XML 86 R67.htm IDEA: XBRL DOCUMENT v3.8.0.1
Pension and other postretirement benefits - Changes in Plan Assets & Benefit Obligation Recognized in OCI (pre-taxed) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]      
Net loss (gain) $ 7,192 $ 9,522 $ (5,553)
Prior service cost (benefit) (27,396) 0 (1,758)
Amortization of prior service benefit (cost), including recognition due to curtailment 4,950 2,675 8,351
Defined Benefit Pension Plans [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]      
Net loss (gain) (7,507) 7,603  
Prior service cost (benefit) 0 0  
Amortization of net loss, including recognition due to settlement (4,745) (4,666)  
Amortization of prior service benefit (cost), including recognition due to curtailment (106) (106)  
Total amount recognized in other comprehensive loss (12,358) 2,831  
Net periodic benefit cost 3,548 4,541 3,818
Total recognized in net periodic benefit cost and other comprehensive loss (8,810) 7,372  
Other Postretirement Benefit Plans [Member]      
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]      
Net loss (gain) 14,699 1,919  
Prior service cost (benefit) (27,396) 0  
Amortization of net loss, including recognition due to settlement (3,865) (3,537)  
Amortization of prior service benefit (cost), including recognition due to curtailment 5,056 2,781  
Total amount recognized in other comprehensive loss (11,506) 1,163  
Net periodic benefit cost 4,927 7,354 $ 3,775
Total recognized in net periodic benefit cost and other comprehensive loss $ (6,579) $ 8,517