Summary of Other Expense, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Nonoperating Income Expense [Abstract]
Interest expense	$ (7,518)	$ (10,681)	$ (22,279)	$ (26,460)
Interest income	1,293	1,477	5,758	5,236
Amortization of investment discount	4,089	2,295	13,002	5,123
Other expense	(374)	(59)	(25)	(570)
Other loss	$ (2,510)	$ (6,968)	$ (3,544)	$ (16,671)