Estimated Useful life of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2016
Computer equipment | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	2 years
Computer equipment | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	3 years
Furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	5 years
Developed software | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	1 year
Developed software | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	3 years
Purchased Software and Digital Assets | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	3 years
Purchased Software and Digital Assets | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	5 years
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, Estimated Useful Life	Shorter of expected useful life or lease term