Canadian Customs Duty Examination (Detail Textuals) - CBSA $ in Millions, $ in Millions			3 Months Ended		6 Months Ended
	Mar. 14, 2018 USD ($)	Mar. 14, 2018 CAD ($)	Jul. 31, 2018 USD ($)	Jul. 31, 2018 CAD ($)	Jul. 31, 2018 USD ($)	Jul. 31, 2018 CAD ($)
Canadian Customs Duty Examination [Line Items]
Value of bond issued for prepayments of additional duties	$ 20.9	$ 26.9
Amendment in prepayments of additional duties	$ 1.1	$ 1.4
Deferred higher dutiable value			$ 2.6	$ 3.4	$ 4.5	$ 5.8