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Organization and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) customer SalesChannel	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of sales channels | SalesChannel		2
Number of customers | customer		2
Maturity threshold of investments classified to cash equivalents		90 days
Percentage of net revenues		10.00%
Percentage of accounts receivable attributable to major customer		10.00%
Sales return period		30 days
Unbilled Contracts Receivable		$ 5,100,000
Goodwill and intangible asset impairment		0	$ 0	$ 0
Goodwill accumulated impairment losses				0
Amount of recognized deferred revenue		1,900,000
Advertising expense	$ 21,900,000	$ 25,400,000		$ 11,900,000
Amortization period for incentive compensation costs		1 year
Computer software and hardware
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life		3 years
Furniture and fixtures
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life		5 years
Byram
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of net revenues		12.00%	14.00%	17.00%
Percentage of accounts receivable attributable to major customer	12.00%	15.00%	12.00%
Edgepark
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of net revenues		15.00%	16.00%	14.00%
Percentage of accounts receivable attributable to major customer	18.00%	19.00%	18.00%
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Customer contract payment terms		30 days
Useful life of finite-lived intangible assets		2 years
Minimum | Machinery and Equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life		4 years
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Customer contract payment terms		90 days
Useful life of finite-lived intangible assets		5 years
Maximum | Machinery and Equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life		15 years

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