Employee Benefit Plans - Components of Net Periodic Benefit Costs (Detail) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Supplemental Executive Retirement Benefits [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 85 $ 91 $ 87
Interest cost 35 42 43
Recognition of prior service cost 28 28 28
Amortization of unrecognized loss 61 68   
Total 209 229 158
Long-Term Health Care Plan [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Service cost         
Interest cost 24 30 33
Recognition of prior service cost 17 18 18
Recognized net actuarial loss 5 26   
Total $ 46 $ 74 $ 51