Retirement Plans	12 Months Ended
Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	15. RETIREMENT PLANS The Company maintains a 401(k) tax deferred saving plan (the “Savings Plan”) for the benefit of qualified employees. Qualified employees may elect to make contributions to the Savings Plan on a biweekly basis, subject to certain limitations. The Company may make contributions to the Savings Plan at the discretion of the Board of Directors. No contributions were made for the years ended December 31, 2019, 2018 and 2017. In 2014, the Company established a defined contribution plan in the U.K. for its U.K.-based employees. The Company contributed $0.5 million, $0.4 million and $0.3 million to the plan for the years ended December 31, 2019, 2018 and 2017, respectively.

The entire disclosure for an entity's employee compensation and benefit plans, including, but not limited to, postemployment and postretirement benefit plans, defined benefit pension plans, defined contribution plans, non-qualified and supplemental benefit plans, deferred compensation, share-based compensation, life insurance, severance, health care, unemployment and other benefit plans.

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-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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