 2019, 2018 and 2017, the weighted average expected volatility was 20.5%, 24.0% and 28.4%, respectively.

[2] Dividends are assumed to be reinvested in shares of our common stock and dividends will not be paid unless shares vest.