Pension and Other Postretirement Benefits (Details 5) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Accrued liabilities	$ 8,233	$ 8,225
Accrued retirement benefits	115,057	80,884
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Other assets	14,502	39,149
Accrued liabilities	3,186	3,334
Accrued retirement benefits	72,013	35,959
Accumulated other non-owner changes to equity, net	(107,614)	(67,422)
Net actuarial loss	(106,805)	(66,015)
Prior service costs	(809)	(1,407)
Defined benefit pension plans, U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Other assets	10,620	35,550
Accrued liabilities	2,810	2,707
Accrued retirement benefits	59,952	28,524
Accumulated other non-owner changes to equity, net	(86,925)	(48,564)
Net actuarial loss	(86,399)	(47,538)
Prior service costs	(526)	(1,026)
Defined benefit pension plans, Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Other assets	3,882	3,599
Accrued liabilities	376	627
Accrued retirement benefits	12,061	7,435
Accumulated other non-owner changes to equity, net	(20,689)	(18,858)
Net actuarial loss	(20,406)	(18,477)
Prior service costs	(283)	(381)
Other postretirement benefit plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued liabilities	5,047	4,891
Accrued retirement benefits	41,767	41,352
Accumulated other non-owner changes to equity, net	(7,675)	(5,804)
Net actuarial loss	(8,212)	(6,885)
Prior service costs	$ 537	$ 1,081