Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2018

Pension Benefits

Defined Benefit Plan Disclosure [Line Items]

Components of Net Periodic Benefit Cost for Defined Benefit Plans and Other Postretirement Plans

The following tables provide the components of net periodic benefit cost for its major defined benefit plans and its other postretirement plans.

	Pension Benefits
	Three Months Ended June 30,
	2018						2017
	U.S.			Non-U.S.			U.S.			Non-U.S.
Service cost	$	255		$	527		$	254		$	494
Interest cost	653			351			661			317
Expected return on plan assets	(983		)	(282		)	(944		)	(270		)
Net amortization	685			322			641			395
Net periodic benefit cost	$	610		$	918		$	612		$	936

	Pension Benefits
	Six Months Ended June 30,
	2018						2017
	U.S.			Non-U.S.			U.S.			Non-U.S.
Service cost	$	509		$	1,072		$	508		$	976
Interest cost	1,306			712			1,321			625
Expected return on plan assets	(1,966		)	(572		)	(1,888		)	(534		)
Net amortization	1,370			652			1,283			777
Net periodic benefit cost	$	1,219		$	1,864		$	1,224		$	1,844

Other Postretirement Benefits

Defined Benefit Plan Disclosure [Line Items]

Components of Net Periodic Benefit Cost for Defined Benefit Plans and Other Postretirement Plans

	Other Postretirement Benefits
	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Service cost	$	167		$	152		$	335		$	304
Interest cost	203			204			406			408
Net amortization	(184		)	(199		)	(368		)	(397		)
Net periodic benefit cost	$	186		$	157		$	373		$	315