Collaboration and License Agreements (Details) - USD ($)					1 Months Ended		12 Months Ended
	Apr. 07, 2020	Apr. 02, 2020	May 04, 2019	Sep. 14, 2018	Jun. 30, 2020	Oct. 31, 2018	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jul. 31, 2021	Dec. 04, 2020	May 31, 2019
Collaboration agreement
Aggregate purchase price of common stock								$ 188,784,000	$ 162,406,000
Proceeds from private placement of common stock, net of issuance costs								49,975,000
Collaboration contract asset							9,870,000	13,506,000
Revenue recognized							$ 55,846,000	$ 31,434,000	10,680,000
Common stock, issued shares							95,726,962	87,722,237
Research and development							$ 215,519,000	$ 125,623,000	87,770,000
Janssen Agreement
Collaboration agreement
Sublicense Consideration Represents an Asset Under ASC, Other Assets and Deferred Costs							13,600,000
Revenue recognized							3,000,000.0
Research and development fees cash payments received							3,000,000.0
Milestone Recorded to Deferred Revenue With Remaining Unrecognized Revenue							3,000,000.0
Milestone Receivable Shows an Increase in the Initial Transaction Price							$ 3,000,000.0
First Janssen Cancer Target | Maximum | Janssen Agreement
Collaboration agreement
Development, regulatory, and sales milestones	$ 898,000,000.0
Additional candidate milestone Payments	460,000,000.0
Additional Cancer Targets | Maximum | Janssen Agreement
Collaboration agreement
Development, regulatory, and sales milestones	706,000,000.0
Additional candidate milestone Payments	$ 340,000,000.0
Johnson Johnson Innovation J J D C Inc | Stock Purchase Agreement
Collaboration agreement
Issuance of common stock during period for private placements (in shares)		1,600,000
Common stock per share		$ 31.00
Aggregate purchase price of common stock		$ 50,000,000.0
Equity premium per share		$ 9.93
Aggregate equity premium on shares		$ 16,000,000.0
Proceeds from private placement of common stock, net of issuance costs		34,000,000.0
Johnson Johnson Innovation J J D C Inc | Stock Purchase Agreement | Private Placement
Collaboration agreement
Issuance of common stock during period for private placements (in shares)					1,800,000
Proceeds from private placement of common stock, net of issuance costs					$ 50,000,000.0
Aggregate value of common stock					$ 50,000,000.0
Share issue price (in dollars per share)							$ 28.31
Janssen Biotech Inc
Collaboration agreement
Upfront, non-refundable and non-creditable payment		50,000,000.0					$ 50,000,000.0
Transaction price of the agreement		66,000,000.0
Equity premium		16,000,000.0
Non-refundable upfront payments recorded as deferred revenue		66,000,000.0
Collaboration contract asset		$ 13,600,000					9,500,000
Amortization of sublicense consideration							1,700,000
Revenue recognized								16,800,000
Deferred revenue							48,300,000
Deferred revenue classified as current							21,200,000
Research and development fees cash payments received							31,100,000
Janssen Biotech Inc | Research And Development
Collaboration agreement
Revenue recognized								10,300,000
Janssen Biotech Inc | Upfront Fee and Equity Premium
Collaboration agreement
Revenue recognized								6,500,000
Janssen Biotech Inc | Janssen Agreement
Collaboration agreement
Revenue recognized							43,700,000
Research and development							29,500,000
Upfront cash payment							14,200,000
Ono Pharmaceutical Company Ltd
Collaboration agreement
Transaction price of the agreement				$ 30,000,000.0
Non-refundable upfront payments recorded as deferred revenue				10,000,000.0
Collaboration contract asset											$ 4,000,000.0
Amortization of sublicense consideration							1,200,000	1,800,000
Revenue recognized							12,100,000	14,600,000	9,300,000
Deferred revenue							300,000
Research and development fees cash payments received							17,000,000.0
Milestone payments											10,000,000.0
Aggregate research and development fees payments receivable				20,000,000.0
Collaborative arrangement potential additional milestones				$ 20,000,000.0
Expected ressarch services period				4 years
Payments for research and development fees						$ 5,000,000.0
Non-refundable upfront payments recorded as deferred revenue				$ 10,000,000.0
Collaborative arrangement annual payments receivable recorded as deferred revenue						$ 5,000,000.0
Ono Pharmaceutical Company Ltd | Candidate 2
Collaboration agreement
Percentage of reduction on milestone payments				50.00%
Ono Pharmaceutical Company Ltd | Collaborative Arrangement | Research services
Collaboration agreement
Revenue recognized								5,700,000	6,200,000
Ono Pharmaceutical Company Ltd | Collaborative Arrangement | Upfront Fee
Collaboration agreement
Revenue recognized							6,100,000	2,800,000	3,100,000
Ono Pharmaceutical Company Ltd | Maximum | Candidate 2
Collaboration agreement
Aggregate milestone payments				$ 885,000,000.0
Ono Pharmaceutical Company Ltd | Minimum | Collaborative Arrangement
Collaboration agreement
Profits and losses sharing percentage				50.00%
Ono Pharmaceutical Company Ltd | Ono Letter Agreement
Collaboration agreement
Revenue recognized							6,000,000.0	6,100,000
Milestone payments											10,000,000.0
Milestone payments recorded to deferred revenue											$ 10,000,000.0
Ono Pharmaceutical Company Ltd | Ono Letter Agreement | Sublicense Consideration
Collaboration agreement
Collaboration contract asset							300,000
Sublicense consideration paid								4,000,000.0
Juno Therapeutics, Inc | Collaborative Arrangement
Collaboration agreement
Revenue recognized							0	0	1,400,000
Research term			4 years
Collaboration agreement expiration date			May 04, 2015
Agreement to terminate upon the receipt of research payment												$ 200,000
Juno Therapeutics, Inc | Collaborative Arrangement | Upfront Fee and Equity Premium
Collaboration agreement
Revenue recognized									700,000
Juno Therapeutics, Inc | Collaborative Arrangement | Research services
Collaboration agreement
Revenue recognized									700,000
Amended MSK License
Collaboration agreement
Stock price appreciation milestones potential payments								75,000,000.0
Stock price appreciation milestone, expense							3,500,000	47,700,000	$ 0
Stock price appreciation milestone payable										$ 20,000,000.0
Stock price appreciation milestone, liability							$ 24,200,000	$ 47,700,000