Annual report pursuant to Section 13 and 15(d)

Intangibles - Additional Information (Detail)

v3.8.0.1
Intangibles - Additional Information (Detail) - USD ($)
3 Months Ended 8 Months Ended 12 Months Ended
Aug. 01, 2017
May 18, 2015
Sep. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
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    
Recovery of deferred income taxes [note 5]     $ 2,927,000 $ 124,000 $ 127,000 $ 137,000 $ 122,000 $ 118,000 $ 407,000 3,051,000 $ 504,000 $ 407,000
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