Fair Value - Additional Information (Detail) CAD in Millions, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2015 CAD	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Fair Value Of Financial Instruments [Line Items]
Contingent consideration obligation arising from acquisitions settlement			$ 1.9	$ 4.3
Amba [Member]
Fair Value Of Financial Instruments [Line Items]
Contingent consideration obligation arising from acquisitions settlement				$ 4.3
Copal [Member]
Fair Value Of Financial Instruments [Line Items]
Remaining ownership interest	33.00%	33.00%	33.00%
CSI [Member]
Fair Value Of Financial Instruments [Line Items]
Contingent consideration obligation arising from acquisitions settlement | CAD		CAD 2.5
Copal Amba [Member] | Call Option [Member]
Fair Value Of Financial Instruments [Line Items]
Contingent consideration payments to acquire remaining shares amount	$ 12.2