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The Company and Summary of Significant Accounting Policies - Additional Information (Detail) | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2020 USD ($) ClinicalTrials | Dec. 31, 2019 USD ($) | Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($)
Targeted or Tracking Stock, Stock [Line Items] |  |  |  |  |  |
Number of clinical stage candidates | ClinicalTrials |  |  | 4 |  |  |
Deferred Revenue Associated With Remaining Performance Obligation | $ 84,800,000 |  | $ 84,800,000 |  |  |
Unrecognized tax benefits | 0 |  | 0 |  | $ 0 |
Revenue Recognised With Performance Obligation | 9,100,000 | $ 700,000 | 12,700,000 | $ 1,500,000 |  |
Accumulated Losses Since Inception | (290,780,000) |  | (290,780,000) |  | (277,234,000) |
Cash And Cash Equivalents,Short Term Investments And Common Stock Proceeds Receivable | 180,100,000 |  | 180,100,000 |  |  |
Contract assets, Current | 10,206,000 | 481,000 | 10,206,000 | 481,000 | $ 604,000 | $ 686,000
Increase in contract assets |  |  | 9,602,000 | (205,000) |  |
US License |  |  |  |  |  |
Targeted or Tracking Stock, Stock [Line Items] |  |  |  |  |  |
Deferred Revenue Associated With Remaining Performance Obligation | 64,500,000 |  | 64,500,000 |  |  |
Ex US License |  |  |  |  |  |
Targeted or Tracking Stock, Stock [Line Items] |  |  |  |  |  |
Deferred Revenue Associated With Remaining Performance Obligation | 20,300,000 |  | 20,300,000 |  |  |
Helsinn License Agreement |  |  |  |  |  |
Targeted or Tracking Stock, Stock [Line Items] |  |  |  |  |  |
Deferred Revenue, Revenue Recognized | 100,000 | 300,000 | 300,000 | 700,000 |  |
KKC Commercialization Agreement And The Helsinn License Agreement |  |  |  |  |  |
Targeted or Tracking Stock, Stock [Line Items] |  |  |  |  |  |
Contract assets, Current | 10,200,000 |  | 10,200,000 |  |  |
Increase in contract assets |  |  | 18,400,000 |  |  |
KKC Agreements and Helsinn License Agreement |  |  |  |  |  |
Targeted or Tracking Stock, Stock [Line Items] |  |  |  |  |  |
Contract with Customer, Liability, Revenue Recognized | $ 9,200,000 | $ 1,000,000 | $ 12,700,000 | $ 1,800,000 |  |

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