Goodwill and Intangible Assets - Summary of Intangible Assets (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Intangible assets with finite lives:
Gross Carrying Amount	$ 37,875
Accumulated Amortization	(3,419)
Foreign Currency Translation	(149)
Net Carrying Amount	34,307
Customer Relationships [Member]
Intangible assets with finite lives:
Gross Carrying Amount	12,678
Accumulated Amortization	(1,186)
Foreign Currency Translation	(76)
Net Carrying Amount	11,416
Customer Relationships [Member] | Allenex [Member]
Intangible assets with finite lives:
Gross Carrying Amount	12,650
Accumulated Amortization	(1,184)
Foreign Currency Translation	(77)
Net Carrying Amount	$ 11,389
Estimated useful life of identified intangible asset	13 years 3 months 18 days
Customer Relationships [Member] | Conexio [Member]
Intangible assets with finite lives:
Gross Carrying Amount	$ 28
Accumulated Amortization	(2)
Foreign Currency Translation	1
Net Carrying Amount	$ 27
Estimated useful life of identified intangible asset	8 years 3 months 19 days
Trademarks [Member]
Intangible assets with finite lives:
Gross Carrying Amount	$ 2,260
Accumulated Amortization	(273)
Foreign Currency Translation	48
Net Carrying Amount	$ 2,035
Estimated useful life of identified intangible asset	13 years 3 months 18 days
Developed Technology [Member] | SSP [Member]
Intangible assets with finite lives:
Gross Carrying Amount	$ 11,650
Accumulated Amortization	(1,652)
Foreign Currency Translation	(106)
Net Carrying Amount	$ 9,892
Estimated useful life of identified intangible asset	8 years 3 months 19 days
Acquired Technology - QTYPE
Intangible assets with finite lives:
Gross Carrying Amount	$ 4,510
Accumulated Amortization	(298)
Foreign Currency Translation	(20)
Net Carrying Amount	$ 4,192
Estimated useful life of identified intangible asset	13 years 3 months 18 days
Acquired Technology SBT [Member]
Intangible assets with finite lives:
Gross Carrying Amount	$ 127
Accumulated Amortization	(10)
Foreign Currency Translation	5
Net Carrying Amount	$ 122
Estimated useful life of identified intangible asset	8 years 3 months 19 days
Acquired Technology dd-cfDNA [Member]
Intangible assets with finite lives:
Gross Carrying Amount	$ 6,650	[1]
Accumulated Amortization	0	[1]
Foreign Currency Translation	0	[1]
Net Carrying Amount	$ 6,650	[1]
Estimated useful life of identified intangible asset	13 years 1 month 6 days	[1]

[1] The dd-cfDNA balance was initially classified as acquired in-process technology upon the acquisition of IMX in 2014, but was reclassified as an intangible asset with a finite life on September 30, 2017 based on confirmation of the Medicare reimbursement rate for Allosure, the Company’s dd-cfDNA solution, which was commercially launched on October 9, 2017.