Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Schedule of Concentrations of Risk Percentage

For each significant customer, revenue as a percentage of total revenue for the periods presented and accounts receivable, net as a percentage of total accounts receivable, net as of the periods presented were as follows:

	Revenue			Accounts Receivable, Net
	Year Ended December 31,			December 31,
	2019	2018	2017	2019	2018
Customer A	13.9%	18.4%	31.4%	41.8%	*%
Customer B	*	13.5	*	*	15.1
Customer C	*	15.4	*	*	13.2
Genentech, Inc.	42.1	*	*	*	*
* less than 10%

Summary of Useful Lives Assigned to Property and Equipment

Useful lives assigned to property and equipment are as follows:

Laboratory equipment	3 to 7 years
Leasehold improvements	Shorter of estimated useful life or remaining lease term
Computer equipment and software	3 years
Furniture and office equipment	5 to 10 years