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Stock-based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Oct. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation arrangement by share-based payment award, options, outstanding, number (in shares) | 10,098,929 | 8,373,921 |  |
Weighted average exercise price (in dollars per share) | $ 18.58 | $ 21.47 |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |  |
Stock-based compensation expense | $ 20,437 | $ 23,126 | $ 20,676 |
Equity Incentive Plan 2003 |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation arrangement by share-based payment award, options, outstanding, number (in shares) | 65,103 |  |  |
Weighted average exercise price (in dollars per share) | $ 5.90 |  |  |
Stock Incentive Plan 2013 |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation, number of shares authorized (in shares) |  |  |  | 1,960,168
Increased number of shares authorized (in shares) | 15,816,949 |  |  |
Share-based compensation arrangement by share-based payment award, options, outstanding, number (in shares) | 10,033,826 |  |  |
Weighted average exercise price (in dollars per share) | $ 18.66 |  |  |
Percentage of common stock share outstanding | 4.00% |  |  |
Research and development |  |  |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |  |
Stock-based compensation expense | $ 10,094 | 11,337 | 10,833 |
General and administrative |  |  |  |
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |  |  |  |
Stock-based compensation expense | $ 10,343 | $ 11,789 | $ 9,843 |

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- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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