XML 89 R76.htm IDEA: XBRL DOCUMENT v3.8.0.1
EMPLOYEE BENEFIT PLANS (Funded status) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Nonunion Defined Benefit Pension Plan      
Change in benefit obligations      
Benefit obligations at beginning of period $ 152,006 $ 159,607  
Interest cost 4,514 4,572 $ 5,200
Actuarial (gain) loss 6,448 4,202  
Benefits paid (26,491) (16,896)  
Settlement loss 940 521  
Benefit obligations at end of period 137,417 152,006 159,607
Change in plan assets      
Fair value of plan assets at beginning of period 144,805 136,917  
Actual return on plan assets 6,517 11,384  
Employer contributions   13,400  
Benefits paid (26,491) (16,896)  
Fair value of plan assets at end of period 124,831 144,805 136,917
Funded status (12,586) (7,201)  
Accumulated benefit obligation 137,417 152,006  
Supplemental Benefit Plan      
Change in benefit obligations      
Benefit obligations at beginning of period 4,794 4,917  
Interest cost 102 130 123
Actuarial (gain) loss (10) (7)  
Benefits paid (989) (246)  
Benefit obligations at end of period 3,897 4,794 4,917
Change in plan assets      
Employer contributions 989 246  
Benefits paid (989) (246)  
Funded status (3,897) (4,794)  
Accumulated benefit obligation 3,897 4,794  
Postretirement Health Benefit Plan      
Change in benefit obligations      
Benefit obligations at beginning of period 25,532 24,616  
Service cost 489 429 406
Interest cost 1,060 1,017 913
Actuarial (gain) loss (2,251) 133  
Benefits paid (733) (663)  
Benefit obligations at end of period 24,097 25,532 $ 24,616
Change in plan assets      
Employer contributions 733 663  
Benefits paid (733) (663)  
Funded status (24,097) (25,532)  
Accumulated benefit obligation $ 24,097 $ 25,532