Retirement Plans (Details 6) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amounts Recognized in Other Comprehensive Income [Abstract]
Total recognized in other comprehensive (loss) income	$ (4,634)	$ 31,911	$ (31,566)
U.S. Pension Plans
Net Periodic Benefit Cost [Abstract]
Interest cost	6,128	6,417	5,505
Expected return on plan assets	(9,145)	(9,060)	(8,034)
Net amortization: Net actuarial loss (gain)	3,278	2,216	3,432
Net periodic pension cost (benefit)	261	(427)	903
Amounts Recognized in Other Comprehensive Income [Abstract]
Net (loss) gain arising during the year	(6,365)	(19,965)	25,048
Amortization: Net loss (gain) recognized in net periodic pension cost	3,278	2,216	3,432
Total recognized in other comprehensive (loss) income	(3,087)	(17,749)	28,480
U.S. Retiree Healthcare Plan
Net Periodic Benefit Cost [Abstract]
Service cost	577	791	915
Interest cost	470	463	333
Expected return on plan assets	(497)	(435)	(355)
Net amortization: Prior service cost (credit)		(51)	(54)
Net amortization: Net actuarial loss (gain)		(35)
Net periodic pension cost (benefit)	550	733	839
Amounts Recognized in Other Comprehensive Income [Abstract]
Net (loss) gain arising during the year	1,126	(1,155)	1,629
Amortization: Prior service credit recognized in net periodic pension cost		(51)	(54)
Amortization: Net loss (gain) recognized in net periodic pension cost		(35)
Total recognized in other comprehensive (loss) income	1,126	(1,241)	1,575
Non-U.S. Pension Plans
Net Periodic Benefit Cost [Abstract]
Service cost	5,087	4,579	4,467
Interest cost	1,503	2,195	1,966
Expected return on plan assets	(1,542)	(1,520)	(901)
Settlement loss	95	557
Net amortization: Prior service cost (credit)	39	(176)	(216)
Net amortization: Net actuarial loss (gain)	1,031	375	516
Net periodic pension cost (benefit)	6,213	6,010	5,832
Amounts Recognized in Other Comprehensive Income [Abstract]
Prior service cost	645	(796)	(232)
Net (loss) gain arising during the year	3,025	(15,168)	1,940
Amortization: Prior service credit recognized in net periodic pension cost	39	(176)	(216)
Amortization: Net loss (gain) recognized in net periodic pension cost	1,126	932	516
Foreign currency impact on defined benefit plan amounts recognized in other comprehensive (loss) income	1,760	2,287	(497)
Total recognized in other comprehensive (loss) income	$ 6,595	$ (12,921)	$ 1,511

The amount of gains or losses recognized in net periodic benefit cost.

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The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

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An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 30
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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

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Amount of net gain (loss) recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount before tax of cost (credit) of benefit changes attributable to plan participants' prior service resulting from a plan amendment or plan initiation that has not been recognized in net periodic benefit cost (credit).

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Amount before tax of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) related to pension and other postretirement benefit plans.

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Amount before tax, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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Amount before tax of (increase) decrease in the value of the projected benefit obligation related to a change in an actuarial assumption and increase (decrease) in the value of the plan assets resulting from experience different from that assumed, that has not been recognized in net periodic benefit (cost) credit.

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Amount before tax of reclassification adjustment from accumulated other comprehensive income (loss) for actuarial gain (loss) related to pension and other postretirement benefit plans.

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The amount of increase or decrease in other comprehensive income attributed to foreign currency changes. The effects of foreign currency exchange rate changes that are to be disclosed are those applicable to plans of a foreign operation whose functional currency is not the reporting currency.

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No definition available.

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