Retirement Benefits - Amounts in Accumulated Other Comprehensive Income Loss Expected to be Recognized As Components of Net Periodic Benefit Cost During 2012 (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service cost (credit)	$ (45)
Net loss (gain)	2,975
Total	2,930
Pension Benefits | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service cost (credit)	46	$ 62
Net loss (gain)	21,432	22,478
Total	21,478	22,540
Prior service cost (credit)	13
Net loss (gain)	1,755
Total	1,768
Pension Benefits | Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service cost (credit)	(100)	64
Net loss (gain)	19,304	12,955
Total	19,204	13,019
Prior service cost (credit)	(21)
Net loss (gain)	1,726
Total	1,705
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service cost (credit)	(46)	(117)
Net loss (gain)	(6,009)	(6,386)
Total	(6,055)	$ (6,503)
Prior service cost (credit)	(37)
Net loss (gain)	(506)
Total	$ (543)