XML 127 R112.htm IDEA: XBRL DOCUMENT v3.6.0.2
Components of Net Periodic Benefit Cost of Health and Welfare Plan (Detail) - Post-Retirement Benefits - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Components of Net Periodic Benefit Cost:      
Service cost $ 5 $ 4 $ 4
Interest cost 639 700 759
Amortization of past-service liability (249) (249) (249)
Amortization of net actuarial loss 326 383 474
Net periodic benefit cost $ 721 $ 838 $ 988