The Company, Business Activities and Basis of Presentation - Composition of Net Revenues Recognized Disaggregated by Source (Detail) - USD ($)		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Total net revenues		$ 1,024,239	$ 806,943
Commercial Revenues [Member] | Contracted Payers [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues	[1]	481,420	337,946
Commercial Revenues [Member] | Non-Contracted Payers [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		500,321	424,363
Development Services Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		$ 42,498	$ 44,634

[1] Includes Medicare and Medicare Advantage, as reimbursement amounts are fixed. Also includes other income from sales of CEE-Sure blood collection tubes and research-use-only (RUO) test kits.