Revenue Recognition (Details) $ in Thousands	1 Months Ended		3 Months Ended								12 Months Ended
	Aug. 31, 2019 USD ($)	Feb. 28, 2019 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Revenue recognized											$ 2,410	$ 3,324
Revenue, Practical Expedient, Incremental Cost of Obtaining Contract [true false]											true
Deferred revenue, Long-term			$ 23,808				$ 40,058				$ 23,808	40,058
Other assets			12,476				3,317				12,476	3,317
Deferred revenue			79,824				44,189				79,824	44,189
Deferred revenue, current portion			56,016				4,131				56,016	4,131
Total revenues			83,240	$ 77,909	$ 74,355	$ 66,824	66,965	$ 65,280	$ 63,069	$ 62,340	302,328	257,654	$ 209,625
Deferred revenue, long-term portion			23,808				40,058				23,808	40,058
Product
Revenue recognized											2,400	3,300	4,900
Cost of revenues			39,479	40,138	41,382	41,605	40,345	39,477	39,204	39,055	162,604	158,081	135,508
Total revenues											$ 269,881	240,366	203,777
Product | Minimum
Billing collection period (in months)											9 months
Product | Maximum
Billing collection period (in months)											12 months
Licensing and other
Cost of revenues			4,983	$ 3,742	2,443	$ 1,698	$ 2,444	$ 2,202	$ 1,791	1,537	$ 12,866	7,974	4,088
Total revenues											$ 32,447	$ 17,288	$ 5,848
Evercord | Processing and storage services
Number of performance obligations | item											2
Evercord | Processing and storage services | Minimum
Billing collection period (in months)											6 months
Evercord | Processing and storage services | Maximum
Billing collection period (in months)											18 months
Evercord | Processing and storage services | Alternate
Billing collection period (in months)											12 months
Qiagen
Revenue recognized										5,500
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								$ 10,000
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
Proceeds from license agreement		$ 50,000			35,600
Receivable					2,500
Agreement term											10 years
BGI | Sequencing services
Other assets					6,000
BGI | Sequencing products
Other assets					4,000
BGI | Sequencing products and services
Other assets			$ 10,000		$ 10,000						$ 10,000
Foundation Medicine, Inc. ("FMI")
Proceeds from license agreement											16,300
Agreement term	5 years
Automatic renewals, successive period thereafter	1 year
Foundation Medicine, Inc. ("FMI") | Upfront licensing fees and prepaid revenues
Initial transaction price	$ 13,300
Foundation Medicine, Inc. ("FMI") | Developmental, regulatory, and commercial milestones
Initial transaction price	$ 32,000
Foundation Medicine, Inc. ("FMI") | Developmental performance milestones
Proceeds from license agreement											3,000
Foundation Medicine, Inc. ("FMI") | Licensing fees and prepaid revenue
Proceeds from license agreement											$ 13,300