Restructuring Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 887	$ 2,462
Charges to operations	1,371	685
Non Cash Adjustments		(226)
Charges settled in cash	(2,254)	(2,034)
Ending Balance	4	887
Workforce | 2012 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0	0
Charges to operations	1,371	0
Non Cash Adjustments		0
Charges settled in cash	(1,367)	0
Ending Balance	4	0
Workforce | 2011 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0	0
Charges to operations	0	548
Non Cash Adjustments		0
Charges settled in cash	0	(548)
Ending Balance	0	0
Workforce | 2010 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0	296
Charges to operations	0	41
Non Cash Adjustments		(117)
Charges settled in cash	0	(220)
Ending Balance	0	0
Facilities Related | 2011 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0	0
Charges to operations	0	96
Non Cash Adjustments		(86)
Charges settled in cash	0	(10)
Ending Balance	0	0
Facilities Related | 2010 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning Balance	653	1,585
Charges to operations	0	0
Non Cash Adjustments		0
Charges settled in cash	(653)	(932)
Ending Balance	0	653
Facilities Related | 2009 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Beginning Balance	234	581
Charges to operations	0	0
Non Cash Adjustments		(23)
Charges settled in cash	(234)	(324)
Ending Balance	$ 0	$ 234