Restructuring Expenses - Activity in Restructuring Liability Account (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
2013 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance
Provision-net	5,602
Usage	(1,651)
Ending Balance	3,951
2013 Restructuring [Member] | One-time employee termination benefits [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance
Provision-net	1,211
Usage	(647)
Ending Balance	564
2013 Restructuring [Member] | Lease/rental terminations [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance
Provision-net	3,201
Usage	138
Ending Balance	3,339
2013 Restructuring [Member] | Fixed asset write-offs, transition travel, other [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance
Provision-net	1,190
Usage	(1,142)
Ending Balance	48
2012 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	8
Provision-net
Usage	(4)
Reclass
Ending Balance	4
2012 Restructuring [Member] | One-time employee termination benefits [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	8
Provision-net
Usage
Reclass	(4)
Ending Balance	4
2012 Restructuring [Member] | Lease/rental terminations [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance
Provision-net
Usage
Reclass
Ending Balance
2012 Restructuring [Member] | Relocation, move, other expenses [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance
Provision-net
Usage	(4)
Reclass	4
Ending Balance