Employee Benefits (Detail) - Information Related to Changes in Projected Benefit Obligation (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Projected benefit obligation at beginning of year	$ 21,160	[1]	$ 19,730	[1]	$ 14,358
Service cost	1,775		1,890		1,875
Interest cost	980		1,010		840
Actuarial loss (gain) due to assumption changes (1)	6,265	[2]	(948)	[2]	1,100	[2]
Additions	1,925				1,961
Benefits paid (2)	(680)	[3]	(390)	[3]	(220)	[3]
Foreign currency impact	180		(132)		(184)
Projected benefit obligation at end of year (3)	$ 31,605	[1]	$ 21,160	[1]	$ 19,730	[1]

[1] Measured as of December 31.

[2] The 2012 actuarial loss was primarily due to a decline in the weighted-average discount rate.

[3] The Company projects the following amounts will be paid in future years to plan participants: $0.5 million in 2013; $2.0 million in 2014; $0.8 million in 2015; $0.9 million in 2016; $1.2 million in 2017; and $7.0 million in the five years thereafter.