Pensions and Other Post-Employment Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in plan assets
Fair value of plan assets at end of year	$ 187,186	$ 173,494
Pension Benefits [Member]
Change in benefit obligation
Benefit obligation at beginning of year	221,748	253,839
Service cost	7,963	9,724	7,915
Interest cost	10,339	9,936	9,912
Plan amendments	0	0
Actuarial (gain) loss	43,476	(28,581)
Benefit payments from fund	(8,387)	(22,893)
Benefit payments directly by Company	(1,236)	(136)
Expenses paid from assets	(570)	(613)
Medicare Part D subsidy	0	0
Foreign currency exchange rate changes	(1,548)	472
Benefit obligation at end of year	271,785	221,748	253,839
Change in plan assets
Fair value of plan assets at beginning of year	173,494	163,436
Actual return on plan assets	6,852	23,824
Employer contributions	16,145	9,615
Benefit payments from fund	(8,387)	(22,893)
Expenses paid from assets	(569)	(613)
Foreign currency exchange rate changes	(349)	125
Fair value of plan assets at end of year	187,186	173,494	163,436
Funded status at end of year	(84,599)	(48,254)
Amounts recognized in the Consolidated Balance Sheets consist of:
Other assets	1,703	1,321
Other liabilities and accrued items	(753)	(1,138)
Retirement and post-employment benefits	(85,549)	(48,437)
Amounts recognized in the consolidated balance sheets, total	(84,599)	(48,254)
Amounts recognized in other comprehensive income (before tax) consist of:
Net actuarial loss	122,641	78,983
Net prior service (credit) cost	(1,300)	(1,734)
Amounts recognized in other comprehensive income (before tax),total	121,341	77,249
Amortizations expected to be recognized during next fiscal year (before tax):
Amortization of net loss	7,558	5,100
Amortization of prior service credit	(450)	(434)
Amortizations expected to be recognized during next fiscal year (before tax),total	7,108	4,666
Additional information
Accumulated benefit obligation for all defined benefit pension plans	260,536	213,585
For defined benefit pension plans with benefit obligations in excess of plan assets:
Aggregate benefit obligation	266,377	216,567
Aggregate fair value of plan assets	180,075	166,992
For defined benefit pension plans with accumulated benefit obligations in excess of plan assets:
Aggregate accumulated benefit obligation	255,128	208,404
Aggregate fair value of plan assets	180,075	166,992
Other Benefits [Member]
Change in benefit obligation
Benefit obligation at beginning of year	31,398	34,294
Service cost	138	305	285
Interest cost	675	1,243	1,439
Plan amendments	(14,034)	0
Actuarial (gain) loss	223	(2,396)
Benefit payments from fund	0	0
Benefit payments directly by Company	(1,968)	(2,271)
Expenses paid from assets	0	0
Medicare Part D subsidy	108	223
Foreign currency exchange rate changes	0	0
Benefit obligation at end of year	16,540	31,398	34,294
Change in plan assets
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	0	0
Benefit payments from fund	0	0
Expenses paid from assets	0	0
Foreign currency exchange rate changes	0	0
Fair value of plan assets at end of year	0	0	0
Funded status at end of year	(16,540)	(31,398)
Amounts recognized in the Consolidated Balance Sheets consist of:
Other assets	0	0
Other liabilities and accrued items	(1,472)	(2,663)
Retirement and post-employment benefits	(15,068)	(28,735)
Amounts recognized in the consolidated balance sheets, total	(16,540)	(31,398)
Amounts recognized in other comprehensive income (before tax) consist of:
Net actuarial loss	275	52
Net prior service (credit) cost	0	0
Amounts recognized in other comprehensive income (before tax),total	275	52
Amortizations expected to be recognized during next fiscal year (before tax):
Amortization of net loss	0	0
Amortization of prior service credit	0	0
Amortizations expected to be recognized during next fiscal year (before tax),total	0	0
Additional information
Accumulated benefit obligation for all defined benefit pension plans	0	0
For defined benefit pension plans with benefit obligations in excess of plan assets:
Aggregate benefit obligation	0	0
Aggregate fair value of plan assets	0	0
For defined benefit pension plans with accumulated benefit obligations in excess of plan assets:
Aggregate accumulated benefit obligation	0	0
Aggregate fair value of plan assets	$ 0	$ 0