Quarterly report pursuant to Section 13 or 15(d)

Benefit Plans - Net Periodic Pension Expense Benefit (Details)

v3.10.0.1
Benefit Plans - Net Periodic Pension Expense Benefit (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Defined Benefit Pension Plans | U.S.        
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)        
Service cost $ 243 $ 305 $ 776 $ 914
Interest cost 2,395 2,536 7,137 7,608
Expected return on plan assets (3,165) (3,061) (9,515) (9,183)
Amortization of net loss 0 0 0 0
Curtailment gain recognized     (576) 0
Net periodic expense (benefit) (527) (220) (2,178) (661)
Defined Benefit Pension Plans | Foreign        
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)        
Service cost 933 859 2,665 2,642
Interest cost (601) 1,339 2,512 4,024
Expected return on plan assets 453 (1,111) (2,494) (3,329)
Amortization of net loss 13 0 38 0
Curtailment gain recognized     0 0
Net periodic expense (benefit) 798 1,087 2,721 3,337
Supplemental Retirement Plans        
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)        
Interest cost 110 123 330 370
Net periodic expense (benefit) 110 123 330 370
Other Postretirement Benefits Plans        
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)        
Service cost 3 5 12 15
Interest cost 43 40 108 122
Amortization of prior service credit (40) (19) (79) (58)
Amortization of net loss (11) (19) (33) (58)
Net periodic expense (benefit) $ (5) $ 7 $ 8 $ 21