Segment Information and Concentrations of Risk - Schedule of Geographic Concentration of Net Revenues (Detail) (Net Revenues, Geographic Concentration)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration percentage	100.00%	100.00%	100.00%
United States and Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration percentage	91.20%	95.60%	93.10%
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration percentage	1.00%	0.80%	2.40%
Europe, Middle East, Africa and other
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration percentage	6.60%	3.40%	4.10%
Asia and Australia
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration percentage	1.20%	0.20%	0.40%