Summary of Changes in Restructuring-Related Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 56	$ 2,284
Costs Incurred	45	279	$ 14,732
Cash Payments	(103)	(2,201)
Non-cash Settlements	0	0
Adjustments and Other	2	(306)
Ending Balance	0	56	2,284
Severance and related employee benefits
Restructuring Cost and Reserve [Line Items]
Beginning Balance	32	2,215
Costs Incurred	0	0
Cash Payments	(32)	(1,885)
Non-cash Settlements	0	0
Adjustments and Other	0	(298)
Ending Balance	0	32	2,215
Contract termination costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0	0
Costs Incurred	0	0
Cash Payments	0	0
Non-cash Settlements	0	0
Adjustments and Other	0	0
Ending Balance	0	0	0
Other costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance	24	69
Costs Incurred	45	279
Cash Payments	(71)	(316)
Non-cash Settlements	0	0
Adjustments and Other	2	(8)
Ending Balance	$ 0	$ 24	$ 69