Stockholders' Equity (Deficit) - TSR and Summary of Number of PSUs granted Based on TSR and Assumptions Used to Calculate the Grant Date Fair Value Based on Total Shareholder Return (Detail) - $ / shares								12 Months Ended
	Mar. 01, 2020	Feb. 13, 2020	Feb. 12, 2020	Jul. 11, 2019	Feb. 14, 2019	Feb. 13, 2019	Feb. 13, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target level for the determination of performance goals and measures								100.00%
Three-year PSU Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU awards performance period								3 years	3 years	3 years
Number of units granted (in shares)								323,135
granted (in dollars per share)								$ 36.33
PSUs – Total Shareholder Return
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target level for the determination of performance goals and measures								100.00%
Number of units granted (in shares)	31,064	44,206	33,335	20,724	24,905	24,914	56,829
granted (in dollars per share)	$ 29.85	$ 34.08	$ 38.87	$ 55.82	$ 57.34	$ 59.15	$ 43.40
Expected price volatility	23.70%	23.70%	23.70%	23.00%	22.80%	22.80%	22.00%
Risk-free interest rate	0.90%	1.40%	1.40%	1.86%	2.51%	2.55%	2.00%