Activity Related to Liability for Special Charges (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
Special Charges [Line Items]
Beginning Balance	$ 11,560
Payments	(2,393)
Ending Balance	9,167	[1]
Employee Termination Costs
Special Charges [Line Items]
Beginning Balance	8,225
Payments	(2,358)
Ending Balance	5,867	[1]
Lease Termination Costs
Special Charges [Line Items]
Beginning Balance	3,335
Payments	(35)
Ending Balance	$ 3,300	[1]

[1] Of the $9.2 million remaining liability for special charges, $3.6 million is expected to be paid in the remainder of 2017, $2.6 million is expected to be paid in 2018, $1.2 million is expected to be paid in 2019, $0.4 million is expected to be paid in 2020 and the remaining balance of $1.4 million is expected to be paid from 2021 to 2025.