Schedule of Restructuring and Other Net (Detail) (USD $) In Thousands, unless otherwise specified		3 Months Ended			12 Months Ended	3 Months Ended	12 Months Ended			1 Months Ended	3 Months Ended			12 Months Ended	3 Months Ended	12 Months Ended			1 Months Ended	3 Months Ended			3 Months Ended			12 Months Ended
	Sep. 30, 2012	Sep. 30, 2012 Pre-2011 Activities	Jul. 01, 2012 Pre-2011 Activities	Apr. 01, 2012 Pre-2011 Activities	Dec. 31, 2011 Pre-2011 Activities	Apr. 01, 2012 Q1 2011 Activity	Dec. 31, 2011 Q1 2011 Activity	Apr. 01, 2012 Q2 2011 Activity	Dec. 31, 2011 Q2 2011 Activity	Sep. 30, 2012 Q2 2012 Activity	Jul. 01, 2012 Q2 2012 Activity	Sep. 30, 2012 Q3 2012 Activity	Sep. 30, 2012 Severance And Benefits	Dec. 31, 2011 Severance And Benefits Pre-2011 Activities	Apr. 01, 2012 Severance And Benefits Q1 2011 Activity	Dec. 31, 2011 Severance And Benefits Q1 2011 Activity	Apr. 01, 2012 Severance And Benefits Q2 2011 Activity	Dec. 31, 2011 Severance And Benefits Q2 2011 Activity	Sep. 30, 2012 Severance And Benefits Q2 2012 Activity	Jul. 01, 2012 Severance And Benefits Q2 2012 Activity	Sep. 30, 2012 Severance And Benefits Q3 2012 Activity	Sep. 30, 2012 Facility Exit Costs	Sep. 30, 2012 Facility Exit Costs Pre-2011 Activities	Jul. 01, 2012 Facility Exit Costs Pre-2011 Activities	Apr. 01, 2012 Facility Exit Costs Pre-2011 Activities	Dec. 31, 2011 Facility Exit Costs Pre-2011 Activities
Restructuring Cost and Reserve
Beginning Balance	$ 1,649	$ 1,464	$ 1,673	$ 1,862	$ 3,975	$ 96							$ 360	$ 712	$ 96							$ 1,289	$ 1,464	$ 1,673	$ 1,862	$ 3,263
Provision					117		572		344		286	687		117		572		344		286	687
Change in estimate					(330)					(4)				155					(4)							(485)
Cash payments		(175)	(209)	(189)	(1,900)	(96)	(476)	(229)	(115)	(282)		(327)		(984)	(96)	(476)	(229)	(115)	(282)		(327)		(175)	(209)	(189)	(916)
Ending balance	$ 1,649	$ 1,289	$ 1,464	$ 1,673	$ 1,862		$ 96		$ 229		$ 286	$ 360	$ 360			$ 96		$ 229		$ 286	$ 360	$ 1,289	$ 1,289	$ 1,464	$ 1,673	$ 1,862