Retirement Benefit Plans (Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Current year actuarial loss (gain)	$ 2,816	$ 2,181	$ 8,896
Amortization of actuarial loss	(910)	(1,059)	(837)
Current year prior service cost	0	147	360
Amortization of prior service cost (credit)	(58)	(50)	(32)
Settlements	(90)	0	0
Total recognized in other comprehensive loss (income)	1,758	1,219	8,387
Non-U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Current year actuarial loss (gain)	318	(128)	(94)
Amortization of actuarial loss	(13)	(146)	(112)
Settlements	0	(37)	0
Total recognized in other comprehensive loss (income)	305	(311)	(206)
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Current year actuarial loss (gain)	(25)	226	613
Amortization of actuarial loss	(132)	(91)	(66)
Amortization of prior service cost (credit)	107	107	107
Total recognized in other comprehensive loss (income)	$ (50)	$ 242	$ 654