Summary of Restructuring Activity (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	$ 1,043
Cash payments	(403)
Restructuring reserve, ending balance	640
Personnel
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	243
Cash payments	(243)
Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance	800
Cash payments	(160)
Restructuring reserve, ending balance	$ 640