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OPERATING LEASES (Details) - USD ($) |  | 1 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 10, 2019 | Oct. 31, 2019 | Dec. 31, 2019 | Oct. 01, 2019 | Apr. 30, 2019
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease, right-of-use assets |  |  | $ 2,497,000 |  |
Operating lease liability |  |  | 2,554,000 |  |
Operating lease initial term, aggregate minimum future lease payments |  |  | $ 8,275,000 |  |
Menlo Park Office Space Lease |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease term, additional period extension | 2 months |  |  |  |
New Jersey Office Space Lease |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease, initial term |  |  |  |  | 11 years
Operating lease term, option to extend additional period |  |  |  |  | 5 years
Operating lease, right-of-use assets |  |  |  | $ 2,356,000 |
Operating lease liability |  |  |  | $ 2,356,000 |
Operating lease, percentage of discount rate |  |  |  | 8.00% |
Menlo Park Lease and New Jersey Lease | Maximum |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease, percentage of discount rate |  |  | 8.00% |  |
Operating lease,remaining lease term |  |  | 10 years 9 months 18 days |  |
Menlo Park Lease and New Jersey Lease | Minimum [Member] |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease, percentage of discount rate |  |  | 5.00% |  |
Operating lease,remaining lease term |  |  | 3 months |  |
Foster City Office Space Lease |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease, initial term |  | 87 months |  |  |
Operating lease term, option to extend additional period |  | 5 years |  |  |
Operating lease initial term, aggregate minimum future lease payments |  | $ 4,400,000 |  |  |
Operating lease, rent abatement period |  | 3 months |  |  |

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Discount rate used by lessee to determine present value of operating lease payments. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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