Revenue Recognition (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended			12 Months Ended
	Aug. 31, 2019	Feb. 28, 2019	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2018	Sep. 30, 2019
Refunds of revenues previously deferred			$ 10,000
Deferred revenue, Long-term			23,816			$ 22,805
Other assets			12,406			14,743
Deferred revenue			32,885			72,930
Deferred revenue, current portion			9,069			50,125
Total revenues			152,316	$ 94,012
Deferred revenue, long-term portion			23,816			22,805
Revenue recognized during the period that was included in deferred revenues at the beginning of the period			30,292
Product
Revenue recognized			1,300	1,000
Cost of revenues			61,322	41,520
Total revenues			$ 118,382	87,046
Product | Minimum
Billing collection period (in months)			9 months
Product | Maximum
Billing collection period (in months)			12 months
Licensing and other
Cost of revenues			$ 5,491	3,458
Total revenues			33,934	$ 6,966
Genetic testing services
Revenue recognized during the period that was included in deferred revenues at the beginning of the period			$ 100
Qiagen
Proceeds from license agreement							$ 5,000
Agreement term			10 years
Revenue, remaining performance obligation							40,000
Revenue recognized during the period that was included in deferred revenues at the beginning of the period			$ 28,600
Qiagen | Volume, regulatory and commercial milestones
Revenue, remaining performance obligation							$ 10,000
Qiagen | Other licensing and other revenue
Refunds of revenues previously deferred			10,000
Deferred revenue			$ 28,600
Laboratory distribution partners | Product | Minimum
Billing collection period (in months)			2 months
Laboratory distribution partners | Product | Maximum
Billing collection period (in months)			3 months
BGI Genomics
Proceeds from license agreement		$ 50,000			$ 35,600
Receivable					$ 2,500
Agreement term		10 years
Deferred revenue, current portion			$ 3,200
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
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			4,200
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
BGI and FMI | Genetic testing services
Revenue recognized during the period that was included in deferred revenues at the beginning of the period			$ 1,600