Stock-Based Compensation - Summary of Stock Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 846,959	$ 51,763	$ 1,028,914	$ 164,650
Cost of revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	94,385	7,183	120,285	16,520
Sales and marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	263,958	15,898	322,353	56,242
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	256,769	15,031	309,698	49,137
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 231,847	$ 13,651	$ 276,578	$ 42,751