Schedule of Restructuring and Other Net (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring Cost and Reserve
Ending balance	$ 1,327
Pre-2010 Activities
Restructuring Cost and Reserve
Beginning Balance	1,862	3,263	12,961
Change in estimate		(485)	(2,432)
Cash payments	(778)	(916)	(7,266)
Ending balance	1,084	1,862	3,263
Q1 2010 Activity
Restructuring Cost and Reserve
Provision			405
Cash payments			(405)
Q2 2010 Activities
Restructuring Cost and Reserve
Beginning Balance		488
Provision			890
Change in estimate		202
Cash payments		(690)	(402)
Ending balance			488
Q3 2010 Activity
Restructuring Cost and Reserve
Beginning Balance		126
Provision			382
Change in estimate		(47)
Cash payments		(79)	(72)
Other			(184)
Ending balance			126
Q4 2010 Activity
Restructuring Cost and Reserve
Beginning Balance		98
Provision		117	98
Cash payments		(215)
Ending balance			98
Q1 2011 Activity
Restructuring Cost and Reserve
Beginning Balance	96
Provision		572
Cash payments	(96)	(476)
Ending balance		96
Q2 2011 Activity
Restructuring Cost and Reserve
Beginning Balance	229
Provision		344
Cash payments	(229)	(115)
Ending balance		229
Q2 2012 Activity
Restructuring Cost and Reserve
Provision	286
Change in estimate	(4)
Cash payments	(282)
Q3 2012 Activity
Restructuring Cost and Reserve
Provision	687
Cash payments	(444)
Ending balance	243
Severance And Benefits
Restructuring Cost and Reserve
Ending balance	243
Severance And Benefits | Pre-2010 Activities
Restructuring Cost and Reserve
Beginning Balance			2,905
Change in estimate			240
Cash payments			(3,145)
Severance And Benefits | Q1 2010 Activity
Restructuring Cost and Reserve
Provision			405
Cash payments			(405)
Severance And Benefits | Q2 2010 Activities
Restructuring Cost and Reserve
Beginning Balance		488
Provision			890
Change in estimate		202
Cash payments		(690)	(402)
Ending balance			488
Severance And Benefits | Q3 2010 Activity
Restructuring Cost and Reserve
Beginning Balance		126
Provision			382
Change in estimate		(47)
Cash payments		(79)	(72)
Other			(184)
Ending balance			126
Severance And Benefits | Q4 2010 Activity
Restructuring Cost and Reserve
Beginning Balance		98
Provision		117	98
Cash payments		(215)
Ending balance			98
Severance And Benefits | Q1 2011 Activity
Restructuring Cost and Reserve
Beginning Balance	96
Provision		572
Cash payments	(96)	(476)
Ending balance		96
Severance And Benefits | Q2 2011 Activity
Restructuring Cost and Reserve
Beginning Balance	229
Provision		344
Cash payments	(229)	(115)
Ending balance		229
Severance And Benefits | Q2 2012 Activity
Restructuring Cost and Reserve
Provision	286
Change in estimate	(4)
Cash payments	(282)
Severance And Benefits | Q3 2012 Activity
Restructuring Cost and Reserve
Provision	687
Cash payments	(444)
Ending balance	243
Facility Exit Costs
Restructuring Cost and Reserve
Ending balance	1,084
Facility Exit Costs | Pre-2010 Activities
Restructuring Cost and Reserve
Beginning Balance	1,862	3,263	10,056
Change in estimate		(485)	(2,672)
Cash payments	(778)	(916)	(4,121)
Ending balance	$ 1,084	$ 1,862	$ 3,263