Utilization of Components of Accrued Exit Costs (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring Cost and Reserve [Line Items]
Exit Costs Beginning Balance	$ 2,234	$ 5,462
Amount provided for during period	125	1,348	5,464
Amount paid during period	(2,359)	(4,576)	(2)
Exit Costs Ending Balance		2,234	5,462
Termination benefits
Restructuring Cost and Reserve [Line Items]
Exit Costs Beginning Balance	2,234	4,843
Amount provided for during period	125	980	4,843
Amount paid during period	(2,359)	(3,589)
Exit Costs Ending Balance		2,234	4,843
Other associated costs
Restructuring Cost and Reserve [Line Items]
Exit Costs Beginning Balance		619
Amount provided for during period		368	621
Amount paid during period		(987)	(2)
Exit Costs Ending Balance			$ 619