Intangibles - Additional Information (Detail) - USD ($) |
1 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|
Aug. 01, 2017 |
May 18, 2015 |
Aug. 31, 2017 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Finite Lived Intangible Assets [Line Items] | ||||||
| Intangible assets, Fair Value | $ 8,600,000 | $ 3,100,000 | ||||
| Intangible assets, Useful life | 6 years | 14 years | ||||
| Loss on disposition [note 5] | $ 8,610,000 | |||||
| License agreement amortization expense | $ 200,000 | $ 200,000 | ||||
| Impairment of intangible assets | $ 0 | |||||
| Apatorsen License Agreements [Member] | ||||||
| Finite Lived Intangible Assets [Line Items] | ||||||
| Loss on disposition [note 5] | $ 8,600,000 | |||||
| Recovery of deferred income taxes [note 5] | $ 2,900,000 | |||||
| X | ||||||||||
- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. No definition available.
|
| X | ||||||||||
- Definition Fair value portion of assets, excluding financial assets, that lack physical substance, having a limited useful life. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- 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. No definition available.
|
| X | ||||||||||
- Definition Amount of gain (loss) on sale or disposal of intangible assets. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Details
|