Company Operations and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of business segment | segment		1
Cash and cash equivalents maximum maturity period		3 months
Account receivable, reserves		$ 12,000	$ 12,300
Revenues		522,285	277,743	$ 191,603
Costs and Expenses		219,784	146,590	116,170
Advertising cost expensed	$ 300	900	500
Operating Lease, Right-of-Use Asset		87,000
Operating Lease, Liability, Current		5,000
Operating Lease, Liability, Noncurrent		85,000
Deferred Rent Credit, Current		500
Deferred rent		$ 2,500
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of the assets		3 years
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of the assets		15 years
Grant [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues		$ 0		6,500
Shipping and Handling [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Costs and Expenses		$ 8,300	$ 3,700	$ 3,800