Description of Business	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of BusinessMirati Therapeutics, Inc. (“Mirati” or the “Company”) is a commercial-stage oncology company developing product candidates to address the genetic and immunological promoters of cancer. The Company was incorporated under the laws of the State of Delaware on April 29, 2013 as Mirati Therapeutics, Inc. and is located in San Diego, California. The Company has a wholly-owned subsidiary, Mirati Therapeutics B.V. (“Mirati B.V.”), which was formed on August 3, 2021 in Amsterdam, Netherlands, and a wholly-owned subsidiary, Mirati Therapeutics (Suisse) GmbH (“Mirati Suisse”), which was formed on May 24, 2022 in Zug, Switzerland. The Company operates as one business segment, primarily in the United States. The Company’s common stock has been listed on the Nasdaq Global Select Market since June 5, 2018, and was previously listed on the Nasdaq Capital Market since July 15, 2013, under the ticker symbol “MRTX.”The Company’s former wholly-owned subsidiary in Canada, MethylGene, Inc. (“MethylGene”), which was formed on May 8, 2013 pursuant to an arrangement agreement between the Company and MethylGene, was reorganized in 2022 and formally dissolved in December 2022. As a result of the reorganization, the Company recognized a gain of $9.5 million within other income during the year ended December 31, 2022, which represented the cumulative foreign currency translation gain within accumulated other comprehensive income.