Property, Plant and Equipment (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Property, Plant and Equipment [Abstract]
Depreciation of property, plant and equipment	$ 63,875	$ 62,401	$ 129,666	$ 124,325