Net Periodic Pension Cost (Detail) (Pension Plans, Defined Benefit, USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 80		[1]	$ 236		[1]
Interest cost	21		[1]	63		[1]
Expected return on plan assets	(15)		[1]	(45)		[1]
Amortization of prior service cost	6		[1]	17		[1]
Amortization of transition obligation	12		[1]	38		[1]
Net periodic pension cost	$ 104		[1]	$ 309		[1]

[1] As stated in Note 1 to the Consolidated Financial Statements in its 2012 Annual Report on Form 10-K, the Company began accounting for its pension plans as defined benefit plans in the fourth quarter of 2012 as a correction of an error. Prior to that date, no amounts were recognized in the first three quarters of 2012.