Income Tax Effects Allocated to and Cumulative Balance of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (445)
Pretax Amount	(6,295)
Tax Effect	101
Net-of-Tax Amount	(6,396)
Ending Balance	(6,841)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(158)
Pretax Amount	(6,743)
Tax Effect	(60)
Net-of-Tax Amount	(6,683)
Ending Balance	(6,841)
Change in Accumulated OCI Related to Postretirement Healthcare Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(287)
Pretax Amount	448
Tax Effect	161
Net-of-Tax Amount	$ 287