Stock-Based Compensation Plans - Summarizes Transactions of SEUs (Detail) - Stock Equivalent Units [Member]	3 Months Ended
	Mar. 31, 2020 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Number of SEUs, Beginning balance | shares	390,816
Granted at discount, Number of SEUs | shares	103,607
Granted at market value, Number of SEUs | shares	3,634
Exercised, Number of SEUs | shares	(81,557)
Forfeited, Number of SEUs | shares	(9,536)
Outstanding, Number of SEUs, Ending balance | shares	406,964
Outstanding, Weighted Average Exercise Price, Beginning balance	$ 3.69
Granted at discount, Weighted Average Exercise Price	0.00
Granted at market value, Weighted Average Exercise Price	95.70
Exercised, Weighted Average Exercise Price	0.94
Forfeited, Weighted Average Exercise Price	1.53
Outstanding, Weighted Average Exercise Price, Ending balance	4.17
Outstanding, Weighted Average Grant-Date Fair Value	59.91
Granted at discount, Weighted Average Grant-Date Fair Value	77.33
Granted at market value, Weighted Average Grant-Date Fair Value	18.69
Exercised, Weighted Average Grant-Date Fair Value	60.35
Forfeited, Weighted Average Grant-Date Fair Value	58.85
Outstanding, Weighted Average Grant-Date Fair Value	$ 63.92