Health Care, Pension and Other Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net periodic benefit cost:
Service cost	$ 873	$ 883	$ 2,621	$ 2,649
Interest cost	3,895	4,017	11,685	12,050
Amortization of:
Prior service cost (Credit)	(164)	(164)	(492)	(492)
Actuarial loss	626	326	1,878	978
Net periodic benefit cost	5,230	5,062	15,692	15,185
Health Care Pension and Other Benefits (Textual) [Abstract]
Percentage of employees eligible contributions matched by employer	6.00%
Domestic Defined Benefit Pension Plans [Member]
Net periodic benefit cost:
Service cost	4,007	4,226	12,021	12,679
Interest cost	4,707	4,507	14,121	13,521
Expected return on assets	(11,610)	(10,578)	(34,831)	(31,733)
Amortization of:
Prior service cost (Credit)	408	416	1,226	1,246
Actuarial loss	4,876	4,735	14,630	14,207
Net periodic benefit cost	2,388	3,306	7,167	9,920
Foreign Defined Benefit Pension Plans [Member]
Net periodic benefit cost:
Service cost	918	501	2,814	1,490
Interest cost	1,061	1,040	3,225	3,079
Expected return on assets	(662)	(720)	(2,008)	(2,130)
Amortization of:
Prior service cost (Credit)		8		22
Actuarial loss	215	347	650	1,027
Net periodic benefit cost	$ 1,532	$ 1,176	$ 4,681	$ 3,488