Annual report pursuant to Section 13 and 15(d)

Benefit Plans - Accumulated Other Comprehensive Income (Details)

v3.8.0.1
Benefit Plans - Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Defined Benefit Pension Plans | U.S.    
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax    
Prior service credit $ 0 $ 0
Net gain (loss) 13,943 12,920
Gross amount recognized 13,943 12,920
Deferred income taxes (3,444) (4,730)
Net amount recognized 10,499 8,190
Defined Benefit Pension Plans | Foreign    
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax    
Prior service credit 0 0
Net gain (loss) (3,923) (2,686)
Gross amount recognized (3,923) (2,686)
Deferred income taxes 1,052 601
Net amount recognized (2,871) (2,085)
Supplemental Retirement Plans    
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax    
Net gain (loss) 761 1,007
Gross amount recognized 761 1,007
Deferred income taxes (188) (384)
Net amount recognized 573 623
Other Postretirement Benefits Plans    
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax    
Prior service credit 366 0
Net gain (loss) 719 1,163
Gross amount recognized 1,085 1,163
Deferred income taxes (200) (286)
Net amount recognized $ 885 $ 877