Supplementary Cash Flow Information - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Schedule of Cash Flow, Supplemental [Line Items]
Equipment and software acquired under capital lease obligations	$ 3,800,000	$ 5,200,000
Financing agreement for perpetual software licenses
Schedule of Cash Flow, Supplemental [Line Items]
Financing agreement amount	$ 0