Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Schedule of Revenue from Strategic Partnering Collaboration Agreements and Research Activity Grants as a Percentage of Total Revenues

Revenues from major collaboration agreements and research activity grants as a percentage of total revenues were as follows:

	Year Ended December 31,
	2020		2019		2018
Pfizer Inc.	40	%	40	%	47	%
Kite Pharma, Inc.	24	%	34	%	30	%
Biogen MA, Inc.	24	%	—		—
Sanofi Genzyme	5	%	22	%	16	%
Novartis Institutes for BioMedical Research, Inc.	4	%	—		—

Schedule of Cash and Cash Equivalents

A reconciliation of cash, cash equivalents and restricted cash reported within the accompanying Consolidated Balance Sheets to the amounts reported within the accompanying Consolidated Statements of Cash Flows is as follows (in thousands):

	As of December 31,
	2020		2019		2018
Cash and cash equivalents	$	131,329	$	80,428	$	140,418
Non-current restricted cash	1,500		1,500		3,500
Cash, cash equivalents and restricted cash as reported within the Consolidated Statements of Cash Flows	$	132,829	$	81,928	$	143,918

Restrictions on Cash and Cash Equivalents

A reconciliation of cash, cash equivalents and restricted cash reported within the accompanying Consolidated Balance Sheets to the amounts reported within the accompanying Consolidated Statements of Cash Flows is as follows (in thousands):

	As of December 31,
	2020		2019		2018
Cash and cash equivalents	$	131,329	$	80,428	$	140,418
Non-current restricted cash	1,500		1,500		3,500
Cash, cash equivalents and restricted cash as reported within the Consolidated Statements of Cash Flows	$	132,829	$	81,928	$	143,918