Acquisitions - Summary of Unaudited Pro Forma Financial Information (Detail) - Small Giant [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Total revenue	$ 306,500	$ 238,554	$ 571,903	$ 459,802
Net loss	$ (55,598)	$ (16,740)	$ (177,462)	$ (32,254)
Basic and diluted earnings per share	$ (0.06)	$ (0.02)	$ (0.19)	$ (0.03)