Revenue Recognition (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 28, 2019	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Aug. 31, 2019
Deferred revenue, Long-term			$ 22,805	$ 23,808
Other assets			14,743	12,476
Deferred revenue			72,930	79,824
Deferred revenue, current portion			50,125	56,016
Total revenues			391,005	302,328	$ 257,654
Deferred revenue, long-term portion			22,805	23,808
Revenue recognized during the period that was included in deferred revenues at the beginning of the period			7,246
Product
Revenue recognized			5,400	2,400	3,300
Cost of revenues			185,865	162,604	158,081
Total revenues			367,211	269,881	240,366
Licensing and other
Cost of revenues			17,755	12,866	7,974
Total revenues			23,794	32,447	17,288
Genetic testing services and provision of IVD kits
Revenue recognized during the period that was included in deferred revenues at the beginning of the period			$ 400
Qiagen
Proceeds from license agreement					5,000
Agreement term			10 years
Revenue, remaining performance obligation					40,000
Qiagen | Volume, regulatory and commercial milestones
Revenue, remaining performance obligation					$ 10,000
Qiagen | Prepaid royalties
Revenue recognized			$ 0
BGI Genomics
Proceeds from license agreement	$ 50,000	$ 35,600
Receivable		2,500
Deferred revenue, current portion			3,900
BGI Genomics | Sequencing services
Other assets		6,000
BGI Genomics | Sequencing products
Other assets		4,000
BGI Genomics | Sequencing products and services
Other assets		$ 10,000	10,000
Foundation Medicine ("FMI")
Proceeds from license agreement			$ 0	16,300
Agreement term			5 years
Automatic renewals, successive period thereafter			1 year
Deferred revenue, current portion			$ 6,200
Foundation Medicine ("FMI") | Upfront licensing fees and prepaid revenues
Initial transaction price						$ 13,300
Foundation Medicine ("FMI") | Developmental, regulatory, and commercial milestones
Initial transaction price						$ 32,000
Foundation Medicine ("FMI") | Developmental performance milestones
Proceeds from license agreement				3,000
Foundation Medicine ("FMI") | Licensing fees and prepaid revenue
Proceeds from license agreement				$ 13,300