Restructuring and Other Charges - Movements in Restructuring and Related Accruals (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Reserve [Roll Forward]
Balance	$ 7,957	$ 3,277	$ 7,882
Additional charges (reversals), net	(5,079)	(19,711)	1,042
Non-cash charges	(418)	(528)	(658)
Payments	(7,418)	(14,503)	(2,905)
Balance	5,200	7,957	3,277
Employee-Related [Member]
Restructuring Reserve [Roll Forward]
Balance	7,539	3,277	7,882
Additional charges (reversals), net	(3,884)	(18,309)	1,700
Non-cash charges	0	0	0
Payments	(7,298)	(14,047)	(2,905)
Balance	4,125	7,539	3,277
Asset - Related/and Other [Member]
Restructuring Reserve [Roll Forward]
Balance	418	0	0
Additional charges (reversals), net	(1,195)	(1,402)	(658)
Non-cash charges	(418)	(528)	(658)
Payments	(120)	(456)	0
Balance	$ 1,075	$ 418	$ 0