Employee Benefit Plans - Components of Net Periodic (Benefit) Cost (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Pension Plan, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	$ 71	$ 71
Expected return on plan assets	(101)	(107)
Amortization of unrecognized net loss	19	45
Net periodic (benefit) cost	(11)	9
Other Postretirement Benefit Plan, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	8	11
Interest cost	15	15
Amortization of unrecognized net loss		2
Amortization of transition obligation		2
Net periodic (benefit) cost	$ 23	$ 30