Goodwill and Intangible Assets - Summary of Fair Values of Assets Acquired and Liabilities Assumed as of Acquisition Date (Detail) - USD ($) $ in Thousands			2 Months Ended	12 Months Ended
	May 07, 2019	May 04, 2018	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets [Line Items]
Estimated Fair Value	$ 6,600
Customer relationships
Goodwill And Intangible Assets [Line Items]
Estimated Fair Value	$ 4,200
Estimated Useful Life (Years)	15 years			10 years 1 month 6 days	11 years 7 months 6 days
Customer relationships | TruSight
Goodwill And Intangible Assets [Line Items]
Estimated Useful Life (Years)		2 years 7 months 6 days
Customer relationships | TruSight | HLA
Goodwill And Intangible Assets [Line Items]
Estimated Fair Value		$ 380
Illumina
Goodwill And Intangible Assets [Line Items]
Estimated Fair Value		2,483
Illumina | Acquired in-Process Technology: AlloSeq
Goodwill And Intangible Assets [Line Items]
Estimated Useful Life (Years)			14 years
Illumina | Acquired in-Process Technology: AlloSeq | HCT
Goodwill And Intangible Assets [Line Items]
Estimated Fair Value		$ 2,103