Net Revenues - Details of Company's Contract Assets (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues [Abstract]
Opening balance		$ 46,951	$ 48,303	$ 45,035	$ 43,366
Impact of opening balance offset with contract liability		41,062	24,427	29,425	21,348
Gross opening balance		88,013	72,730	74,460	64,714
Additions		21,985	5,428	49,098	19,518
Reduction in revenue recognized		(9,814)	(12,752)	(23,374)	(18,826)
Gross closing balance		100,184	65,406	100,184	65,406
Impact of closing balance offset with contract liability		(51,591)	(23,735)	(51,591)	(23,735)
Closing balance	[1]	$ 48,593	$ 41,671	$ 48,593	$ 41,671

[1] Included in "prepaid expenses and other current assets" and "other assets" in the consolidated balance sheet.