Restructuring and Related Charges (Detail) - Restructuring and related expenses (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring Charges	$ 474,000	$ 416,000	$ 10,449,000
Accelerated Depreciation, Asset Write-Down And Equipment Relocation [Member]
Restructuring Charges		232,000	7,160,000
Gain On Sale Of Martinsville Facility [Member]
Restructuring Charges		(674,000)
Lease Obligations [Member]
Restructuring Charges	418,000	499,000
Severance and other termination costs [Member]
Restructuring Charges	17,000	17,000	1,370,000
Inventory Write-Down [Member]
Restructuring Charges			682,000
Other Cost (Income) [Member]
Restructuring Charges	$ 39,000	$ 342,000	$ 1,237,000