The Company, Business Activities and Basis of Presentation - Composition of Net Revenues Recognized Disaggregated by Source (Detail) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Total net revenues		$ 12,047,166	$ 917,471	$ 29,803,356	$ 2,364,020
Commercial Revenues [Member] | Contracted Payers [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues	[1]	6,920,315	261,620	13,234,199	761,808
Commercial Revenues [Member] | Non-Contracted Payers [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		5,058,939	579,398	16,400,102	1,396,811
Development Services Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		33,429	38,453	72,715	98,782
Kits and Blood Collection Tubes [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		$ 34,483	$ 38,000	$ 96,340	$ 106,619

[1] Includes Medicare, Medicare Advantage, and CARES Act as reimbursement amounts are fixed.