Annual report pursuant to Section 13 and 15(d)

Income Tax - Summary of Years Open to Examination under Different Jurisdiction (Detail)

v3.3.1.900
Income Tax - Summary of Years Open to Examination under Different Jurisdiction (Detail)
 12 Months Ended
Dec. 31, 2015
Earliest Tax Year [Member] | Canada [Member]  
Income Tax Examination [Line Items]  
Years open to examination 2008
Earliest Tax Year [Member] | US [Member]  
Income Tax Examination [Line Items]  
Years open to examination 2012
Latest Tax Year [Member] | Canada [Member]  
Income Tax Examination [Line Items]  
Years open to examination 2015
Latest Tax Year [Member] | US [Member]  
Income Tax Examination [Line Items]  
Years open to examination 2015