Restructuring Charges - Accrual for Severance and Related Costs (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring And Related Activities [Abstract]
Beginning of Period		$ 2,712	$ 3,256	$ 6,045
Severance and Related Charges	[1]	24,085	3,979	5,556
Payments		(7,518)	(3,120)	(7,412)
Non-cash Adjustments	[2]	(294)	(1,403)	(933)
End of Period		$ 18,985	$ 2,712	$ 3,256

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

[2] 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.