Restructuring - Summary of Historical Restructuring Liability (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015
Q1 2015 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability, Beginning balance		$ 330,000
Restructuring expense and adjustments		542,000	$ 3,241,000	$ 3,783,000
Cash payments		(872,000)	(2,911,000)	(3,783,000)
Restructuring liability, Ending balance	$ 0		330,000	0
Q2 2015 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability, Beginning balance	1,860,000
Restructuring expense and adjustments	367,000	12,282,000		12,649,000
Cash payments	(1,736,000)	(10,422,000)		(12,158,000)
Restructuring liability, Ending balance	491,000	1,860,000		491,000
Q1 2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability, Beginning balance	6,663,000	8,082,000	10,009,000	10,009,000
Restructuring expense and adjustments	33,000	30,000	189,000	252,000
Cash payments	(1,491,000)	(1,449,000)	(2,116,000)	(5,056,000)
Restructuring liability, Ending balance	5,205,000	6,663,000	8,082,000	5,205,000
Other Restructuring Plans [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability, Beginning balance	1,933,000	1,957,000	2,857,000	2,857,000
Restructuring expense and adjustments	19,000		31,000	50,000
Cash payments	(1,168,000)	(24,000)	(931,000)	(2,123,000)
Restructuring liability, Ending balance	$ 784,000	$ 1,933,000	$ 1,957,000	$ 784,000