Property Under Capital Leases Included with Property, Plant and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Capital Leased Assets [Line Items]
Less: accumulated depreciation	$ (2,845)	$ (2,720)
Capital Leases, Balance Sheet, Assets by Major Class, Net	6,463	5,899
Buildings
Capital Leased Assets [Line Items]
Capital leased assets	768	518
Machinery and equipment
Capital Leased Assets [Line Items]
Capital leased assets	3,381	2,998
Vehicles
Capital Leased Assets [Line Items]
Capital leased assets	5,114	5,103
Office equipment and furniture
Capital Leased Assets [Line Items]
Capital leased assets	$ 45	$ 0