Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($) Customer	Mar. 31, 2020 USD ($) Customer	Dec. 31, 2020 USD ($) Customer	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Foreign currency, losses from remeasurements	$ 0	$ 85,000
Receivables from contract with customers	216,509,000		$ 183,857,000
Contract liability	13,960,000		26,576,000
Contract with customer liability, revenue recognized	$ 18,800,000	242,000
Practical expedient not to disclose amount of transaction price allocated to unsatisfied performance obligations	true
Reagents and supplies	$ 25,684,000		16,491,000
Provision for credit losses for accounts receivable	$ 1,064,000	121,000
Securities maturity period from date of purchase	3 years
Stockholders' equity	$ 801,566,000	81,372,000	569,387,000	$ 82,777,000
Cumulative tax effect	$ 239,000
Accounting Standards Update [Extensible List]	ASU 2016-13
Accounting standards update, adopted	true
Accounting standards update, immaterial effect	true
Retained Earnings (Accumulated Deficit)
Summary Of Significant Accounting Policies [Line Items]
Stockholders' equity	$ 350,924,000	$ (65,385,000)	150,881,000	$ (63,429,000)
Cumulative tax effect	$ 239,000
2019-12
Summary Of Significant Accounting Policies [Line Items]
Accounting standards update, adopted	true
Accounting standards update, immaterial effect	true
Cumulative Effect, Period of Adoption, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Stockholders' equity			(887,000)
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings (Accumulated Deficit)
Summary Of Significant Accounting Policies [Line Items]
Stockholders' equity			(887,000)
Cumulative Effect, Period of Adoption, Adjustment | ASU 2016-13 | Retained Earnings (Accumulated Deficit)
Summary Of Significant Accounting Policies [Line Items]
Stockholders' equity	$ 887,000
Other Current Assets
Summary Of Significant Accounting Policies [Line Items]
Contract assets from contract with customers	506,000		$ 1,400,000
Other Long-Term Assets | Cumulative Effect, Period of Adoption, Adjustment | ASU 2016-13 | Retained Earnings (Accumulated Deficit)
Summary Of Significant Accounting Policies [Line Items]
Cumulative tax effect	$ 239,000
Customer Concentration Risk | Revenue
Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer	1	0
Concentration risk, percentage	25.00%	10.00%
Customer Concentration Risk | Accounts Receivable | Minimum
Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer	0		0
Concentration risk, percentage	10.00%		10.00%