Revenue Recognition - Remaining Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, current portion	$ 4,928	$ 4,131
Deferred revenue	44,626	44,189
Deferred revenue, noncurrent	39,698	$ 40,058
Evercord
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, noncurrent	3,300
Qiagen
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	40,000
Deferred revenue, noncurrent	36,400
Qiagen | The Qiagen Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	9,000
Deferred revenue, current portion	2,600
Genetic testing services and provision of IVD kits
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, current portion	600
Tests from cloud-based Constellation software
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, current portion	500
Storage services | Evercord
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, current portion	$ 1,200