Restructuring Charges - Accrual for Severance and Related Costs (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring And Related Activities [Abstract]
Beginning of Period		$ 11,290	$ 12,863	$ 18,985	$ 2,712
Severance & Related Charges	[1],[2]	117	52	389	13,697
Payments		(1,546)	(2,335)	(9,176)	(5,399)
Non-cash Adjustments	[3]	240	(830)	(97)	(1,260)
End of Period		$ 10,101	$ 9,750	$ 10,101	$ 9,750

[1] Includes charges related to COBRA and outplacement services which are assumed to be completed by the third month following an employee’s departure.

[2] Severance payments will result in future cash expenditures through 2018.

[3] Includes cancellations due to employee departures prior to agreed upon end dates, employee transfers to open positions within the organization and subsequent adjustments to severance and related costs.