Revenues - Additional Information (Detail)		1 Months Ended					3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 12, 2015 USD ($)	Jul. 31, 2017 USD ($)	Jun. 30, 2017 USD ($) Country	May 31, 2017 USD ($)	Aug. 31, 2016 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2018 USD ($) Supplier	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Supplier	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2018 USD ($) PerformanceObligation
Revenue from contract with customer [Line Items]
Accumulated deficit							$ (117,583,000)		$ (117,583,000)		$ (119,510,000)
Maximum value of grant revenue from clinical and regulatory activities	$ 10,400,000				$ 16,600,000
Period of grant	3 years				6 years
Grant expiration period	2018-10
Initial grant revenue from clinical and regulatory activities	$ 1,800,000				$ 7,000,000
Remaining grant revenue from clinical and regulatory activities	$ 8,600,000				$ 9,600,000
Additional contract revenue from clinical and regulatory activities		$ 1,330,000		$ 2,600,000		$ 7,200,000
Contract revenues from clinical and regulatory activities							962,000	$ 454,000	1,799,000	$ 874,000
Deferred revenue							$ 1,621,000		$ 1,621,000		1,314,000
Contract with customer payment terms, description									Payment terms differ by jurisdiction and customer but payment is generally required in a term ranging from 30 to 120 days from date of shipment or satisfaction of the performance obligation.
Reserve for sales return and allowances									$ 197,000		$ 217,000
Customer [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Revenue from contract with customer [Line Items]
Percentage of concentration risk									18.00%		37.00%
Customer [Member] | Net Consolidated Revenue [Member] | Customer Concentration Risk [Member]
Revenue from contract with customer [Line Items]
Percentage of concentration risk							18.00%	20.00%	21.00%	15.00%
Customer One [Member] | Net Consolidated Revenue [Member] | Customer Concentration Risk [Member]
Revenue from contract with customer [Line Items]
Percentage of concentration risk								10.00%
Minimum [Member]
Revenue from contract with customer [Line Items]
Contract with customer payment terms minimum									30 days
Maximum [Member]
Revenue from contract with customer [Line Items]
Contract with customer payment terms minimum									120 days
Sales commissions amortization period									1 year
Long-term Contract [Member]
Revenue from contract with customer [Line Items]
Deferred revenue							$ 358,000		$ 358,000		$ 269,000
Up Front Payment Arrangement [Member]
Revenue from contract with customer [Line Items]
Deferred revenue							1,263,000		1,263,000		$ 1,045,000
Other [Member]
Revenue from contract with customer [Line Items]
Contract revenues from clinical and regulatory activities							958,000	$ 590,000	1,659,000	$ 1,234,000
Ancestry.com DNA LLC [Member] | Litigation Settlement Agreement [Member]
Revenue from contract with customer [Line Items]
Royalty income							$ 2,092,000		$ 3,694,000
DNA Genotek [Member]
Revenue from contract with customer [Line Items]
Number of third-party suppliers to manufacture DNAG's products | Supplier							2		2
Ora Quick HIV Self Test [Member] | Bill & Melinda Gates Foundation [Member]
Revenue from contract with customer [Line Items]
Charitable support agreement term			4 years
Number of countries in which products are sold | Country			50
Maximum amount of funding over the agreement period			$ 20,000,000
Funding received per year			$ 6,000,000					$ 0		$ 0
Support payments recognized in product revenue							$ 1,709,000		$ 2,732,000
Support payments recognized in other revenue							$ 795,000		$ 1,324,000
Charitable support agreement commencement date									2017-06
ASU 2014-09 [Member]
Revenue from contract with customer [Line Items]
Accumulated deficit												$ (119,585,000)
Deferred revenue												$ 1,389,000
ASU 2014-09 [Member] | Drug Testing Kit Sales [Member]
Revenue from contract with customer [Line Items]
Number of performance obligations | PerformanceObligation												2
ASU 2014-09 [Member] | Change in Revenue Recognition [Member]
Revenue from contract with customer [Line Items]
Accumulated deficit												$ (75,000)
Deferred revenue												75,000
ASU 2014-09 [Member] | Change in Revenue Recognition [Member] | Drug Testing Kit Sales [Member]
Revenue from contract with customer [Line Items]
Accumulated deficit												$ 75,000